The impact of wind turbulence on the precision of a numerical modelling study.

The aim of this study is to illustrate the importance of the effects of wind turbulence on airchange in buildings. Using two simple configurations, tested over a short period, twoapproaches are compared.The tests are performed using m experimental house which is filly exposed to the wind. Theair flow rate is measured over 15 minutes for two configurations: natural ventilation via twoopenings positioned on two opposing facades, and mechanical exhaust ventilation with twonatural air openings.A code simulates this phenomenon using three numerical solutions based on the frequency ofwind-related measurements:- use of the experimental meteorological file,- average of the experimental meteorological file at a fi-equency of 1 Hz,- average of the experimental meteorological file in order to obtain one value.The simulation with the one-value file reduces the rate of real air change by around 20%. Theother two simulations offer greater precision: less than 2% for the natural ventilationconfiguration and around 6% for the mechanical ventilation one.This study demonstrates the importance of the effects of wind turbulence. Where numericalmodeling is concerned, it would appear necessary to take into account the wind fluctuationsrelated to turbulence in the field of high frequencies.