146
NPS ARCHIVE 1958 WITTER, R. DEVELOPMENT OF A DESIGN PARAMETER FOR THE UTILIZATION OF EXHAUST GAS ENERGY OF A TWO-STROKE DIESEL ENGINE ROBERT W. WITTER AND JOHN F. LOBKQVLCH
NPS ARCHIVE1958WITTER, R.
DEVELOPMENT OF A DESIGN PARAMETER
FOR THE UTILIZATION OF EXHAUST GAS
ENERGY OF A TWO-STROKE DIESEL ENGINE
ROBERT W. WITTERAND
JOHN F. LOBKQVLCH
DUDLEY KNOX LIBRARYNAVAL POSTGRADUATE SCHOOL
NTEREY CA 93943-5101
*L
DEVELOPMENT OF A DESIGN PARAMETERFOR THE
UTILIZATION OF EXHAUST GAS ENERGYOF A
TWO-STROKE DIESEL ENGINE
by
ROBERT W. WITTER, LIEUTENANT , UNITED STATES COAST GUARDB.S., United States Coast Guard Academy
(1951)
and
JOHN F. LOBKOVICH, LIEUTENANT, UNITED STATES COAST GUARDB.Soj United States Coast Guard Academy
(1952)
SUBMITTED TO THEDEPARTMENT OF NAVAL ARCHITECTURE AND MARINE ENGINEERING
on26 May 1958
IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THEDEGREE OF NAVAL ENGINEER
andDEGREE OF MASTER OF SCIENCE
IN NAVAL ARCHITECTURE AND MARINE ENGINEERINGat the
MASSACHUSETTS INSTITUTE OF TECHNOLOGY
ABSTRACT
DEVELOPMENT OF A DESIGN PARAMETER FOR THEUTILIZATION OF EXHAUST GAS ENERGY OF A
TWO-STROKE DIESEL ENGINE
by
Robert W„ Witter, Lieutenant, U.S., Coast Guard
John F. Lobkovich, Lieutenant, U.S. Coast Guard
Submitted to the Department of Naval Architecture and MarineEngineering on 26 May 1958 in partial fulfillment of the requirementsfor the degree of Naval Engineer and degree of Master of Science inNaval Architecture and Marine Engineering
,
Examination and evaluation of available exhaust-gas energy andoperating performance of a two-stroke General Motors 71 series , dieselengine led to the development of dimensionless parameters, related asa single line function, to be used in design and performance estimatesof two-stroke engines.
Thrust measurements were made of the exhaust gases impinging ona flat target plate for a GM3-71 laboratory engine with a single activecylindero Two nozzles, having ratios of nozzle area to piston areaequal to 0.025 and 0.05, were investigated. Indicated engine powerwas determined from pressure indicator cards. Flow coefficients ofthe GM-71 engine were determined for the two-valve and four-valveheads and the figure-8 cylinder liner.
A comparison of effective exhaust-gas velocity was made to checkthe correlation of two-stroke diesel engine exhaust energy utilizationto that of four-stroke spark-ignition engines « It was found that two-stroke experimental results were not independent of nozzle area.
Thesis Supervisors C. F. Taylor, Professor, Mechanical Engineering
Cambridge,, MassachusettsMay 26, 1958
Secretary of the FacultyMassachusetts Institute of TechnologyCambridge 39, Massachusetts
Dear Sirs
The attached thesis entitled "Development of a Design Parameterfor the Utilization of Exhaust Gas Engery of a Two-Stroke DieselEngine" is herewith submitted in partial fulfillment of the require-ments for the degree of Naval Engineer and degree of Master of Sciencein Naval Architecture and Marine Engineering.
Respectfully,
ACKNOWLEDGEMENTS
The authors would like to express their appreciation for the aid
and advice given them by the faculty and staff of the Sloan Automotive
Laboratory of the Institute.
Particular credit and thanks are given to Professor C F„ Taylor
for his help 5 suggestions and criticism without which this work would
not have been possible.
TABLE CF CONTENTS
LIST OF SYMBOLS ii
LIST CF FIGURES !
I. INTRODUCTION 1
II. PROCEDURE 3
III. RESULTS 7
IV. DISCUSSION OF RESULTS 13
V„ CONCLUSIONS AND RECOMMENDATIONS 15
VI, APPENDICES 17
A. DEVELOPMENT OF DIMENSIONLESS PARAMETERS I8
Bo ESTABLISHMENT OF ENGINE TEST OPERATING CONDITIONS 19
C. SUMMARY CF DATA AND COMPUTATIONS 28
D. SAMPLE CALCULATIONS &E. ENGINE FRICTION 57
F. BIBLIOGRAPHY 59
LIST OF SYMBOLS
BMEPC
BMEPM
F
F«
FMEP
FMEPc
IMEP
K
Km
M chart
Mcor
Mp
Mr
N
Pa
?E
PT
Pi
P,
Ap
R
Rs
Piston Area (in )
Nozzle Area (in )
Corrected value of brake mean effective pressure (psi)
Measured brake mean effective from dynamometer (psi)
Fuel air ratio based on air trapped in cylinder (dimensionless)
Overall fuel air ratio (dimensionless)
Measured friction mean effective pressure for 3 cylinders (psi)
Corrected friction mean effective pressure for 1 cylinder (psi)
Engine indicated mean effective pressure as determined fromindicator card (psi)
Flow coefficient (dimensionless)
Mean value of flow coefficient (dimensionless)
Uncorrected air flow rate through ASME square edge orifice(lb/sec)
Corrected air flow rate (lb/sec)
Mass flow rate of fuel (lb/sec)
Total mass flow rate (Mcor+- Mp) (lb/sec)
Engine revolutions per minute
Barometric pressure (wHg)
Static pressure in exhaust pipe ("Hg gage)
Static pressure in exhaust tank ("Hg gage)
Static pressure in inlet air receiver ("Hg gage)
Static pressure before flow measuring orifice ("Hg gage)
Pressure drop across the flow measuring orifice (nH20 gage)
Universal gas constant
Scavenging ratio (dimensionless)
-ii
Tjj; Exhaust gas temperature in pipe (°F)
Tj Engine water jacket temperature (°F)
T, Inlet air temperature before flow measuring orifice (°F)
T Mean time average thrust force (lb)
TMEP Turbine mean effective pressure (psi)
Vc Clearance Volume of cylinder (ft )
a Velocity of sound in air (ft/sec)
ag Velocity of sound in exhaust gas (ft/sec)
u Mean velocity of exhaust gas through the nozzle (ft/sec)
S Piston speed (ft/min)
Z Mach index factor (dimensionless)
P Engine brake horsepower
F Trapping efficiency (>?S/RS )
ys\ Indicated thermal efficiency of engine
2?kk Kinetic blow down efficiency of turbo charger
2? s Scavenging efficiency
y s Scavenging density (#/ft^)
- iii -
LIST OF FIGURES
Page Number
Figure I. Typical Curves , Cylinder and Exhaust PipePressure versus Crank Angle 6
Figure II. Comparison of Effective Exhaust-gas Velocityfrom a Single Cylinder Engine 8
Figure III. Relation of Exhaust-gas Thrust and IMEP fora Single Cylinder Two-stroke Diesel 9
Figure IV. MEP Relations for Utilization of Exhaust-gasEnergy 10
Figure V. Thrust and Brake Power Relation, GM-71 Diesel(0.05 Nozzle) 11
Figure VI. Thrust and Brake Power Relation, GM-71 Diesel(0.025 Nozzle) 12
Figure VII. Inlet and Exhaust Flow Coefficients (GM-71) ?U
Figure VIII. Air FloWj, ASME Square-edged Orifice 49
Figure IX. Expansion Factor (l) 50
Figure X. Scavenging Efficiency versus Scavenging Ratio 51
Figure XI. Fuel Rotameter Calibration Curve, GM-71 Engine 52
Figure XII. Friction MEP versus IMEP for GM-71 Diesel 58
- IV -
INTRODUCTION
Certain experiments aimed at raising the power of two-stroke
diesel engines by means of exhaust gas turbochargers were carried out
a long time ago^ but it is only in recent years that successful systems
have been developed o The reason for this slow development is that in
two-stroke diesel engines the conditions for pressure-charging are not as
favorable as in four-stroke engines Before pressure-charging „ the cyl-
inder must be scavenged to evacuate the exhaust gases 5 howeversscaveng-
ing and pressure-charging must be carried out without any help from the
piston
Pressure-charging introduces more air into the cylinder than is
possible under atmospheric pressure . In this way a greater quantity of
fuel can be burned and thus raise the power of the engine » Instead of
dissipating the energy contained in the exhaust gas by throttling in
valves or portSj, an obvious step was to utilize it in an exhaust-gas
turbine in order to recuperate some or all of the power required to
drive the scavenging air pumps. The power produced in the turbine by
the exhaust gases is not always sufficient to cover the compression of
the scavenging and pressure-charging air ? in which case some systems
employ a mechanically driven scavenging pump in series or parallel with
the turbocharger c
Previous experimentation indicates generally feasability studies
of turbocharging applications to certain selected commercial engines.
Since the design of an exhaust-gas turbocharger is largely determined
by the thermodynamic requirements of the enginesthis thesis is an
attempt to examine and evaluate exhaust-gas thrust measurements and
_ i _
engine operating characteristics of a two-stroke diesel engine (General
Motors GM-71) . From this experimentation, the development of related
design parameters for the practical utilization of exhaust-gas energy
is proposed
•
PROCEDURE
1. Experimental Arrangement,
The experimental aspect of this study was conducted on a standard
General Motors 3-71 series engine. One cylinder of the engine was fitted
with an exhaust pipe to which nozzles of various areas could be attached.
The exhaust gases were directed to impinge on a flat plate mechanical-
hydraulic force measuring apparatus. The two cylinders of the engine
which were not fitted with the nozzle arrangement were modified in the
following manners
a. The inlet ports and exhaust manifold were blanked off so
that there was no air flow through these cylinders
.
b. The fuel rack was disconnected so that there was no fuel
flow to these cylinders
„
This arrangement worked satisfactorily. However, it imposed the
additional problem of accurately determining the friction mean effective
pressure and the brake mean effective pressure for the single active
cylinder. For a discussion of this phase of the study, see Appendix E.
