Achieving an Improved Understanding of the Factors Affecting an Aircraft Environmental Control System by Coupling a 1D Cabin Air Distribution System Model with a 3D Passenger Cabin Model using Co-Simulation Middleware 2009-01-3264

Aircraft Environmental Control Systems (ECS) are designed to optimize passenger comfort by providing satisfactory cabin pressurization, and temperature and humidity control whilst minimising the risks to passenger health from airborne toxins and diseases.

The paper presents a case study that investigates how the cooling load discharge from an ECS system affects the flow behaviour inside a typical mid-size, wide-body aircraft passenger cabin. The investigation uses commercial off-the-shelf one dimensional (1D) Computational Fluid Dynamics (CFD) software to model the cooling pack, cabin air distribution system, and three quarters of the passenger cabin. The centre section of the cabin is modelled using a commercial off-the-shelf three dimensional (3D) CFD package, with the co-simulation middleware providing coupling adapters to ensure that two-way, bilateral exchange of boundary parameters between the 1D and the 3D CFD models gives continuity of mass and momentum transfer. The 1D and 3D CFD applications and Co-simulation middleware are supplied by 3 independent commercial organisations.

The results of the case study are discussed including the co-simulated ‘velocity field of the air discharge’ and the ‘temperature gradient inside the cabin’ within the 3D CFD model as well as the flow and temperature fields within the one-dimensional ECS cooling pack model. The paper concludes by discussing how the proper implementation of the co-simulation methods developed in this case study could bring significant benefits to engineering companies using CFD tools, including improved quality of simulation results and reduced simulation run times.