LES and RANS Simulation of Turbulent Airflow and Tracer Gas Injection in a Generic Aircraft Cabin Model

This study is a continuation of a previous research in numerical simulation of a turbulent airflow in a generic aircraft cabin model. Specifically, the primary objective of this project is to use Computational Fluid Dynamics (CFD) to simulate transport of a tracer gas injected into the generic aircraft cabin. The research work reported herein is composed of three parts. First, both Large Eddy Simulation (LES) and Reynolds averaged Navier Stokes (RANS) methods are used to simulate airflow from a full-height nozzle and corresponding airflow characteristics within the mockup aircraft cabin. The computational results are validated by comparing them with Particle Image Velocity (PIV) data and published CFD predictions available in the literature. Through these comparisons, the potential for using the CFD methods to predict unsteady as well as time-averaged velocity for a generic aircraft cabin model is examined. Second, airflow characteristics are studied by reducing the inlet nozzle height to one-half of its original size but keeping the total volumetric airflow rate the same as that of the full-height nozzle. Accuracy of the LES approach in predicting airflow in the half-height nozzle is evaluated by comparing prediction results with the PIV measurement data for the mockup cabin. Third, simulation of a tracer gas injection through the injecting tube placed in different locations in the half-height nozzle cabin is investigated. In this part, carbon dioxide (CO₂) is chosen as the tracer gas. The LES method is used to solve the equations of motion and the unsteady species transport equation for tracer gas concentration. The predictions are compared with the average measurement data for CO₂-concentration in various locations in the cabin.