The experimental range of fuel-air ratios and scavenging ratios
that were covered are shown in Table I c .
- Table I -
Range of Experiments
Nozzle Area Ratio Fuel-Air Ratio Scavenge Ratio
0,05 0.0175 - 0.0420 1.10-2.20
0.025 0.020 - 0.0560 0.60 - 1.50
Although the engine was operated in excess of its rated value of
indicated mean effective pressure, operation was satisfactory and under
- 3 -
no operating load did the engine appear to be laboring
„
Instrumentation was accomplished so that at each operating point
it was possible to measure the following experimental data:
a* Air and fuel flow
b Inlet air and exhaust gas temperatures
c. Inlet receiver j exhaust pipe and exhaust tank pressures
d c Engine dynamometer and thrust force
e„ Engine cylinder pressure as a function of crank angle
fo Engine operating conditions
In addition to the above data^ typical measurements of simultaneous
cylinder pressure and exhaust pipe pressure were recorded as a function
of crank angle for each nozzle „ These diagrams clearly indicate the
dynamic conditions that exist in the exhaust pipe while the engine is
operating*, See Figure I for the relation of cylinder pressure and ex-
haust pipe pressure*
Experimentation was also conducted to determine what effect the dis-
tance between the force plate and the nozzle face would have on the
thrust readings. It was found that the thrust force peaked at a dis-
tance of about 2W and was then relatively independent of distance to
a distance of lfen when it commenced to fall off . Experimentation was
run with distance from nozzle face to force plate set at 2^".
2. Computation Procedure
The engine mean effective pressure was determined from the crank
angle-pressure indicator diagrams. Engine brake horsepower was computed
from the dynamometer brake load and corrected as outlined in Appendix E„
Turbine mean effective pressure was determined from an equation derived
on the basis that the turbine system was utilizing blow down energy of
- U -
the exhaust gases e In order to determine turbine mean effective pressure s
it was necessary to make the following assumptions?
3?kb~ ^.75 where ty^b ^s the kinetic blow down efficiency of the
turbine
Tj1'• = 0»4.6 where 2?i * s -t ^le i^i^ated thermal efficiency of the
engine
.
These values of efficiency were taken from the best available source
All dimensionless parameters were then computed and placed on separate
computation sheets so that the results may be easily verified if the
reader so desires e See Appendix A for development of dimensionless
parameters
3. Presentation of Results
The experimental data was taken under two different sets of condi-
tions for operationo On the 0„025 nozzle$the inlet pressure was main-
tained constant for all runso When conducting the experimental phase
of the o05 nozzle j, the runs were conducted at essentially constant
scavenging ratios „ It was possible to correlate the data taken under
both conditions but it was found that considerably less effort was re-
quired if the engine was operated at constant scavenge ratios
.
Figure I
(tt//?sc/g\ nvos vni&c/s
RESULTS
The results of this experimentation are presented in Figures II
through VI j, which follow
„
Figure II presents a comparison of effective exhaust-gas velocity
from a single cylinder engine „ The ratio of effective gas velocity
and sonic velocity at exhaust temperature is plotted against a dimen-
sionless parameter involving nozzle downstream pressure,, nozzle area^
gravitational constant9total gas flow rate 9 and sonic velocity at
exhaust temperature
.
Figure III shows the dimensionless relation of exhaust-gas
thrust and single cylinder engine IMEP 6
Figure IV presents the dimensionless MEP relations for the utili-
zation of exhaust-gas energy,. The ratio of engine IMEP plus turbine
MEP to engine IMEP is plotted against the same dimensionless IMEP
parameter used in Figure IIIo
Figures V and VI present a dimensionless relation of thrust and
brake power for the GM-71 dieselo For the 0„05 nozzle scavenging
ratio was held constant and for the o 025 nozzle inlet air pressure
was held constant
1
Figur<
1
. II
1
k
1N& ^
1in
i
k ^
* 1
^^
1
\
1^ 1*N
/
\
1to
/
C\N.
lr fX\
7f
\\j
r
c
MA/ /6
x:
i
J, 4- < / —- -
Qfc
o
,5 9
1 /x*
-T5
1
h /<
c
c SS7
j>>
Jk -*+*<
^
V**/^ sy.^r
~ps
Figure III
-05
1\
Hto
^JJ^
u.
^
^1
JO.
^ *<* §$ £
1
0- *
—
I
r^
s
I
s^
o» CO t"* <o <n > cr>
<c> Q Ci <3 CJ <3 Q
QD
V0.
NO UJ
1
«*«
M
- 9
A/8
/,/?
A/6
1/4
/J3
A/Z
/.//
/./O
Figure IV
\MLp yf €LAT,'0A/S
\Ura fZATAW Of
fO/
£XHAU
?
ST '&/ s £A/s/eov
\
\
\
o AA
+ Am
t -0.0
- a.&
zs Ao
v k
\\
'
\\° A
IME P-hTME P \IMEP i k 4
\/,07
/.06
/OS
Q
o\\
O v
J
\A A
NA
vi
\
f-Wr-
/03
/.OZ
/.Ol
\\ 3
lh\EP*-t\?*%° y-.? f-sa
1,00 PIT« Q.£
/00 ZOO 300 400 500 &0O 70O BOD 900 /000 //OO /200
- 10 -
Figure ¥
A 00
O.QS
0.90
0.Q5
0.80
0,7S
O.10
O.bS
'A/7
F//^--0 030
0,60
%--o.ozo
~HRUST AND 3/?4K£ P0W£R Rel/\t/om
A/ozzl£ : ao5~
2 ,tf 7
u
»0 ^> Vn
o> <X 00
<S ^' Q
hCJ
SS•^
ss
12
DISCUSSION OF RESULTS
The comparison of effective exhaust-gas velocity presented in
Figure II was made at the suggestion of the thesis supervisor. The
original test results of reference (5) were from a single cylinder spark-
ignition aircraft engine operated over a wide range of engine speedss
inlet manifold pressures., exhaust pressures,, and nozzle areas and were
plotted close to a common line 6 However , experimental data of this
thesis separated s though within a fairly uniform bandsto distinct regions
for the respective nozzles and were below the common line indicated
Variance of fuel-air ratio and scavenging ratio had no evidenced effect
„
These results occurred in the region where high gas velocity (high ex-
haust thrust) utilization would be most significant
„
This finding may be attributed to the larger overall air-fuel flow
rate of the diesel engine which overbalances the lower exhaust tempera-
ture effects resulting from the method of cylinder charging and scaveng-
ing o
In general^ it may be concluded that exhaust-gas thrust increases
(2 5)with a reduction in nozzle area until a critical area is reached ,p
The optimum size is the one resulting in the largest sum of engine
MEP plus turbine MEP minus compressor MEP C The relations presented
in Figures V and VI also showgupon comparisons the availability of
greater thrust by utilizing the smaller o 025 nozzle under conditions
of the same brake power j, inlet air flow s scavenge ratio p and fuel-air
ratio in the laboratory engine „ This finding further emphasizes the
generally known fact that to effeetively supercharge a two-stroke
engine^ it is necessary to raise the exhaust pressure by some means«
- 13 -
Figures V and VI, involving brake power relationships , are some-
what limited in their usefulness except when comparing the laboratory
engine under varied operating conditions,,
The results presented in Figures III and IV are considered most
useful for design purposes <> Indicated MEP relations provide a better
basis for comparison and correlation of engines of differing character-
istic geometry and operating conditions** The use of Figure IV in con-
junction with basic (i eo?preliminary) design analysis should broaden
the scope of performance estimates of two-stroke engines «,
Analysis of data, such asIM~^pME at th™st parameters as a
function of ^E/p. should give additional information as to nozzle area
and exhaust pressure level for supercharging of two-stroke engines
The practicability of pressure-charging by means of an exhaust-
gas turbocharger alone was not investigated for this engine Such
analysis would be of interest
„
In a blow-down method of exhaust-gas energy utilization;, the
length and diameter of exhaust pipe to the turbine nozzle would appear
to be of some importance. These effects were considered but not investi-
gated o
14
CONCLUS IONS AND REG OMMENDAT IONS
CONCLUSIONS
1, It was not possible to correlate the utilization of exhaust gas
energy of a two-stroke diesel engine as a single line function with
the parameters that were developed for single cylinder tests using
aircraft engines. Although qualitative correlation to the data of
Pinkel^' was obtained^ the experimental results of this thesis indi-
cated that the effective gas velocity relations were not independent
of nozzle area,
T ffrt IMEP + TMEP2, Correlation of the dimensionless parameters »g— and TMEp
IMEP x A xto
,
P 6° as a single line function is possible for use inMj ag
design and performance estimates of two-stroke engines,
3, Exhaust-gas thrust increases with a reduction of nozzle area.
RECOMMENDATIONS
P /1, Analysis of MEP and thrust relations as a function of E/p
o should
be conducted to give additional information as to nozzle area effects
and exhaust pressure level for the supercharging of two-stroke engines,
2, The experimental data should be further extended to determine the
practicability of pressure-charging with an exhaust-gas turbocharger
alone. Plotting™EF * jJH = CMEP as a function of the parameter
IMEP
indicated in Figure IV would provide an additional useful design instru-
ment.
15
For further experimentation:
a. investigate the effects of exhaust pipe length and diameter
in the utilization of blow-down energy and the influence of
length and diameter on the design functions developed in this
thesis
o
b. using other two-stroke engines, including opposed-piston, check
the developed design parameters.
c. operate the laboratory GM-71 engine at constant values of
scavenge ratio (Rs ) for ease of operation and interpretation
of results
- 16
APPENDICES
- 17 -
APPENDS A
Development of Dimensionless Parameters
The use of the methods of dimensional analysis has long been recog-
nized as a valid and extremely useful experimental technique. The number
of factors controlling a physical system, such as a diesel engine and
turbocharger system, are many and it is only by the use of dimensional
analysis that experimentation can be logically planned and the results
accurately interpreted.
By holding all dimensionless groups essentially constant, except
one, it was possible to examine the effect of that parameter in relation
to the physical system » The experimental phase of this thesis was con-
ducted with the exhaust thrust force (T) being the dependent variable
while the independent variables were F, Rs , ^E/p.j, s/a?A^/A .
