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Intro to Aeronautics > Environmental Impact of Aviation > Flashcards

Environmental Impact of Aviation Flashcards

1
Q

sound waves

A

oscillations of the air that can be heard by human ear or measured by physical device

progresses as a periodic oscillation of the air density through longitudinal waves

characterized by a local speed of sound and local sound pressure

amplitude is loudness

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2
Q

sound pressure level

A

reference 2*10^-5 Pa

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3
Q

sound intensity

A

quantitative physical metric to address the energy transport of a sound wave

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4
Q

noise

A

subjective evaluation of the degree of annoyance of sound

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5
Q

current maximum levels

A

perceived noise level (PNL) measure of the current noise level determined by empirical weighting of the intensities of multiple frequency bands relative to the overall noise level

tone corrected perceived noise level (PNLT): addition of tone correction for tone noise in the frequency spectrum

a-weighted sound pressure level (La): evaluation of the current noise level according to the A-weighting curve

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6
Q

maximum level for one event

A

effective perceived noise level (EPNL): measure of the noise level taking into account the chronological sequence of a sound event.

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7
Q

sound exposure level (SEL)

A

same as EPNL but without tone correction and taking the A-weighted sound pressure level as a basis

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8
Q

level for multiple events

A

weighted equivalent continuous perceived noise level (WECPNL): measure of annoyance of noise at an airport through the integration of measured EPNL during one year

energy equivalent constant sound pressure (Leq): measure of noise emission during one day on basis of SEL (europe)

day-night level (DNL): measure of noise emission during one day on basis on the SEL (america)

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9
Q

positioning for noise certifications

A

approach (2k from runway threshold under approach flight path)

sideline (highest noise measurement recorded at any point 450m from the runway axis during takeoff)

fly-over (6.5 km from the brake release point under the takeoff flight path)

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10
Q

ICAO noise regulations ch 14

A

increase in stringency of 7 EPNdB relative to chapter 4

applicable to new types submitted for certification on or after 31 december 2017

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11
Q

source of sounds

A

engine noise during takeoff structure noise during landing

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12
Q

noise mitigation short term

A

experimental methods aimed at optimizing the noise characteristics of landing gear and high lift devices

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13
Q

noise mitigation long term

A

calculation of noise emissions and local distribution through CAA (computational aeroacoustics), noise focused optimization through numerical simulation of various configurations

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14
Q

night curfews

A

predominant at european airports, one runway closed, max noise levels

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15
Q

limitation of noise level

A

flying ban / penalty charges when a certain noise level is exceeded

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16
Q

quota regulations

A

max number of flights per airline/time interval according to noise

17
Q

noise charges

A

based on noise level, time of departure/arrival, and season

18
Q

noise reducing procedures

A

thrust cutback, steep approach/takeoff procedures

19
Q

emission index

A

indicate the quantity of a specific pollutant per kilogram of jet fuel burned

20
Q

ICAO landing and takeoff (LTO) cycle

A

local air quality emissions from MSL to 3000ft, emissions measurements are referenced to LTO cycle, simple estimation calculations, model cycle and does not capture pilot behavior

21
Q

ozone health

A

lung function impairment, effects on exercise performance, lung structure damage

22
Q

carbon monoxide health

A

cardiovascular effects

23
Q

nitrogen oxides health

A

lung irritation and lower resistance to respiratory functions

24
Q

particulate matter health

A

premature mortality, aggravation of respiratory and cardiovascular disease, lung function, lung tissue

25
Q

volatile organic compounds health

A

eye and respiratory tract irritation, headaches, dizziness, visual disorders, memory impairment

26
Q

ozone environment

A

crop damage, tree damage

27
Q

carbon monoxide environment

A

similar health effects on animals as on humans

28
Q

nitrogen oxides environment

A

acid rain, visibility, particle formation

29
Q

particulate matter environment

A

visibility, building soiling, safety for aircraft

30
Q

volatile organic compounds environment

A

contribution towards ozone formation, odors, buildings and plants

31
Q

means of environmental protection

A

ICAO annex 16 vol. 2 limits NOx, CO, HC, and soot

emissions depending landing fees

emission fees, environmental charge per passenger

CO2 compensation charges to passengers

european emissions trading system

kerosene tax

32
Q

ICAO annex 16 vol. 2 engine emission certification

A

applicable for all engines with a rated output exceeding 26.7 kN being produced after jan 1, 1983

referenced to MSL and ISA

mandatory requirement of all ICAO member states

33
Q

european emissions trading system (EUETS)

A

integrate commercial aviation into system from 2012

partially open (can by certificates from sectors other than aviation)

only CO2 emissions taken into account

aviation sector receives certificates representing 97% of average CO2 emissions produced yearly within 2004-2006, budget will be lowered to 95% from 2013 to 2020

34
Q

current state EUETS jan 2015

A

prices for certificates much lower than originally anticipated (almost no incentives for companies to lower emissions), only european domestic flights, waiting for ICAO to make international scheme

35
Q

reducing engine emissions

A

increase specific fuel consumption, combustion chambers with low NOx production, optimization of the joule-brayton process, alternative fuels

36
Q

intercooled recuperated core

A

intercooler located between low and high pressure compressor, use of exhaust heat exchanger, low overall pressure ratio (25)

advantages: very high thermal efficiency, low NOx, 30% fuel burn reduction, technological maturity expected 2035

challenges: integration of intercooler and exhaust recuperator, low pressure losses, light weight and reliable system parts

37
Q

reducing emissions design

A

aerodynamics reduce drag (blended winglets, advanced wing profiles, hybrid laminar flow control, adaptive wing)

structure reduce weight

configurations reduce weight and drag

38
Q

reducing emissions operations

A

optimized air traffic management, low emissions terminal procedures, low emissions airport operations

39
Q

greener by design

A

increase L/D, wing span up, wing weight up

radical approaches: blended wing body, natural laminar flow control, hybrid laminar flow control, full laminar flow control

Intro to Aeronautics (8 decks)

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