Research On Emission Reduction In Aircraft Approach Phase Using Time-Based Separation

In recent years,with the increase of carbon emissions,global climate change has had an increasing impact on human production and life.As one of the sources of global greenhouse gas emissions,the aviation transportation industry is actively taking measures to reduce aviation emissions.Reducing aircraft flight time is an important means of reducing aviation emissions.This thesis studies the purpose of reducing aircraft flight time during the final approach phase to achieve emission reduction.Aircrafts need to be equipped with a reasonable wake separation during the final approach phase,and the current implementation of radar control at busy airports during the final approach phase is carried out according to the distance separation,but under high headwind conditions,aircraft ground speed is relatively small,leading to an increase in the landing time separation between two aircrafts,resulting in increased fuel consumption and pollutant emissions.Therefore,this thesis introduces a time-based wake separation to reduce the flight time of aircraft in the final approach phase under high headwind conditions,and to reduce the fuel consumption and pollutant emissions of aircraft while ensuring operational safety and operational efficiency.Firstly,the domestic and international wake separation criteria are sorted out and analyzed,the wake characteristics and evolution mechanism of the final approach phase are studied,and the maximum safe circulation that the follower aircraft can withstand is studied in combination with the ultimate roll moment coefficient that the follower aircraft can withstand;the influence of the headwind on the wake evolution is analyzed based on the data detected by Li DAR,and the results show that the headwind accelerates the wake vortex decay of the leader aircraft;the safe circulation that the follower aircraft can withstand,the distance-based separation criteria and runway occupation time,a time-based wake separation calculation model is established.Secondly,based on the LTO(landing and take-off)cycle emission inventory published by ICAO and the aircraft performance database(BADA,Base of Aircraft Data),the fuel flow and pollutant emission index were modified by using the parameter correction method,taking into account the meteorological factors and combining with the airport meteorological report data.The final approach process of B738 at Qingdao Jiaodong Airport is used as an example to discuss the changes of fuel consumption and pollutant HC,CO and NOx emissions with temperature,barometric pressure and wind speed.Temperature,air pressure and wind speed are closely related to fuel consumption and pollutant emissions,and the effect of wind speed on pollutant emissions is very significant.Then,based on the time separation operation mode,the study of fuel saving and emission reduction in the final approach phase of aircraft was carried out.Based on the actual meteorological data and operation data of Qingdao Jiaodong Airport,the fuel consumption and pollutant emission of incoming aircraft under five different headwind sections were calculated.The fuel consumption and pollutant emissions of HC,CO and NOx are significantly lower than those of distance-based operation mode under 0-27 kt headwind speed,and the fuel saving and emission reduction rate increases with the increase of headwind speed,reaching 38% at maximum.Finally,a time-based separation emission reduction calculation and analysis software based on MATLAB was developed to calculate the minimum time-based separation and aircraft fuel saving and emission reduction efficiency in the final approach phase to provide reference for actual operation.