Since these factors controlling the investigated system are extreme-
ly complex, it was felt that the dimensionless parameters developed for
the presentation of the experimental results are the ones most useful in
the consideration of basic design and performance estimates of two-stroke
engines
•
- 18
APPENDIX B
1. Establishment of Engine Test Operating Conditions
It was determined from reference (2) that operation of the GM71
series engine at rated speed (1600 rpm) gave unsatisfactory flow charac-
teristics when examining the engine under supercharged conditions. In
order to approximate the flow characteristics under supercharged condi-
tions, it was attempted to duplicate the dynamic flow conditions of
the turbo-charged GM71T series engine with the laboratory GM71 series
engine o It was felt that operation of the engines at the same Mach
index factors would give essentially the same flow characteristics.
To establish the Mach index factors, it was necessary to determine
the steady state flow coefficients of
(a) GM71 series cylinder head (2 exhaust valves)
(b) GM71T series cylinder head (U exhaust valves)
(c) cylinder liners (intake ports)
Using the mean steady state flow coefficients which were found experi-
mentally, it was possible to calculate an overall mean steady state flow
coefficient for the engine as a complete unit.
The above procedures were followed o It was determined that in order
to duplicate the Mach index factor of the turbo-charged engine, it would
be necessary to operate the laboratory engine at 1285 rpm„ However,
realizing that the dynamic engine conditions cannot be exactly duplicated
and represented by steady state conditions, the decision was made to
operate the engine at 1200 rpm Operation of the engine at this speed
did give satisfactory results for the analysis of exhaust gas energy
utilization
o
- 19 -
2. List of Symbols
A
C
D2
G
K
M
Mcor
Mcalc
P2
Rd
I
z
a
s
y
?
<p
Subscripts
i
e
o
a
orifice area (in2 )
mean steady state dimensionless flow coefficient
orifice diameter (in)
specific gravity of air (l»0)
dimensionless flow coefficient
air mass flow rate (lb/sec)
corrected air mass flow rate (lb/sec)
air mass flow rate calculated from compressible
flow theory (lb/sec)
static pressure before orifice ("Hg abs)
static pressure after orifice
pressure drop across orifice ("R^O)
pressure drop across exhaust valves ("H20)
pressure drop across inlet ports (nH20)
Reynolds number
expansion factor
Mach index factor (dimensionless)
velocity of sound in air (ft/sec)
piston speed (ft/min)
super compressibility factor
density of air (lb/ft3 )
compressible flow function (dimensionless)
viscosity of air (lb/ft sec)
inlet
exhaust
stagnation
atmospheric
- 20 -
3o Determination of Air flow rate through ASME square edge orifices with
flanged taps.
From reference (U)
Orifice equations
M - 0.1U5 D 2
2KY /p- Gy A? (l)
The flow coefficient (K) has been found to be a function of two quantities,
i.e., the "discharge coefficient" and the "velocity of approach factor."
K = — where B = E> 2 / = ±^2 - 0.408
/Z^ /D'
3 '°
the expansion factor (Y) may be determined by the following equations
[••
D2 \4l AP 1/^0
- P,1 -
1 0.41 0.35 [^Q
where Kn — p
Expansion factors for air may be found in reference (4)0
Assuming G & y = 1.0 (this does not introduce any appreciable error)
equation (l) then reduces to
M - V^Ve, * /~ ° (la)
K2
= 0olU5(l-227)2
where 1^ = mean value of K (determined from table 6 reference (4))
x = 0.6150
then M = 0.106 KU Y /~- A.P ( lb )
Since K is a function of Reynolds number and B, a trial and error solu-
tion is necessary. This procedure may be simplified by assuming
- 21 -
% = li,28_M (2)D 2
Solving equation (lb) for M5 the Reynolds number may be found. Using
this value of B^ 9determine K from table (l) s reference (4)»
The mass flow rate is then corrected in the following manner -
Mcor - M (VkJ (3)
4o Determination of steady state flow conditions
»
Since it is unknown if any pressure recovery will take place through
the exhaust valveSj, this analysis is based upon compressible flow theory,,
Mcalc= A a08 ?o, U)
*7d- ('^-' k+1/k)
r - P2
/?o|K - °P/cv
The flow coefficient C is defined as
Mr
_ measured air mas s flow cor (5)calculated air mass flow A ao j q Oo
(h
CA = . JJSSE. _ (6)ao t <?o 3 (p
T08
- 70.9 °F = 530,9 °R
a0j - & /To7 - 1131 fpS
j>o, = J^L = 2118 - 0.0749 lb/ft3
R T0D
53.35 x 530.9
CA'6.0749 x 1131 xp <P
- 22
(7)
CAThe factor 7— was plotted versus crank angle through the range
AP
that exhaust valves and inlet ports are open. From this plot, the mean
value of PA_ was determined by integration of the area under theAP
curves and dividing by the respective abscissa of crank angle opening
duration,. Therefore , also s the mean C e and mean Ci for each type
cylinder head and liner was determined by applying the appropriate
value of A and Ap as follows
g
piston area, Ap - 14.15 in. 2
two-valve , Ae = 2.4 in. 2 (max.)
four-valves, Ae = 2.65 in. 2 (max.)
figure - 8, k± = 5.7 in. 2 (max.)
See figure VII%Inlet and Exhaust Flow Coefficients 5 relations of valve
lift and piston position to crank angle were established from measure-
ments taken on the laboratory GM-71 engine.
5. Calculation of the mean overall steady state flow coefficient for the
engine
.
Schematic engine diagram
1
1 P•a.j
!
Ai Ae
Q Ce
H Pe
23
24
M = CiAi^ai <^(P2/Pi ) = CeAeJ^e (
Pe/P2) (8)
Assuming adiabatic flow of a perfect gas
?2 P2
p" J-T t = T2 = Te
P1
a± = a
It follows therefore that
n /pJ " f: 7^ x^ /p2
Kp2/PJ
-% - ig ^e/pJ
(9)
Pe
P2
Vp^
Defining the overall condition as
M = CA^a (VPi)
Equating equations 8 and 10
CA C-sAiMP
2/Pi)
^(VpJ
Equations 9 and 10 must be satisfied simultaneously
«
The solution to these equations may be found on figure 7-14 reference (ll)
C AFigure 7-12^ "Flow Through Orifices in Series" , relates C/c vs -e—
§
1 ciAi
at constant values of ^e/p^
6 Engine Test Operating Conditions
The Mach index factor (Z) is defined as
7 m characteristic engine area x __S
characteristic flow area Ca
- 25 -
For this analysis - C x characteristic flow area will be defined as
the mean overall steady state value found from paragraph 5» Since
the characteristic engine area is the same for both engines?
S \ / S \
yGM3-71 /GM3-71T
For the GM71 series engine
N = 1600 rpm
k± = 5o7 in2
G± - 0„45 (mean value of C± determined from flow analysis)
e7e = 0o4?4 (Determined from flow analysis)ciAi
from figure 7-1-4 using e^*e = o474 as an entering argument
C/Ci
= OoU
C = 0o44 Ci - 0ol98
CA± = 0„198 x 5c7 - lol28
For the GM71T series engine
N = 2300 rpm
Ajl * 7.9 in2
ifi = 0„476Ai
Due to the fact that the liner flow characteristics on this engine were
Qnot available
9 it was necessary to assume that the ratio of — wouldCi
be approximately the same as that found experimentally for the series
71 engine.
26
Based on this assumption then
Hi = 1.152 Zsta. = .a3Ce C^
C/ci
= °o42 C = 0„42(0 o6ll) - O e 256
CA± - 0.256 x 7.9 » 2 o 02
(JL_) . (JL\\<*1 hi \CAi / 7iT
N71 - ^OOjc^m = 1285 rpm2 e 02
In view of the assumption necessary to find CAi for the series 71T engine
and also due to the fact that static flow conditions will not duplicate
dynamic engine operating conditions,, the decision was made to operate
the engine at 1200 rpm.
2?
APPENDIX C
SUMMARY CF DATA AND COMPUTATIONS
28
-e»en H O O O CV CO C\J \D v£>
"AO^N«0 -4-iN N r-\ H
o o d d d d d d d d
a,
cva,
en »n v\ c- -<} ^n to o o oO nvD s>to«oooa) (M>ooooooooooooooooooooHCV^-C-OOtOCV m C*<-
cv mtoOmc-OOOOOPL, vOOOOOOOOQO
mcncnencnmcn»4--4'-*4'
en
PL,
OCO C^OHO (V tO lAH
enev 3
3
O st^HiAONNOOOtn-4'-4'm»ntnmmmOHrHHiHrHHHHH
ooooooooooov£» -<j- -4- m en en en en en enOOOOOOOOOO
rlodo'dodd d d d
£> sO CV rH CV C-- O O tf> C--£~ -4- 'O o en -4- vO >£> \0 voO en -t tn *n »n >-n y\ in in
* ? t *. * 9 t - -i *OOHHnrlHHHHH
»n CV f» H tG CV \D sO CV HsC cf\ «* c^ H (^ st
- sr w\ tf\Oen-3"--t<m !mLf\vn»nmO H H HH H H H H H
OOOOOOOOOOOCV £^ nQ O vO CV vQ <5 O OCV CO O tf \ E> O O O H HO cv -<jt -4- •<}- -f »n *n *n m
OOHHHHriHriHrl
vO vO CV HO (M>O^OtOCOJ>J>^-£-sOvGvOvOvOO OOOOOOOOOO
rH d d d d d d d d d d
OO
PL,
oPL,
<
PL,
en cv •** o cv -4-vOOvO-J-toOsOOHCVcv mm-4-r--ooooooooOOOOO HHHHH
ocicS(D(Dcio(D d d d
o o so en an -.£ cv ^n to o cv• O O 5 « 6 9 O J > ft
n c^- to mu-\v£>c>»t>S>toto--o r~- co oooooooommmcncNcncnmcncncn
ocv
»nO
crj
PL,
oj>-«4-2>ocnevsotoQcn«eooeoo90«OvOOmtOOOOOHHH en en en en -4- -3- ->t -<r --t
.«-»
ifiOnnOlAOiAOlAOOHHCVCVcncn-^^mOOOOOOOOOOO
- 29 -
_ tr\ CNtO C^y CO vO nO «>sa tf\
"~-f^«. (^^NOiOiHrlHHHHooooooooooo
a}
CM
^ifvMOOvOOHN^sto .Hc^vo^c-tatocococooooooooooooooooooooooo
Oh
CO W\H\0U>H l^rvH'^*^O£>o * 3 a 'i c • • ft
-^OOtOofNsQC-COCOCOCOvO \D CO CO O O O O O O O
u i * * 4 <3 « .-> w a *
O in^vDrHt0 8:»vX)s0v0NO-4" C> CV rH H
oS
CVOcr\OrHH\OOCOCOH WnO iAO C^i-d'^iAiA
OiHHHHrHHHr-HrHooooooooooo
J
IoX
I?
