关键词: 大涡模拟, 风速合成, 风载, 相控阵天线

Abstract: Wind load is a main load on phased array antenna in atmospheric boundary layer. In view of the limitation that Gaussian stationary random process theory is unable to compute the transverse fluctuating wind load, and the unreasonableness that the fluctuating velocity is generated by spectral method in computational fluid dynamics (CFD), a method to compute the wind load on antenna in atmospheric boundary layer is presented by combining CFD and simulation technique of turbulent wind field. Based on the power spectral density function proposed by Kaimal, the longitudinal and transverse fluctuating wind velocity at some points are simulated by using the weighted amplitude wave superposition method, and added to the boundary conditions of computational model. Adopting dynamic Smagorinsky subgrid scale stress model in large eddy simulation, the time histories of wind pressure and wind load on a phased array antenna are computed, and compared with the data of a standard model with the same shape as the antenna which are obtained by numerical simulation and wind tunnel test. The results suggest that the computed results that the places of simulated points are reasonably arranged are in good agreement with the data from wind tunnel test in different directions. The method can be applied to the computation of time-history of wind pressure and wind load on structures in atmospheric boundary layer, thus having a widespread universality and important engineering application value.

Key words: Large eddy simulation, Phased array antennas, Synthesized wind velocity, Wind load