Cross ventilation analyzed by recording pressure distribution on the floor of wind tunnel models

摘要

Cross-ventilation is difficult to predict and control because wind exhibits a large degree of variation in both speed and direction. Consequently, the design of a well functioning cross-ventilation system presently demands thorough and often expensive wind tunnel and CFD investigations. If one can lower the cost needed for these investigations much will be gained. This paper considers the possibility to classify types of flows based on straightforward static pressure measurements. The wind tunnel at the University of Gavle was provided with a pressure plate with 400 pressure taps organized in a square grid. Models of a house with two openings located opposite to each other were placed on the pressure plate and subjected to steady wind flow conditions. Three distinct types of flows were identified by systematically changing the opening size and recording the related static pressure distribution. The occurrence of the different regimes can be explained by jet flow theory. The most important parameter was the internal length of the house divided by a characteristic length of the opening which is the parameter associated with the development of jet flow.