OOOOOOOOOOrHOOOOOOOOOO
HC^\OH«)0«NO<0«0CM mHrJNOOHOINWvOOc^-sr-^hirvtPiinirvirv
OOHHHHHrHfHHH
vOCVCMCOOiC^OiTSOlCVH-*Of>»A«QOOr^HOHHHHHHHHH
OOOOOOOOOOOco
-4" E- CV cvCO O *A tf\ i-j
V\ O CV C^ ~<f« « o « •
O O H H rH H
O «*#o OC 1 3 -i
rH rH H H
tH
lAsftO^CVHOOOO_ OtO^-IP-C^C-C-ISC^^-o ooooooooooh d d o" d d d d d d d
o
C*-0 C^ U"\ CV UN £- CO CO CO
o d d d d d d d d d d
p-,
CM>tOM^(»HvOOrlH<$ tO GO \0 r-i C*\ lC\ir\ IT\*£> \QvO vDM» O O O O O O O
e? » C 4 * t « '-< *lfr *
Ovootoc-wot-cocoooHCV <T\ C> C<-\ C^ C^ C^ 0^
iaOiaO mO ur\Otf\\Q
o o" d d d d d d d d d
30
-€kvM/>»r\mv£)c\iOt!Omco\0tOOOCOONvOOMAH^iAOOOHHrHrHCVPAC^C^o o o o d d d d o d d
asa,
C\i
a,
itmaiaw O h vj-iAir\o oOOOOOtX)C--U^CV r-IOO O O O On o O o^ o o o^
00000000000O\0t0C<SQCVQf^'v0H
4 u « £ 9 ft O C C S *
c\J r^c^\cACViHtX)-<M^vfNtOvr\Cl, OOOOOOOCOC-vOvO
a,
<C\iH-4-CVI>Ot)0Of>->*OrHrHHCVr^^OtOC^vOOHricvnr\
oo
\0\OvO ur\ m -<f -<} cv o vr> cvr-i H rH H H H H o oooooooooooo
6
W CE-t -H
CO I'-o
©
CO oXX)
^ -ri
CO
53C
.1
ir\
S
P?
>H
OOOOOOOOOOH
vOvOvOsD inin-4-cv qn m cv
HdHrlridHHOOO
ir\ m ^J-CV <M cv o c- ocv c- vrv ir\ »4-
. -«* vO sO 10.sDs£)vO\OW^^N-<fCNiC>ir\Oir-i r-\ r-t H <~i iH o ooooooooooooOOvOCVOOOttO CV \0 C-
ir\inir\irvvr\-Ntc^<v onvt\CV
iHHrHHr-ir-HiHrHOdd
vOv£)£>C>-tiOOc>OC--»nvO\OsOv£)vDJ>C^C^-oOOnO O O^ O^ O O O O^ O O Od o* d d ddddoH
oo i^o
0«
tO\0 Q W H UNinHCO NtOHrHOO^r-^OOOiU^C^HHHOOONtO^sfriOHiHrHtHHOOOOOOd d d d d d o" d d d
tOH£*- imOCVU"\r-tHHHQ QtO «ACV iA\Ot» m
CU OOOOOOOtOJ>-vOvO
o
<§•HP•HCO
o
OSO vr\r-0 irsvOvO HvOCV» »
nCVtO -4-vO vO >T» iH^ -<f c<\ r^ CM H333
OQOOOmOmOOo d d d d d d d d
- 31 -
SUMMARY SHEET - FLOW COEFFICIENTS
Series 71 Series 71T Figure 8 liner
Lift CA ^/ap CA °Va:p Position CA ca/ap
3.24 0.2290
0.05 0.315 0.0223 0.564 0.0399 0.20 3.24 0,2290
0.10 0.609 0.0431 1.03 0.0728 0.30 3.23 0.2281
0.15 0.922 0.0651 1.368 0.0966 0.40 2.58 0,1825
0.20 1.13 0.0799 1.70 0.1201 0.50 2,11 0.1490
0.25 1.31 0.0925 1.814 0.1281 0.60 1.576 0.1114
0.30 1.475 0.1041 2.03 0.1435 0.65 1.262 0.0893
0.35 1.526 0.1078 2.14 0.1512 0,70 0.821 0.0580
0.4.0 1.570 0.1110 2. 26 0.1598 0.75 0.521 0.0368
0.45 1.612 0.1140 2.27 0.1603 0.80 0.277 0.0196
0.46 1.661 0.1175 0.90 0.122 0.0086
- 32 -
aCT* CT* G> CT^ Q> Q^ O^ Q^ O^ O^ vO vO vO vD nO vO ^O vO vO vO
• » » » » « » •> » •» e » « » » * > a aooooooooooono^oo^oo^ono^onon
mmOOOD-mOCM C-OQOC^QCMOCMOOmc\ltomHmc\10t>mC>--3- C\JOOC,-mmr-IOvnxn~4--4--<}-^}--st->tr^c^cf\c^cnr^r^cv oj cm cv H
*iPQ
o+3o
R«
to inoEi O<a • •
W^ 3NEH
o 8H s
in m in CM CM CM mC^r^C^os-^tONC'-C-tXJr^-^vOHOrHvrNvOHCviO
3 i * '• • 3 » rt g <i 9 ? % « <] | 3 « 4 i'
inCMtOinH-^HtOinH-^i-IONvOCMcnrHONvOCMHrH rHH HH HH
in in m m in m inKfNnt<\^OiOrlH^OOVrlHttHHr|0(0CV HOOC^CVHOOC>-njOOO\C^Oip-jOOC^-HHH iHHH HrlH rHHH
mmmmmmmmmmmmmminmmmminHHHHHHHHr-lr-IHHrHHr-liHr-IHHrHOOOOOOOOOOOOOOOOOOOOopoocMOmototooocMCMCMC--mcMCMOinO moN -4'0-<hOCV£>Omc*-0 -4«M» O^HC^^in -«4-ca r^ cm in-^t-«tc^r<^vOinin-4Tr\j>-vOvOin-«4-
in in O in in in inCV Or--tH-4-HOC,--4-vD -«t CM ho o o to r- m•^•^(ntnc^C^tnWCVCVWWCVCMCVHWHHH
t»00HHC\injc\iCN2cvfncnc°immmmcvHH^tOtOtOtOtOtOCOtOtOtOtOtOtOtOtOtOtOtOtO
0-4
<
Oh
c^cncncnr^tototototo cncnr^o^cntototototoCVCVCVCVCVHHiHHHHHrHrHH
in in iniH\OOOino-<i'cnvOHC*-int»HOrNiini><VH
t » • • « »>•<# f * * 1 « * * Q » 4 -9
O OOvO^O sf-^f^W HOOtOC*-C^-^Q-<fc^c<-\CMiH(^OiWCVWNNfVCVWHHHHHHHHrlH
Oh
in to in int-H-^C^iHHvOvOtOCAin-^tC-OOC-Or^tOvOHOtOC-vOvO-^tcnCM pHOOtXlttOr^-^f-^-sJ-CVrH
H•HO
Ph
OOOOOOOOOOOOOOOOOOOOCOtOtOtOtOtOtOtOtOtOtOtOtOtOtOtOtOtOtOtO_J _,_,_1 _1 _l_, p, rl rl Hr)Hrl HHrlr-{ r-\r-\ H H iH H
j3 rH cn ini> c> H cn inc- o h m in i> o H on in {>• o3 in m in in in vO vO \0 vO v£» C- I> C^ C*- l>- to to to t» «0
- 33 -
cvt©€>%0^~^^cA<^^fr\\0CV^»jna£\c^>-»4"f--l'>4'ocv t© ^too^cAC>cA^H^HNOOTO»--j*4rOc<\c^cACVCVHCAC^CVCV^^cn^CVCV-^-vfrencACV
(x< oooooooooooooooooooooooooooc«63ooeeooo60oooooooooooooooooooo
.#
»r\0 cv cv cv nr\*r\c«-imOff*=cv umo o cv 2>umaO\0 CV C>\OCV^HCQU"\iH'»4, HtO&riCV«\H!tO ,tf\'N1NCVHHHN"(MOJHHHO O
HHHOitVHHrlCMNHH aOOQOQOQO'OOQOOb'OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO-<tCVv0v£>v£>c<AOC^iH^tt)%0«Qt»!ur\>AS,«-s0H«>
r cv oi cv cv cv t«- to c*- to to 5fr -4- 5r -4- *r\ =4- -si- vO «"% anL_ kJ-^ ^ ^ -4 ^ -4- -^ -4 ^4 ir\ tf\ sr\ *r\ ir\ \£> \£) vO vO vOe>OGdd0OO0OOOQe«06O«OOOOOOOOOOOOOOOOOOOOO
1A M\vO O C*- ->t O H H\D vO vO \D -^vO *A
t* l>- fr» C*"
ooooooooooooooooooooo o o O O <A oCV CV CV CV CV cH , H O O \D vJQ -ooooo^ooooo^to«o«cto«o c-
02C^tO\D^O^O«AOHC>C^tO0^«OtX) vf\ O «J iH c^ -4;Hr)rlHHO>>(>^«)tO>A<A>AKMAriHriHHoeooooooooeoooooeoooNNCVOItMHHHHHrlHHrlHriHrlriH
«JTNo
vOOOCV -4-OMH^CV iAHAiH^CV OOO O vO C\^CAC^CVrHHHOOC>a^C>tOtOtOtOtOt>-C^?N888888888&&££&&&££SS»»6eeoeoo*ooceec>e«ocOOOOOOOOOOOOOOOOOOOOOv -4 0^(>0^0N 0^(M3v '>t'«0^0 (H ^ sO HI sO HvO HWHf>-4'H-4HG,
'fv= |A |iAfr\WOaN^OC0vD lA• oooot»o«soo»««>>dcee3o^-tCACACAfACACVCVCVCVCVCVSV t-i r-i <H <H H r-i
3
•rf
vO^OtQOO^O^O^^tOHOCV r\CV^DifN!if\irN«Mrv(Acr\cAC<>H H H i—\ H H &S88&
OcnOCMo o otoo to to CO £* £*HHHHHHHHOOOOOOOOOOOOOOOOOOOOOOOOO
o
WWM<0««WWM««5tO,t0«QtlQ(AiA>A>AinCV cvH cv Cfi C> Cf- (> C?> -^ ^ -"^ -4 ^>0 \0 %0 vO vO
•dS&S&&&8 8 88 888888OOOOOOOOOOOOOOOOOOOO
b-So
£«- O vO CV (>OOOtOOT^\HCVCV^^<r\CA<ncACAc^r^r^cvcvcv6iooooeeoooooooorHrHrHiHrHpHfHiHrHljHrHrHiHiHrHrHrHiH
CV CV iH H HfACACACV H W\>->4->4h-4, «4\OxOsQ\OvOC^C^CT^Q^CT'-O^CJ^Cy'C^O^C^O^O^Q^O^O^CT^O^O^CS
>H O^C^O^C^O^O^CJ^O^O^O^CJ^O^O^CJ^CJ^O^O^O^O^O^ooooooooooooooooooooOOOOOOOOOOOOOOOOOOOO
cu
PL,
to to g^so, cv o""4 *"4
