Calculation Of Transient Heat Load For Aircraft Cabins

In order to protect the aircraft occupant feeling comfortable and the instrumentation to go reliable, as well as to save energy, the steady-state and transient heat load should be calculated accurately in the design stage. However, the open literatures on the study of transient heat load for aircraft cabins were very few at home and abroad. And there was no one can supply the engineering application of the calculation of transient heat load for airliners. This situation was extremely detrimental to research and produce the airliner Environmental Control System. So, the following studies were carried out in this paper:1. The literatures on the calculation of transient heat load for aircraft cabins at home and abroad were researched, and the method of numerical computation to calculate transient heat load for airliner cabins was determined.2. Using ARJ21-700 as a numerical example, the pressurized areas of the aircraft were parted and based on the heat transfer model to solve the transient temperature field by using the finite difference method. The transient heat load and air temperature distribution for cabins under the ground downtime were obtained, as wall as the changes over time about the transient heat load for aircraft cabins during flight. And the transient heat transfer for cabins of the machine model and the single compartment model was compared.3. The influence of the insulation performance of the aircraft about the material layer layout, thickness of the air sandwich, the location and thickness of the insulation were researched.4. The heat transfer for the three non-transparent envelopes, that is one-dimensional four-story structure, equivalent one-dimensional single-layer structure and two-dimensional structure, was compared.Studies show that: The gas volume in cabins had more effect on the heat transfer of cabins under the ground downtime. The range of the thermal load for cabins was larger during flight. And the calculations of the transient heat transfer about the whole machine and the single compartment were different. Besides, the influence of the insulation performance of the aircraft about the material layer layout, thickness of the air sandwich, the location and thickness of the insulation was smaller. But the influence of the heat transfer of cabin envelopes about the compartment boxes and stringers was larger. Studies all above provided an important foundation for the selection of the aircraft environmental control system, optimization of parameters and the study of control laws.