Evaluation of Wind Pressure Distribution for Large-Span Warpage Roof via Wind Tunnel Testing and Numerical Simulation

In order to determine the wind pressure distribution characteristics of a large-span warpage roof structure, a wind tunnel test and numerical simulation were carried out for a large-span warpage roof. First, the distribution of roof pressure and influence of open doors and windows on the wind pressure distribution were analysed according to the wind tunnel test results. Then, the mean wind pressure distribution for the roof structure was simulated on a CFX software platform by using an RNG k-ε turbulence model, and the simulation results were compared to the wind tunnel test data. The results showed that the open doors and windows yielded little influence on the external wind pressure, and non-negligible influence on the internal pressure. Specifically, when the doors and windows of one side were opened, the roof was subjected to an upward lifting force. Alternatively, when both sides were opened at the same time, the internal pressure resulted in a downward suction on the roof. The RNG k-ε turbulence model was used to simulate the average wind pressure distribution of a large-span warpage roof structure, and was found to accurately reflect the actual wind pressure. The primary effect of wind pressure on the roof was suction, and the most unfavourable position of wind load occurred at the warping edge and in the rooftop area. When the flow direction occurred parallel to the warp direction, the wind flow yielded increased separation on the warp edge and a stronger vortex on the warp surface. Wind flowing around the building resulted in the separation and vortex occurring along both sides in the flow direction; additionally, two large symmetric trailing vortexes were formed on the leeward sides. However, there was no significant evidence of separation and vortex occurring on both sides when the wind flow was directed against warpage.