Dynamic CFD Modelling of Thermal Mass and Air Movement

Recent work has begun to consider the potential for using freeze flow techniques in Computational Fluid Dynamics programs for carrying out long term simulations of time dependent flows. This paper describes and tests a new, adaptive control method which automatically adjusts the lengths of the frozen and unfrozen flow periods in the solution procedure, based on current and imminent conditions. The adaptive control method demonstrates improved performance compared with an invariable control method. Tests using the new method for different flow scenarios have shown good agreement with the results obtained using a traditional fully transient CFD simulation in which all equations are solved without interruption. Simulation CPU time and data storage requirements were reduced by up to 88% and 70% respectively when compared with a fully transient CFD simulation.