•vJ-CVO (T^CVsOCVtOOtO if\\£> CV 0-4HCA..NC0g\0NOc^4-4if\»Al30t0 0^O\O(^(^nr|,
iN(\iWW(nWWNWWHHHHWHHHHriooooooooooooooooooooe«Qoooeooooooocooooooooooooooooooooooooo
P-,
O O U\ nrv -4 -4 ~4s0 Ov^HtOsOCVtOCQtO WHvOCAHOtO\OvO «<4 CV H OO Os J> *f\ CA O OOtOsOt»t01>iM^t>C>-I^Es-\OEs"^0'vO\OsOvO»A ,<Otf\>r\
rt
Hn*Af>O^Hfr\>A^O\Hf\ I>Als, C>H(r\>AE^O^»f\>A>AiA W,0 nO nO %D xD !>• £> fr~ §- E^ tO tO CO to tO
34
CCMPUTATION SHEET
NOZZLE : 0, 05
Run B , L -. BMEPM IMEP FMEPM FMEPC BMEP C
51 15.7 88,3 286 197.7 65.9 220.1
53 12,3 69*1 265.5 196,4 65,5 200,0
55 8,7 48,8 229 c 5 180,7 60.2 169.3
57 5»9 33.2 218.5 185,3 61,8 156.7
59 L<y<4 7.87 175.5 167.6 59.2 116.3
61 14.9 83.8 268 184.2 61 e 4 206 = 6
63 11.7 65.8 240 174.2 58.1 181,9
65 8.7 48.8 218 c 5 169,7 56.6 161,9
67 5.85 32.9 197 164.1 54.7 142.3
69 lo35 7.59 148 140.4 46.8 101.2
71 14.45 81.2 258 176.8 58.9 199.1
73 11.6 65.2 227 161 o 8 53.9 173.1
75 9.1 51.1 217.5 166.4 55.5 162.0
77 6.02 33.8 187.5 153.7 51.2 136.3
79 2.12 11.9 157.5 145*6 38.5 119.0
81 13.52 76.1 243 166,9 56.0 187.0
83 11.65 65.5 222 156.5 52.2 169.8
85 9.1 51.1 205 153.9 51.3 153.7
87 6 2 34.8 179 144.2 38.1 140.9
89 2.9 16.3 158.5 142.
2
37.4 121.1
- 35
P«
iHrHrHHIHIrHr-J s—8 Hi i—l rH HICVCVCVCVCVCVCVSVCVCVCVCV HJ H H H
CV CV CV CM
CVCVCVCVCVCVCVCVCVCVCVCVCVCVCVCV
»f\ HT\ Q C*= &Tv CV iAiAOON >Ti«MfMf\cr\crN-<l'icr\-4-ir\'mif\\0 t> C^> !> cv cv cv cv
<-u It '5 >b «5 G * o O fc O I. t '* v.<^(n(ncf\OICMCMWHHHHHHHH
» «> V\ Hf\ O VN W> iTv if\ tf\ Ot-3 e^C^^frf-HOHOnnHO^tOCVOVNCV0fr*C»00«000004<*tifjQ OvU\nOO'IA^rlh>0(T\rHr»«Mr\rl
o-po«
C^OCVCV^tOHHmHHOHcrNHOoveeeoooeoeoaeooHO(^toHO(^tor^oa.tlOHO(^^H H H rH H H
cvo
P-8
E-?'
CVCVCVCVCVCVCVCVCVCVCVCVCVCVCVCV• ooeooeoo«ee»oeoooooooooooooooooOtOO>AiAO«\OiAO>f>tOOiA««tO•sf\0 O CV O^xO r> OCV O 4A CA O v£> CV 00
C-Q
Pm
HvOOHHCOCOOONiiAHICVC'-E^tOtOo 60«ocea6oeoceoo
tr»-<i--<tif\c<Nr<,\c^-4'CV itn cr\ c^ cv cv cv cv
HHHHHCVWNHHHOOOOO
Pm
1T\ tf\ HTV-»* -<}-\0 tOOQOS^-tOCVOtOsOC^fcAOD-ooooc»e«coecoeooOcir» -tvO 5s- to O &\ S -^ *r\ cv cv c^ <r\
Hi Hi Hi rH
P-< CVCVCVCVHHiHHrHHHHHHHH
w\ an *n nr\ an Mr\ »r\ ir»»f\ w\ v\vOttC^^-^iAiAsON CM !n»4HHHOI
CVCVCVCVHHHHHHHHHrHHH
•HO
°t-3 Oia>aOOkm(MAOOOOOOO«\H tOD-r>^-C^t-^t-flOtOt»T»tOtOtOF-
t-ir-ir-^r-ir^j-it-iiHt-{t-\t-iHr-\i-it-{t-\
« HHHHHCVCVCVCVCVO^C\
36
(^
»OH«OO^^OiANvOsfoo u>>
oooooooooooooooooooooooooooooooo
^
Lh
»AOJOJ IA00ON 0> C^tOOQ-to \£> c> f> to vnc> cm» <£> <r\cv o«>OiCVHHHCVHHHCVHHHOi n'HH8QOQOQOOOOOOQOQQOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOH =>triOc\ifr\^«Or«^<^OOitO->±-4-
•
cr- e> -4- oxnu^i^vrv\OvO\0s0tOE*--C^f>tOtOtOt0OEs-'*As!, ^m(^HHtO'^Noooooooooooooooo
01tO£-as0HOOO<T\c\it^Ocf\«r\HC\lH-4-sD^^T^tCO OCV tatJOr^^^-OtO tO t© tO £^ O £-» tO *r\ \£> \0 vO *f\ U"\ »jO vOo©eo«>ooooeooe ooeOOOOOOOOOOOOOOOO
03 vDt»U>C\iOvOCVOCVOt»-4"«>iHC^'Sj-ptj C^N-<i-»r\vD lHiHrvJCV?>-^tX>0^ !iAvDvO^
O <> € 1 8 '*. -. B G oeroHHHHHHHHOOOOOOOO
«MAiA«\OOiW(MOHOptO^O^OO< 88 8888888888% S'8 8
OOOOOOOOOOOOOOOOM in
1 oe CCS
co o &£3 oo
OS
<aj
io
.£oo
H H H H \© H H H rH H H *>£> H H \0 vDen 00 H^f\OOW Ht-O-^TOOOOOO 0O«CO«Ot«40 « ft O
-4^-4-4«Mn(nc^{VNWOJHIHWN
-4\0 «0 O -4- w\ O -4"sJD \OriW "AOt^«4rJO W^H^^tO^OsOOi^H^^OioH H o o o ooooooooooooooooo
S2&888$£8
P tOtO^tOCNJOnAtOCVfVtOS^O^Of^
A &8 8&888&^^»»88S^g oooooooooooooooo
o
•a 5cd
OHOjOIOOO»AHHN01 JAUIMAtt)-4'»<r=4
- -«tKv-E^E^CSC:>0 OO an m an mC^r\(nc^WCvi 6iWCMWCVNHHHHoeoeeeoooeoeoeoeHH r-it—ir-it-iT-ir-it-ir-ir^t-^r-it-irHr-t
v\ -4 -^ ->* v£> iAsO ^AtOtO^-E^OO^tOtOOO OOOOOOOOOOOOOO
a o «ee«o«oaoooooooooooooooooooooo
(U
P-,
V\CM tO ^s|h-4-E»» to Q O o/
O O o o o o
«n «% l!AtOO^>Arlf«H=4* H lA^^^ C^sO^D Q>f^ V\ >n \D tQ o ~4" -4" »n \DHHOOOOOOOOOOOOOOOOOO
OOOOOOOOOOOOOOOOS tO HI «n OO^O O O \OsO O^O WMiASAnOH Oi CVJ CM -5fr «Mtf\ V\ £- £> £>» tO C\ C\ (*\ «n
CN*n£**OHC\MM>OH«,'\W\HHrlHHNNN' O H f^CM «n en
- 37
COMPUTATION SHEET
NOZZLE : ,025
.un B.L. BMEP^M
IMEP FMEP„M
FMEPC BMEPC
3 9.7 54»5 227 172.5 57.5 169.5
5 5.7 32 o 192 160,0 53,3 138,7
7 3.4 19.1 196 176.9 59.0 137.0
9 0.75 4.22 161 156.8 52.3 108.7
11 9.1 51.1 221 169.9 56.6 164.4
13 5.9 33.2 190 156.8 52.3 137.7
15 4,15 23,3 181.5 158.2 52.7 128.8
17 1.95 10.95 143 132,0 41.3 101,7
19 7.5 42.2 187.5 145.3 48.4 139.1
21 6.15 34.5 184 149*5 39.8 144.2
23 3.95 22,0 152.5 130.5 43.5 109.0
25 1.85 10.4 143 132.6 43.2 99.8
27 5.25 29.5 168 138.5 46.2 121 8
29 5,05 28.4 160 131.6 43.9 116 ol
31 3.5 19.65 148 128.4 42.8 105.2
33 1.2 6.75 122o5 115.75 38.6 83.9
- 38 -
DATA SHEET
COMPARISON OF EFFECTIVE EXHAUST-GAS VELOCITY
NOZZLE s 0,20 An = 2.83 in2
Run* Pt Mp T u TEaE
u/aEptAn?oMj.aE
10 29.75 0.1326 3.03 736 960 1519 0.484 6.59
9 29.60 0.0899 1.79 642 991 1542 0.416 9.54
14 29o70 0.1077 2,75 823 1204 1700 0.484 7.26
13 29.75 0.1310 3.43 844 1075 1606 0.525 6,34
15 29.60 0.0906 2.57 911 1335 1790 0.509 8,18
3 29»75 0.1326 2.71 661 832 1415 0.467 7.09
6 29.65 0.1067 2.11 638 940 1501 0.425 8.30
11 29.65 0.1086 2.53 751 1058 1592 0.471 7.67
12 29.60 0.0916 2.07 727 1142 1658 0.438 8.95
NOZZLE g 0.10 An~ 1.415 in2
66 30.30 Ool329 4.07 985 1122 1641 0.600 3.10
76 30.10 0.0894 2.64 959 13a 1799 0.534 4o34
123 30.40 0,1100 3.07 900 1057 1593 0,565 3.95
64 30.25 0.1303 3.36 829 864 1440 0.576 3.61
65 30.30 0.1342 3.71 890 992 1544 0.576 3.27
70 30.15 0.1102 2,89 844 1058 1593 0.530 3.84
71 30.15 0.1098 3.29 964 1213 1714 0.563 3.54
74 30o05 0.0861 1.96 755 982 1538 0.491 4.99
125 30.50 0.1328 4.14 1000 1101 1629 0.614 3.11
*Run numbers refer to Ref.( 2)9from which operational data were taken.
