基于低矮建筑物实测数据的改进湍流物理模型

要准确模拟低矮建筑物壁面上分离涡位置的平均风压比较困难,这些区域在绕钝体流动中也是很关键的部位.本文在Spalart-Allamaras湍流物理模型的基础上,根据钝体绕流流场特性,结合低矮建筑物上的实测数据,调试并选取合适的参数,提高涡粘预测的准确性,提出了改进的S-A湍流物理模型.通过对6m立方体和Silsoe低矮建筑模型进行稳态数值模拟,由改进S-A湍流模型得到的屋面、背风和侧风面上平均风压结果,比目前公认的模拟钝体绕流效果较好的SST湍流模型有较大改善,比风洞实验更接近实测结果.由此可以看出,本文改进湍流模型的方法,将是一条提高预测建筑物表面平均风压精度很有效的途径.

Improved turbulence models for calculation of wind loading based on full-scale data on low-rise buildings

It is difficult to predict mean wind loads accurately in the separated flow region on the low-rise buildings by CFD,especially in the roof and rear of the buildings.This paper presents an improved turbulence model based on Spalart-Allamaras model.According to wind flow characteristic and full-scale pressure data on low-rise buildings some variables are adopted to improve the accuracy of turbulence model for calculation of wind pressures.The eddy viscosity could be predicted accurately with some appropriate parameters in the improved turbulence model.The improved Spalart-Allamaras model is applied to two fullscale models,6m cube and Silsoe Structure Building.The mean pressures on the roof and rear of the buildings are compared with field-measurement data,wind-tunnel data and numerical results using some other turbulences models.The improved Spalart-Allamaras model can get the best results compared to full-scale data.So improving the turbulence model based on full-scale data could be an efficient way to predict mean wind loads accurately.