Impacts of wind on solar chimney performance in a building

The interaction between solar chimney and wind were investigated numerically and theoretically. A higher wind velocity does not represent a better performance, which depends on wind angle (alpha), which is the angle between wind direction and outward normal of the wall with the window. A windward situation (0 degrees <= alpha < 90 degrees) is suggested, where the scenario with alpha= 0 shows the best performance. It is surprising that the leeward scenario with alpha = 180 degrees presents a slightly positive effect, but scenarios with 90 degrees <= alpha < 180 degrees show negative effects. Window area (A(w)) presents a positive effect on the airflow rate, which shows a linear relationship with A(w)(0.34) and A(w)(0.46) when the alpha is 0 degrees and 45 degrees, respectively. A theoretical model was developed to predict the airflow rate under alpha < 90 degrees, where for 90 degrees <= alpha < 180 degrees the related predictions can be based on the scenario without wind. The predictions are fitting quite well with numerical results. Critical wind velocity was also proposed to represent the wind velocity which overrules the performance that solar chimney is no longer dependent on solar radiation but wind. The critical wind velocity keeps increasing under higher solar radiation, where for the analysed model it increases from 0.65 to 1.55 m/s when solar radiation rises from 100 to 1300 W/m(2). (C) 2019 Elsevier Ltd. All rights reserved.