An approach of calculation and analysis of pulsating flow rate of single-sided ventilation due to unsteady wind pressure

Abstract

Natural ventilation of buildings has received considerable attention aiming to reduce the energy consumption and CO2 emissions. The flow rate of a single-sided ventilation building due to unsteady wind pressure consists of two elements: mean ventilation rate and fluctuating ventilation rate. To design an efficient ventilation system, an accurate model that is capable of considering the variation of fluctuating flow needs to be developed. In this paper, a novel and simple model was developed that can predict the fluctuating ventilation rate due to the pulsating flow of single-sided, wind-driven natural ventilation in buildings. The model of the pulsating ventilation rate is derived based on the theory of wind engineering, the air compressibility, and inertia of air at the opening. The indoor and outdoor fluctuating wind pressure was constructed using a transfer function. It is found that there was an acceptable relative error of 13.9% compared with Haghighat’s model, which proved that the calculation method is reasonable. Finally, the model had also been used to analyze the effect of influencing parameters such as opening area, room volume, mean wind speed, turbulence intensity of the wind, and power spectrum density analysis on the pulsating ventilation rate.