- 39
DATA SHEET
COMPARISON OF EFFECTIVE EXHAUST-GAS VELOCITY
.2NOZZLE : 0.05 An = 0.707 in'
Run pt MT T u TE aEu/aE
rtAnS<MTaE
51 30.29 0.1623 5.55 1037 968 1521 0.680 1.37
53 30.29 0.1611 5.25 1017 910 1478 0.689 1.42
55 30.29 0.1579 4.80 980 850 1428 0.682 1.50
57 30.29 0.1564 4.50 926 802 1390 0.666 1.56
59 30.29 0.1542 4.10 855 750 1342 0.636 1.63
61 30.29 0.1385 4.57 1062 1005 1553 O.684 1.57
63 30.29 0.1361 4.25 1012 950 1511 0.665 I.64
65 30.29 0.1357 4o00 951 888 1460 0.651 1.72
67 30.29 0.1331 3.72 898 838 1418 0.634 1.80
69 30.29 0.1309 3.37 831 760 1351 0.615 1.92
71 30.16 0.1116 3.70 1088 1110 1631 0.665 1.86
73 30.16 0.1111 3.40 985 1032 1535 O.642 1.98
75 30.16 0.1101 3.20 936 962 1518 0.616 2 o 02
77 30.16 0.1089 3.07 909 902 1472 0.616 2.11
79 30.16 0.1064 3oOO 909 817 1401 0.647 2.26
81 30.16 0.0831 2.72 1052 1245 1703 0.607 2.38
83 30.16 0.0822 2.50 978 1152 1663 0.588 2o48
85 30.16 0*0822 2.32 911 1072 1608 0.567 2.57
87 30.16 0.0806 2.10 838 990 1542 0.543 2.71
89 30.16 0.0794 1.90 771 895 1469 0.526 2.93
40
DATA SHEET
COMPARISON OF EFFECTIVE EXHAUST-GAS VELOCITY
NOZZLE : 0.025 An ^ 0.3535 in2
Run pt M T T u TE aEU/aE
ptAnS(M>raE
3 29.41 0.1038 3*35 1040 1100 1629 0.640 0.964
5 29,41 Ooll25 3*35 958 928 1493 0,641 0.964
7 29*41 0.1175 3.40 933 850 1430 O0652 0.964
9 29 o41 0„1223 3,37 888 785 1374 O.646 0.964
11 29,41 0,0797 2*45 990 1195 1692 O.584 1 .<~ j
13 29«41 0.0854 2.50 944 1020 1568 0.602 1.20
15 29,41 0,0896 2.52 905 935 1499 0.604 lo24
17 29,41 0,0947 2.53 860 850 1430 0.601 lo21
19 29*41 0.0529 1<,65 1005 1285 1760 0,572 1 76
21 29,41 0,0585 1,70 935 1160 1670 0.560 1 68
23 29.41 0.637 1*70 859 1015 1562 0.549 1.58
25 29o41 0,0681 1<>72 814 898 1468 0.554 1,64
27 29.41 0.0437 1.25 921 1260 1740 0.529 2as
29 29.41 0,0449 1.25 898 1225 1716 0,523 2ol4
31 29.41 0.0489 1.25 825 1084 1616 0.511 2.08
33 29,41 0„0537 1,25 750 940 1504 0,499 2 o04
41
DATA SHEET
THRUST AND IMEP REIATION
NOZZLE : 0.05
Run TE aE Mt IMEP T t (8q WMTaE
51 968 1521 0.1623 286 5<,55 0*680 526
53 910 1478 0.1611 265 5 5.25 0.689 506
55 850 1428 0.1579 229 5 4o80 0.682 464
57 802 1390 O.I564 218.5 4o50 0.666 458
59 750 1342 Ool542 175.5 4ol0 0.636 384
61 1005 1553 0.1385 268 4*57 0.684 566
63 950 1511 0.1361 240 4o25 0.665 531
65 888 1460 0.1357 218.5 4o00 0.651 502
67 838 1418 0.1331 197 3o72 0.634 475
69 760 1351 Ool309 148 3o37 0.615 381
71 1110 1631 O0III6 258 3 870 0.665 645
73 1032 1535 Oollll 227 3,40 O0642 606
75 962 1518 0.1101 217o5 3o20 0.616 592
77 902 1472 0.1089 187o5 3o07 0.616 531
79 817 1401 O0IO64 157.5 3a00 0.647 480
81 1245 1730 0.0831 243 2.72 0.607 768
83 1152 1663 0.0822 222 2.50 0.588 739
85 1072 1608 0.0822 205 2.32 0.567 705
87 990 1542 0.0806 179 2 o10 0.543 652
89 895 1469
„ IMEPW -
0.0794 158.5 lo90 0,526 620
Mip x ag
- 42
DATA SHEET
THRUST AND IMEP REIATIQN
NOZZLE % 0.025
Run TE aE Mp IMEP T T gQ WMT
aE
3 1100 1629 Ool038 227 3.35 0,640 611
5 928 H93 0.1125 192 3»35 0.641 520
7 850 1430 Ooll75 196 3*40 0.652 532
9 785 1374 0,1223 161 3o37 O.646 435
11 1195 1692 0.0797 221 2.45 0.584 745
13 1020 1568 0*0854 190 2„50 0.602 645
15 935 1499 0.0896 181 5 2o52 0.604 615
17 850 1430 0.0947 143 2.53 0.601 480
19 1285 1760 0.0529 187 5 1.65 0,572 915
21 1160 1670 0.0585 184 lo70 0.560 856
23 1015 1562 0.0637 152.5 1.70 0.549 696
25 898 1468 0.0681 143 lo72 0.554 650
2? 1260 1740 0,0437 168 1.25 0.529 1008
29 1225 1716 0o0449 \6Q lo25 0.523 1008
31 1084 1616 0.0489 UB 1,25 0.511 851
33 940 1504 0537 122,5 1.25 0.499 689
43
vOO =»* «0 ># vO H(M ia rH &A •-£> Ai H O tO O »A (N Ocv O^o »AtO ^O <r\ O t*- to -^O o ca to vQ <A O vacm»A>A»<f^fcAkA»AiA--4c>v0v0 vaia-^d-C^C'-vOvO
-4"\0 CV O ->* H CM O^p-4-ffi^-4-^f-«nt0v0Cs-fr\t00N
»awa»aia»A8Aiaiaia\Ov£>\OvO\QvOvOv£>vO f- C-OOOOOOOOOOOOCOOOOOaOoooooooooooooooooooo
oeooooeocoeaoeaeooooCVCVCVCVOiHHHHHHHiHHiHHHHHiH
rH r-i i-l O (HI• ©ooooeo
rH i—I r—\ rH rH f~b rH rH
j-JrHOi ~4-t0tOQ>HOisDv£>vjDHHHHHC300HHOOOsO vO \D \D ^OO Or—li—liHr-lr-i r-i r-i r-i r-i r-\
5
of o.
Ol
QtO^I^A10C>^t©-<fr<sJ!-HI«)«OSAOO^<A*AC>aoeoooooooeeoooooeoojv -4cv h g\£"s0 ia-4-Hcv o o to O ia cr\ <a H onr^f^cnNNC\iOirJoi(MNHHWHHHiHH
<A HA iA «Ae © o e
\Q*Ag\tO0^tOQtO^iCVOJCxiCVHCMAfCMrH
«MAIA HA
t© ^> t- £•>»£>- CA CM »A OtOSACV rH tO >A-d-AiO r^-lAtV N Oi H H N C\i (V H H
vO lAtO O \QO ilA (A <JvNHH'iArNHWtlOsDsAMSOHOOHW-^-^tOcr\ ^4 *+vO r~5 _J _j ru .»+ tv» rn rt\.
