Numerical Investigation of Wind Pressure Coefficients for Photovoltaic Arrays Mounted on Building Roofs: Fid-Bau Portal

Numerical Investigation of Wind Pressure Coefficients for Photovoltaic Arrays Mounted on Building Roofs

Li, Jiayang / Tong, Lewei / Wu, Jianming / Pan, Yeming

Abstract The wind pressure distribution on the photovoltaic (PV) array is of great importance to the wind resistance design. The flow field related to the pressure can be influenced significantly by the turbulence induced by the building roof edge (Kopp et al., 2012) and it is essential to consider the building effect during the investigation. However, most CFD (computational fluid dynamics) investigations of wind pressure distribution on the PV array are limited to ground mounted PV array without the building. There is a necessity to extend the application of CFD method to flows around roof-mounted PV array. This study investigated the wind pressure distributions on PV arrays mounted on building roofs by means of Reynolds-averaged Navier-Stokes (RANS) approach using the FLUENT software. Since RANS models are sensitive to the fiow condition, several RANS models are adopted and the most accurate RANS model for predicting this type of flow is identified based on a comparison with the wind tunnel experimental results. The SST Κ-ω model can predict the highest net mean wind uplift located at panels upstream accurately and is further applied for the parameter analysis to facilitate the installation of roof-mounted PV array. Numerical simulations of the wind flow field for wind angles between 0° to 180° were carried out at intervals of 20°, and the resulted net pressure distributions were presented. The influences of tilt angles of the PV array were investigated and the pressure distributions of PV panels were related to the flow field. Moreover, the effects of clearance between the PV array and building roof on the flow fields and pressure distributions of the PV array related to PV array tilt angle are studied.