基于边界层理论的建筑结构风致内压理论研究

由于单一开洞建筑结构风致内压是由黏性有旋的湍流流体引起的,伯努利方程显然不能完全适用于此种情况,因此采用边界层微分方程并结合湍流的半经验理论——混合长度理论——重新推导了风致内压控制方程,定义了新的能量损失系数及其具体表达式.采用标准四阶四段龙格-库塔数值计算方法求解内压控制方程,分析了能量损失系数对新方程计算结果的影响,并与经验公式的计算结果进行对比.研究结果表明,内压的能量耗散是由湍流扩散项引起的,进一步明确了洞口能量耗散的物理意义.

Wind induced Internal Pressure in Buildings Based on Boundary Layer Theory

Since wind induced internal pressure of a building with a large opening is usually caused by rolling viscous turbulent fluid and Bernoulli equation cannot be applied to this situation completely,a new governing equation for wind induced internal pressure with a single opening was derived using the boundary layer theory and the mixing length theory. Using the standard four order Runge Kutta numerical method to solve internal pressure governing equation,the influence of the energy loss coefficient on the calculation results of the proposed equation was analyzed and the calculation results of the proposed equation was compared with those of empirical formula.The results show that the internal pressure of the energy dissipation is caused by the turbulent diffusion term. Moreover, the physical meaning of the energy dissipation of the opening is further clarified.