—rH! (H rH «—i rH rH rH rH rH O O ^3^888^^OOOOOOOOOOOOOOOOOOOO
HtX> ~3"tO «A O«A r-i «A »A <A >Qo o ooo £» o
r-j cm to
o oto«0 OJ H H rl «0 ,
OtO !> «ArHtOQN^OE^AiCViACA- *o o oto to to o -
&PrH
HHlOOOrHHOOOrHOOOOrHOOOO
Pn
*H
CM HjTJO O^sO -4-CV ff» «n g% C1- lA H rl«HHOHHrHHOAJ CAO iA- H HH HtnCV W CV HOOOOOOOOOOOOOOOOOOOOo««esQO0ooo oooooeoo©
J Pn
vQt©r^^0^tOHO^^s©^H%0'S*-trHrHON\0=«4-
\OP^C\i0^tf)^^HtOA10^^^rHHE^CVQ\iiAOOOOOOOOOOOOOOOOOOOOvoeoooooooeoo«o«ooooOOOOOOOOOOOOOOOOOOOO
AJtO O^^OE^-^HACAO^ACAsOAl E^tAiAO^tH"^r^i^wcvHf^^cvtVHsrfAc^cvcv-^srf^cncvOOOOOOOOOOOOOOOOOOOO
o o o o c oooocooeoooooooOOOOOOOOOOOOOOOOOOOO
« iiAU^M^iA»A>X)^O^O^D\OC^J>'E>E>*-C^tOtOtOtOtO
- 44
HOW kA »A »A m O iA'^^ o oo to H o^H Oi CO CO -si" -tf iH tQ tH UAO^KAO O u\ tovO W\ »A -st C*- \D \D ^O^i»v£l\00 OCOvO
CL,
0)
sf-^t-^-^corococo^ONOsONO O O O O\0\OvOvOOiOiOiOi O0^OO>vr\>-Aif\sri,
ooooooooecoaaooooooooooooooooooo
I•t
P0)
•H
ft<L>
ft
a-p
vOCO tf\C\i OvOCV QsC\i OtO-^^H^^CO'Si-V\vOrHHOiOiJ'-t--tOO>>»A\Os£)C^
c • e o a <- • o i . « . . e seaHHrHHHHHHOOOOOOOO
tO Oi Q>tO to£= Q>. O Oi to,
iO HHOj~H r~H ir^ i~HI
«0 N«\H tO «>£tO£- ^> -J -4- »A \0 Oi co co -^OOOOOOOOOO
H H rl rl rI r—I r-f i—j rH f—I jH
OOHOO>AN«I^CJN OOi tO O%0 Oi HU"\D~t0E"-O?r\->tOOOGOC«<rOr-l H CM Oi H H r-3 H
kg V W 9 W V W
to C^ to -4" wr\ ir\ ir\
ft
I
pa ft
II
Oi3
OOOOO *AOiA,OV\OOOO^T»C^OivOHHOHOOr-'^i-OiCOtQOOi O^OvOCV O^tO -df to to kA'J-^OvOOiHHHCNiHr-IHr-trHHrHrHH
cvoiH
QV'sO Oi OO On. CO £*»•4 »A SA *A co =4 OiO^-^tQO^tOHtOOO^H
5- g> O Oi irvc^i>^'<i'-<t4rv»£>C\ir^c^^OOHrHOOOOOOOOOOOOooo«&o«oe<»oooo9»oooooooooooooooo
%vOtOOOtOOOHOiOHQtOOiO^O<TNOvOO'vOtOiHJr\Ql^Cf\^0-4h iH5,-'^0OO^tOC-OtOtOI^ OtO^\OtOtO\OiTvoo«o««C4eoe<>*09«rHOOOOOOOHOOOOOOO
vO Oi Oi Q> H Oi iAO^tiO -^to-^HO ^^cor"^OOOito<ro»Acoiwr\0\co»AfO-.TOOOOOOOOOOOOOOOO
> v i -. .. u •. voooooei—IrHrHrHrHiHiHrHirHsHjHrHirHrHrHr-1
\OOiOir^BHCVif\^tO-4'tO'=4'HO-4,
>d-cAE>»^-ooc\icot,r\»A{n»A^c^uNf^«lfVHHrltn«MHH>tC,\NHm-4no!OOOOOOOOOOOOOOOOo«ooooaooowoo«oooooooooooooooooo
Pn
ir\HE^C\itOOH%DO%OS>OiA«NsO=vtO^ O "A. O -d- -*t Qs Oi %0 Oi >fr £*=• o^ h o^ oco co oi oi -J co oi Oi «\ -~t co oi m w\ co cooooooooooooooooo009900e«000«00«0oooooooooooooooo
co»A?*-O^HCOW\t*-0>.iH?OM\ €fr H TOOi CO CO
tf
Pn
CMt0<>%O^c^*n?r\a\ir\<r<\sOCM£«"-inu>QN-J, H->3-
O CM CO -4" CO O c^ Q\ <T\ E*- H lAHvOOCOH^O CAcr\ C^ CM CM H CN C> CM CM r-i -<t (T\ <T\ CM CM ^ -4 C^\ C^\ Oioooooooooooooooooooo
CO
Pi
ur\<DM»v0\0\0(nOHC>?,"«)Ot0«0if>C>«)H>sfH HHHH(M>O60!)lA»A(AUMnHHrlrHrl
• V 9 < b j 3 *> 3 e> k 3 v e o • a e <>
CVCVCVCVCN HHHHHHHHHHHHHHH
hiaco c> c- cm
<r\ r-i i-i \0 a t>o »rNt» h into, m-Kfro^^tONc^mf-c^o ,OOtOCOC-OtOtO ?> !*- O 60 CO CO CO O CO CO t> vO
d d d d d d d d d d d d d d d d d d d d
insAOOOC^iAOCV^-OOOir\CMCOir\HirvCMOr*-rr\£*-"*tCM
O CM O <\J O OO D» m c> h oirviA-4--4--4"-4-^t»«tc^rrNC^\crNC^coir<^CV cv CM CM H
O OO^CMOi-tHIVNC^OOi lAOOHvOvOO^cnHr^HC^CM^o^^HCMc^vor^vOolc^HirvCMinvtr^(<\CM cm sfcnc^cnoi ir\ ^t ^" tn o^ \0 vO uMTvsi'
83cq
o
H ^ H -^ CO H t© iA -^ \0 ^Tv O sO H ^fr J> CM CO *f\ CO
C-CMvOtn-sJ-sJ-tO-ftO•>^*4t^c^CM-4t^(t\c<^
HOi £>4c>>Ai>^0 N O »ACM-^r^CNCMCMO^cncnf^CM
H «r\c-c^vDOOPr\CMHHO<r\OQCQC>-a^HHH(MHO\cnNvOO\OOCnOH
~ cSovO^HCOvom-tfCMH H H H HCMO^OmHOCO^O^OCMCMHHHOMHHHr-lrH.-l.HH
rf
OtnONo o ocomOtOO C>Ot>«M»rlOM CN CM \Q
iA«\»r\if\»Ar^c^ncn^OOOOO(OtOtOfrtHHHHHHHHHHHHHHHOOOOOo o
CMcrj
vO \Q MDvOMD-^O^OvOMJvOvOvOMD^vO'^vOvOMJM)OOOOOOOOOOOOOOOOOOOOm ir\ int»C>ONOOHHHHHHHHHHHHHOOcm oi cv c^r^f^c^<^c^ir^r^<^c«Ac^<^c^c<^rrN(r\r^
.
—
\ t-i r-{ r-i r-i r—i !—{ r-i t—{ r-{ r-i t—\ j—{ r-i r-\ r-\ i—\ r^ r-\ r—\
-tfOO^OOHirHHir~i r~i r-i r-i >—i >~i f—{ t-i
r~i r-i r-i r-\ t—{ s~i s-i r-i
CM CM CM CM CM CM CM""^ "4 "4" "^" "^ "4 "*3"
H H iH] H H H s—
j
t—\ r-4 r-i t~i t—i t—i e—i
tOOOHHCMCMCMCMCMC^ffNC^C^r^r^r^CMHiHir\irvirsu>inu^^^^^u>^ir\ir\sr\iir\ir\ir\ir\if\
«Hsn^A^CJsHf^'nf>C>HrrNV>{>ONHtn«%?>*0,>
ifMAnrkiAiAvD^OvO^O^Or-^-C^-D^r^tiOtOtOtOOO
4.6
»ArH!>CVtX)0(HvDOvOi^-Oif\C\ivO->tvO0sOir\o»3--NfrocvvOcv ^tC-o^HOOcvc^vo^cvcv -sfrc^ cv c\i ir\-<f(r\cv u> ur, c^ c\ -4-ooooooooooooooooo
H iH H H HrHHOOOOOOOOO
HO
t^vflnO^O lf\rHC-CV lf\ CO 0°. IT\ CV lT\COvO<>coto?>-<>cocoi>ONCOi>c^cocoi>vOco
v # % i * • i 6 o o o e t 'J fc B -3OOOOOOOOOOOOOOOOO
o*eo««eeooottoo« 0%
CMP0=1
j>cf\cv^«r\O-4'««tE^t0'sfiHvni -4-c\i<J-(C\J\ a\^ir\vOef\orr\NHiAOj>Ai>.OvOt»\0e«eoeoetaooao99ceo
-4r^rfNC\iv£> >*fr -^ <r\ CO !>• vr> -^J- CO CO \Q -<J-vO
CMsOCMC\lH»tf^£-Es-COO'>>.s0OtOmC\lH'. 3 „ j j c i c 3 * o a o o o »
\OO^p\fr\»Ti(>^HOO(^HvO"<tWt»\0
oPL,
CO
irM^OC>-~<it-E«->COC-HCVOCOCOH<VON^frOn CO C^- CO -<f E> CO r-i o^
HHiHMr-iHr-lrHfHQM^H^ UA OA C\ZO^WHOtOW
2°•4\flC0O ^KAO ^t4?vD H CO *P.O c^-^OrHOvrvHr-c^txa'rNOvDf^vOt-ic^c^oIinO HHOJ £- to CO gNWPvtrvvDv^ -4- -4- ^f vr. vr,HHHrHOOOOOOOOOOOOO
OOOOOOOOOOOOOOOOOcocpcocpcocpcpcpcpcocococococococpCVCVCVCViOiCviCVCVOi C\t CV C\i CV Oi Oi CM
1—Ir-Ir-li—IrHi—li—li—ir-IrHrHsHiHrHiHrHrH
r—li—lr-li—IrlHrldHrlHrlrlrIf—I H HHHHHHHr-lHrHHrHHHr-iHr-IH
HHHHriNNNHHOOOOOOri
OdHHHHHW(VC\iWW<n(*\N
- 47
APPENDIX D
SAMPLE CALCULATION
Run #51
Nozzle 0.05
Pa 30.09 "Hg
1, Calculation of Scavenging ratic (Rs )
a. Using the Leary and Tsai orifice analysis
^ =(Mchart) Jj(
Pa 5^°x ^ (I)
30.00 T
f°r Mchart see f±S^re VI11
for Y see figure EC
v = (n^o^ P ' 1 * 3° ?09 * ^j§ * 0.992 = 0.1596Ma m (0,1128) / 30.00 538
Ma = 0-1596 #/gec
b. p = QJk.fg
NV.R«
=^HJV
N ~ 12°° ^s c
V = 0.0435 ft3o
PEf* W7~ PE=34c29"Hg
T„ = 538 R
B .60M* = 1.15 i-Rs 1200 x 0,04.35 f s
0.491 x PE x 144= x 328 ^^3 * 53.3 T
5' T,
R = 1.15 x 0.1596 m 2 ,
0.0846
48 -
Figure VIII
i
I<0
II
I
II<*)T
\ K JJ
1
& ^J
SC*
NV
J
j
ft ^r '
$3
— -
-<!
