火灾条件下气承式膜结构内压FDS模拟

以气承式膜结构为研究对象，利用火灾模拟软件FDS，在考虑亚格子网格中的气体渗漏的条件下，对气承式膜结构无火情况下内压的影响因素以及有火情况下内压的模拟方法开展了研究.结果表明，气承式膜结构的内压模拟应考虑进风量和渗漏面积影响，且进风量越大，渗漏面积越小，对应的内压稳定值越大.基于理论推导和数值模拟结果，得到了考虑进风量和渗漏面积影响的气承式膜结构内压预测公式，且公式预测结果与模拟结果吻合较好.对气承式膜结构有火情况下内压的模拟研究发现，点火时的内压、火源的热释放速率仅影响内压的变化过程，对内压的稳定值没有影响.因此，在内压为0Pa时引燃火源，可以得到火灾内压的极大值，并节约模拟时长.

FDS Simulation of Internal Pressure of Air-Supported Membrane Structure Under Fire

Taking the air-supported membrane structure as the research object， using the fire dynamics simulator(FDS)， and considering the air leakage in the subgrid， the influencing factors of the internal pressure of the air-supported membrane structure without fire and the simulation method of the internal pressure under fire were studied. The results showed that the influence of air supply volume and leakage area should be considered in the internal pressure simulation of the air-supported membrane structure， and the larger the air supply volume， the smaller the leakage area， and the larger the corresponding stability value of the internal pressure. Based on the theoretical derivation and numerical simulation results， the internal pressure prediction formula of the air-supported membrane structure considering the influence of air supply volume and leakage area is obtained， and the prediction results of the formula are in good agreement with the simulation results. The simulation study on the internal pressure of the structure under fire finds that the internal pressure at ignition and the fire’s heat release rate only affect the change process of the internal pressure but has no effect on the stability value of the internal pressure. Therefore， the fire can be ignited when the internal pressure is 0Pa， so as to obtain the maximum value of the internal pressure of the fire and save the simulation time.