1

Lecture 8: Environmental Emissions

Eric Loth

For AE 440 A/C LectureSept 2009

2

Some Emissions Responsibilities

a. Identify emission sources (acoustical, chemical and particulate) for flight & operations

b. Develop concepts to reduce emissions

c. Develop quantitative analysis for sources

d. Develop schemes to quantitatively minimize emissions (AE 441)

3

Acoustic Emissions

Reference: Aeroacoustics of Flight Vehicles, Vol. 1 and 2, 1995, H.H. Hubbard (on reserve)

4

Prop Engines

5

Turbo-Fan and Airframe Noise

2 6

4

sin V SOASPL in dB 10log 28.0

r AR

2 6

4

sin V SOASPL in dB 10log 28.0

r AR

t inlet

Peak OASPL in dB

T40log 20log U 10log A 164

T

2 6wing

4

OASPL in dB

V Ssin10log 28.0

r AR

6

Time vs. Spectra & A-Weighted Spectra

7

Cabin Treatment (Near-field)

8

Flyover Footprint (Far-Field)

9

Suggestions for Noise Emissionsfor CDR

• Review FAA Limits and determine Team Design noise constraints

• Examine noise levels of various engines (impacts Propulsion choice)

• Examine noise levels of various airframes

(impacts Aerodynamics choice)• Consider noise mitigation strategies• Investigate techniques to quantify noise levels

10

Particulate and Chemical Emissions from Aircraft Engines

11

Particulate Emissions

12

Particulate Impact on Health

13

Particulate Flux by Engine

http://www.trbav030.org/pdf/TRB05Ann_685_j_pehrson.pdf

14

Particulate Flux by Aircraft

15

Particulate Flux by Fuel

16

Suggestions for Chemical and Particulate Emissions

• Review FAA Limits and determine Team design emission constraints

• Examine emissions of various fuels and engines (impacts Propulsion choice)

• Consider mitigation strategies for soot and chemical species

• Investigate techniques to quantify chemical and particulate emissions