Vi55
—
—
^
w»}
* ^ ^ 5Q
$ $q
5*
I
- 49
Figure IX
1
Ps to
*
X
is^
i
\
1
J
i
t
E
i
I
<5
<]<*•
S3
~
-
1V
c
c
5 ^c
c
\
\
<
c
c \
i
<V
- 50
Figure X
Si
aSi Si Si
^ >4
£ £k
& 5^
>
^ ^^
1 U) s\ ^
1 sI
^ t H;—J
^ u <0
<0<0 V
\-
CO
SJ
R <0Si
s>
52
ss
5^
5-
51
\V
s,
0\
Si
>0
s;
w>
*
- 51
Figure II
is! * 51
i
(ops/,
8?
!<
1
0:
1O
NO
1
\*) *h/ 'mo,7y 7^/V
\
t 3 ^ 1^ ^ ^ ^Q S$ SS "^
- 5 2 -
2. Calculation of the fuel-air ratio (F)
a. Entering figure X with Rs = 2.17 :
b. V-2*. - 0*22 . 0.424 *f= °- 00265 lb/sec
Rs 2.17 ^ = 0.1596 lb/sec
c. F= St- ,= 0.00265
Ma 0.424 x 0.1596
F - 0.0392
3» Calculation of Brake mean effective pressure (BMEP)
a. Dynamometer BMEPj^
From evaluation of dynamometer system
BMEPM = 5.62 (Brake load)
B.L. - 15.7 nHg
BMEPm - 5.62 x 15.7 - 88.3 psi
b. IMEP was determined from indicator card
IMEP = 286 psi
c. Determination of friction mean effective pressure
FMEP = IMEP - BMEPM
FMEP - 286 - 88.3 - 197.7 psi
However since the FMEP so determined was the total friction mean
effective pressure for 3 cylinders
FMEPC = iSZil = 65 e9 psi ( for one cylinder)
d. Corrected value of BMEP
BMEPC = 286 - 65.9 = 220.1 psi
- 53 -
4. Determination of the Pinkel factors for correlation of data with
reference (5)
Mp = Ma-+ Mj, = 0.1596 4 0.00265 =* 0.1623 lb/sec
PT = 14.88 psi
AN = 0.05 Ap
Ieo = 32.2 a; 5.55 T= Reading on manometer
Mj. 0.1623 2
u = 1037.0 ft/sec
TE = 968°R
aE = 49 /te = 49 t^68 = 1521 ft/sec
u/aE - 1PJZ = 0.6801521
b ^N go _ 14.88 x 0.05 x 14.15 x 32.2D
* MpAg 144 0.1623 x 1521
T - 2° = 5o55
PtAn £2 = 1.37
5. Determination of Thrust and IMEP relationships
It was attempted to correlate thrust as measured on the force plate to
engine IMEP by the following dimensionless coefficients.
T eo MET * Ap x g0
Mpag tap x aE
T 5*55 lbs
^ - 0,1623 lb/sec
aE= 1521 ft/sec
IMEP = 286 psi
- 54
Mj,aE 0,1623 x 1521
0.680Mj.
•E
bIMEP x Ap x go ^ 286 x 14.15 x 32.2
Mp x aE 0.1623 x 1521
6. Determination of TMEP and IMEP relationships
a. An analysis of the blowdown turbine process leads to the follow-
ing expression
TMEP = 1±_X 9 / u2 j? kbIMEP Q^'i ) 2goJ p
b. F s (overall fuel-air ratio) =/"*F
F 8 - 0.4.24 x 0.0392 » 0.0166
Qc - 18,500 BTU/lb
J = 778 ft Ib/BTU
~0 kb= 0*75 (from NACA technical data)
">? i - 0.4j6 reference (ll)
3?kb . 0»75 __ = 1 ,
Q-7n'2„ J O.46 x 18 S 500 x 2 x 32.2 x 778 568 x 105^cyL go *
It follows that
„ BK - 1 , /W x u2 ?
IMEP 568 x 105 / F» J
TMEPIMEP
3^I£ = 0.112IMEP
1^66 x 15212/>
TMEP 4; IMEP _ 1-v 0.112 -i 11PIMEP 1
*
TMEP - 0.112(286) » 32.0 psi
- 55 -
7o Determination of thrust and brake horsepower relations
c= i,iL BMEPr - 0.2135 BMEP
5o62
BMEPC « 220.1 psi
BHP » 0.2135 (220.B) = 47.1 hp
bo Thrust and brake horsepower are correlated on the basis of
the following dimensionless coefficients?
Pgo .
Ma2 '
T
Mav
Rs
and F .
c. Calculation of TP gom
Ma2and
Tgo
Ma
T, as 538°R
a = 49 /T^ = 49 i^38 - 1134 ft/sec
a2 = (1.134 x lO?)2 - 1.285 x 1C>6 ft2/Sec2
^ - 0.1596 lb/sec
TP = 47.1 hp
^r ,1q782 x AaiaJL x 10"2 = 4ol00.1596 x 1.285
S2? - 4ol0
T
Ma
F -
R« =
x 32.20.1596 x 1134
0.0392
2.17
= 0.988
- 56
APPENDIX E
ENGINE FRICTION
Measurements of dynamometer brake load were made while running the
engine under the various load operating conditions „ AlsOj, for each test
run at these conditions^ a pressure-time indicator diagram was taken using
the MIT high speed pressure indicator apparatus » This diagram was further
translated into a p-v indicator card for the determination of indicated
mean effective pressure (3MEP) of the single cylinder.
Using this IMEP and the overall brake MEP determined from the
brake load measurement^ a value of overall friction MEP was obtained
from IMEP - BMEPM= FMEP 5 This overall FMEP was then divided by three
to obtain approximately the single cylinder FMEP„ By plotting these
values of FMEP versus IMEP;, no definite conclusions could be established
in regard to correlations of same nozzle area,, constant scavenge ratio,,
or fuel-air ratio, A qualitative mean line was established for compara-
tive purposes = See figure XII.
It follows that the single cylinder BMEP may be determined from
IMEP„ - FMEP =BMEPrt .
v c c
57
Figure XII
V
^ 00
§
tf—
a
\
1
1>4
Cfc$. or * 5 m Si
i
••
CO>
v6 £> ^
£ > 5
k~ ^ *
a as•
1
1 5^ ,
V *°
•i
1co » • O
1•
c ) \ o
t• • •
oV •
o •
d
c
• \ °
•
fl
•
3 r\
o \
\ °
• < >
# \ °
o
\*2 S Y> ^ *o Q &
d3!/U1 —
.
—.
.... j
53
APPENDH F
BIBLIOGRAPHT
1„ Parsons, T„M and A Zang, Measurement of the Available Energyin the Exhaust Gas of a Diesel Engine VJith Regard to Turbo-charg-ing Application; BS Thesis, MIT Library, May 1952„
2 Crowley, JJ)o, A CW Gottschalk, W eRo Nodell, The Utilization ofExhaust Gas Energy of a Two-stroke Diesel Engine; NavE Thesis
,
MIT Library , May 1957c
3o Taylor , C CF et al, Loop Scavenging vs* Through Scavenging ofthe Two-cycle Engine; SAE Paper #247 presented at the SAE NationalDiesel Engine Meeting, Cleveland , Ohio, Nov 5-6 s 1957
,
4. Leary, W cA e and D H e Tsai, Metering of Gases by means of ASMESquare Edge Orifice with Flange Taps
5» Pinkel, B,, Utilization of Exhaust Gas of Aircraft Engines;Tran SAE ^ (1946)714.
6o Smithy HeToj, Turbocharging the Two-stroke Diesel Engine; SAEJournal 6jJ (June 1955) 75
o
7. Chamberlain, oA o and G H Bollman, Turbocharging Two-stroke GasEngines; ASME (CGP Division) Proceedings 26th Conference , June1954o
8„ Livengood, J<,C and J<J)<, Stanitz, The Effect of Inlet-valve Design^Size, and Lift on the Air Capacity and Output of a Four-strokeEngine; NACA TN915, 1943.
9« Turner, L SR» and R»N, Noyes, Performance of Composite EngineConsisting of Reciprocating Engine(Sl), Blowdown Turbine andSteady-flow Turbine; NACA TN1447> 1947
.
10. Schweitzer , P H and T C o Tsu, Energy in the Engine Exhaust; ASMETrans, vol. 71, no 6 (1949)
•
llo Class Notes, Course 2<797, MIT
- 59
thesW67
Development of a des•On parameter for th
3 2768 001 90017 8- n " DI-EYKNOx l.BRAry
;'•..
i 1 ' ' ' ;
1 1'
ri '
' '
[ ' 1 Vii i '1 ' t » • M '' U t it [riitjl ' ?' 1 1 1 lltl t\)[w\Vli\{\l till tilt ittrllllTlittttm
-'''" l
11Irftff'fUZ
''
' It]:
'
iitiiltnii'
• ' tit]
fi[|
,l
'iiii[ i*''
'
!
' ' ^ ''
'
1
-•
.
*
' i ' i
'
lllfrft
I
