Final Project - MSc in Automotive Engineering

Tiago Carvalho

Technological evolution in the past years led to a higher energy consumption

A higher energy consumption led to a larger environmental pollution and consumption of natural resources

The contribution of Transports towards the total final energy consumption in the EU reached a

value of 31.7% in 2010

Governments applied laws and regulations to reduce the pollution emissions derived from

vehicles

The automotive industry has been increasing the investment on research & development of new solutions for the reduction of fuel consumption

and pollutant emissions

INTERREG’s CEREEV Project investigates the concepts of IC engines in order to improve the efficiency of a small hybrid electric vehicle

Studied possibility of using a split-cycle engine with hybrid vehicle

How to improve air intake in a rapid charge engine?

Injection of air in combustion chamber

CEREEV engine: 80mm diameter and 500rpm

Injection of air in cross-flow of air:

1

2 1 – Cross-flow

2 – Injection flow

Duct Injector

Theoretical calculations of hydrodynamic entrance region inside the duct:

Lh > ~ 2500mm

Hydrodynamic entrance length is bigger than wind tunnel working section

Duct used:

◦ Rectangular profile

◦ Metal and polypropylene sections

◦ Straighteners located at the metal section’s entrance

Results at 430rpm wind tunnel fan speed:

-80

-60

-40

-20

0

20

40

60

0 2 4 6 8 10 12 14

Vert

ical p

osit

ion in d

uct

(mm

)

Cross-flow velocity - U component (m/s)

Velocity profile at duct's exit - Comparison Pitot tube vs. PIV

PIV - End of duct Pitot tube - Entrance of duct

Pitot tube - Middle of duct Pitot tube - End of duct

Static injection at different ASOI with 4bar injection

ASOI = Advance Start Of Injection (relative to the first PIV laser pulse)

Injector

Results at 4bar and -500μs ASOI:

Injector

Vertical penetration

Angle of injection

CVP Formation

Experiment was done with 4 different ASOI and 4 different cross-flow speeds

Images were post-processed using the Adaptive PIV method

Vector field results:

Display options were altered to observe the alterations in the U and V components of the flow’s velocity

The U (horizontal) component is displayed with a contour plot. The V (vertical) component is displayed with vertical blue vectors

Contour plot results:

Vector fields obtained at -500μs:

2m/s 5m/s 7m/s 10m/s

Contour plots obtained at -500μs:

2m/s 5m/s 7m/s 10m/s

The results obtained at -500μs:

Cross-flow speed

Static 2m/s 5m/s 7m/s 10m/s

Vertical penetration

(mm) 19 16 13 11 11

Speed of injection (m/s) 18 21 22 22 23

Angle of injection (o) 42 44 49 54 55

Cross-flow speed

2m/s 5m/s 7m/s 10m/s

Max |U| (m/s) 36 41 45 44

Max |V| (m/s) 38 47 36 39

Purpose of experiment was to investigate the injection of air into combustion chamber of a rapid charge IC engine

Model consisted of injecting compressed nitrogen in a duct with a cross-flow of air. PIV optical technique was used to analyse the results

The results showed: ◦ CVP are formed with the injection of compressed

nitrogen in air

◦ Increase in the cross-flow speed affects the profile of the injection

Increasing the cross-flow speed will:

Increase Decrease Maintain

Angle of injection (horizontal penetration)

Injection’s vertical penetration

Maximum V component of the flow

Maximum U component of the flow

CVP formation and intensity

1. Use compressed air instead of nitrogen

2. Different seeding process through the injector

3. Variable pressure instead of constant

4. Study injector’s internal dimensions and determine mass flow injected

5. Impact of different injection angles

6. 3D optical method for analysing the entire injection’s hollow cone

7. CFD analysis and in-cylinder experimentation

THANK YOU