Simulating wind-driven rain on building facades using Eulerian multiphase with standard k - epsilon turbulence model

Abstract

Wind-driven rain (WDR) is responsible for many types of damage to building facades and contributes to runoff management problems in urban environments. Consequently there is significant interest in predicting WDR using CFD simulations. In this thesis an Eulerian multiphase (EM) method is proposed which includes solving the rain phase closure equations instead of using a response coefficient to approximate turbulent behavior. The simulations are conducted using AVL FIRE with standard k - epsilon model and are validated against experimental data. The method produces results with error ranging from 1% to 50%, comparable to previous methods. In addition the use of no-slip boundary conditions on the facade walls causes artificially high levels of WDR, requiring numerical or methodological compensation.