A Simplified Approach for Quantifying Driving Rain on Buildings PDF

A simplified approach for quantifying driving rain loads on building facades is presented. It is based on the well-known semiempirical driving rain relationship (driving rain intensity = coefficient * wind speed * horizontal rainfall intensity). The coefficient in this relationship has often been assumed constant, but in reality it is a complicated function. For use in the simplified approach, this coefficient—as a function of building geometry, wind speed, wind direction, horizontal rainfall intensity— will be determined in advance by a set of numerical simulations with CFD (computational fluid dynamics). The resulting catalog with driving rain coefficients is then made available to users, and the simplified quantification approach consists of using these coefficients in combination with the driving rain relationship and standard weather data (wind speed, wind direction, horizontal rainfall intensity). In this paper, the philosophy of the simplified quantification approach is presented and illustrated for the case of a low-rise building.