2015-08-21
300
Emissions of passenger aircraft per passenger kilometre vary extensively, according to variables such as the size of the aircraft, the number of passengers on board, and the altitude and distance of the journey (the practical effect of emissions at high altitudes may be greater than those of emissions at low altitudes).
This is similar to the emissions from a four-seat car with one person on board.
Per passenger kilometre, figures from British Airways suggest carbon dioxide emissions of 0.1 kg for large jet airliners (a figure which does not account for the production of other pollutants or condensation trails).
In attempting to aggregate and quantify the climate impact of aircraft emissions the Intergovernmental Panel on Climate Change (IPCC) has estimated that aviation’s total climate impact is some 2-4 times that of its CO2 emissions alone (excluding the potential impact of cirrus cloud enhancement). This is measured as radiative forcing. While there is uncertainty about the exact level of impact of NOx and water vapour, governments have accepted the broad scientific view that they do have an effect. Accordingly, more recent UK government policy statements have stressed the need for aviation to address its total climate change impacts and not simply the impact of CO2.
Exercise 7. Have a look at the following translation. It contains a number of mistakes and inaccuracies. Act as a proof-reader and rewrite the sentences in accordance with the rules of style, grammar and word combinability.
| Much of the noise in propeller aircraft comes equally from the propellers and aerodynamics. Helicopter noise is aerodynamically induced noise from the main and tail rotors and mechanically induced noise from the main gearbox and various transmission chains. The mechanical sources produce narrow band high intensity peaks relating to the rotational speed and movement of the moving parts. In computer modelling terms noise from a moving aircraft can be treated as a line source. Aircraft Gas Turbine engines (Jet Engines) are responsible for much of the aircraft noise during takeoff and climb. However, with advances in noise reduction technologies – the airframe is typically more noisy during landing. | Більшість шуму в пропелерному літаку походить однаково з пропелерів та від аеродинаміки. Гелікоптерний шум спричиняється аеродинамикою з основного та хвостового ротора та механічно спричиняється шум з основної коробки передач та різних ланцюгів передач. Механічні джерела виробляють вузькополосні високоінтенсивні піки, що відносяться до ротаціної швидкості та руху рухомих частин. В компютерному моделюванні терміну шуму з рухомого літака може розглядатися як лінійне джерело. Газотурбінний двигун літака відповідальний за більшість шуму літака під час зльоту та набору висоти. Однак з розвитком у зменшенні шуму технологій літальна рама зазвичай більш шумна під час приземлення. |
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