The Research Of Coupling The Environmental Control System With Air Thermal Environment In An Aircraft Cabin

With the development of the aviation business,the improvement of people’ living standards and the speeding up of globalization,more and more people choose plane as the tool for traveling.The cabin thermal environment is closely related with the passengers’ safety,health and comfort.The cabin thermal environment is influenced by the change of the external environment,aircraft environmental control system and the heat dissipation of cabin interior equipment and passengers.In general,the heat dissipation is fixed but the external environment changes a lot.One is the initial air temperature in aircraft cabin is very low or high in a cold winter morning or a hot summer afternoon which does not meet the requirements of the human body thermal comfort.Another is the aircraft experiences rapidly changes in outside air temperature in the flight process.These changes of the external conditions will have huge effects on the cabin thermal environment thus aircraft environmental control system need to change the condition of the supply air to guarantee cabin thermal environment in a suitable condition.Meanwhile,the changes of the cabin thermal environment will affect the regulation of the aircraft environmental control system.Therefore,the research of the interrelation between the cabin thermal environment and environmental control system in such situations is necessary in order to create a good and suitable cabin thermal environment and to optimize the aircraft environmental control system.Experimental measurement and numerical simulation are two major methods to study the aircraft environmental control system and cabin thermal environment.The real and reliable data would be obtained by the experimental measurement but the cost and the manpower would be high.The method of numerical simulation was more and more popular due to the advantage of low cost and the detailed information would be provided.However,the correctness and accuracy of the numerical simulation should be validated before.Thereby this research adopts the experimental measurement and numerical simulation methods both.Firstly,we studied the interrelation of the aircraft environmental control system and cabin thermal environment by experimental measuring in a real MD82 aircraft on ground condition with the ground air condition cart being on in cold winter morning and hot summer afternoon,respectively.Then we set up the models of the aircraft environmental control system by Simplorer software and cabin environment model by Fluent software and coupled them to simulate the cabin environment to validate the correctness and accuracy by comparing with the experimental data.Finally,the validated models were applied to study the interrelation of the aircraft environmental control system and the cabin environment in flight conditions.The experimental results showed the vertical temperature variation was obvious in heating process in winter but the temperature distribution was uniform in cooling process in summer,when using the ground air condition cart to control the cabin thermal environment on ground condition.The simulation results of coupled the aircraft environmental control system model in Simplorer and the cabin thermal environment model in Fluent agreed well with the experimental data thus the correctness and accuracy of the coupled model was validated.Then the coupled models were adopted to study the interrelation of the aircraft environmental control system and the cabin environment in flight conditions.The coupled simulation results in flight process showed the air temperature distribution was very uniform which met the ASHRAE Standard under the regulation of the aircraft environmental control system thus the thermal comfort was guaranteed.Therefore,the coupled models and the coupled methods in this study can be used in the correlational researches of the aircraft environmental control system and the cabin thermal environment.