基于Smagorinsky和Vreman模型的竖通道内旋转热流场大涡模拟

Large eddy simulation of fire whirls in a vertical shaft based on Smagorinsky and Vreman subgrid-scale models

为了确定Vreman亚格子模型对于有侧开缝的竖通道内旋转火焰热流场模拟的适用性,基于一竖通道内旋转火焰实验场景,分别使用基于Smagorinsky和Vreman亚格子模型的大涡模拟技术进行了模拟。通过对所得结果比较确定基于Smagorinsky亚格子模型的大涡模拟技术可以得到与实验吻合的火焰状态,而使用Vreman亚格子模型会在一定程度上低估旋转火焰周围的粘性耗散,从而过高地估计旋转火焰周围的切向速度,使火焰不能保持相对稳定的旋转状态。

In order to determine the suitability of the Vreman subgrid-scale model for the fire whirls flow field in a vertical shaft with a side slit,numerical simulations by Large Eddy Simulation（ LES） were conducted according to use cases based on the Smagorinsky and Vreman subgrid-scale models. The comparison results illustrated that the flame state obtained by using the LES technology based on the Smagorinsky subgrid-scale model was in alignment with the experiment. However,numerical simulation results based on the Vreman subgrid-scale model underestimated viscous dissipation near the flame to some extent. Consequently,overestimating the tangential velocity near the fire whirls prevents fire whirls from remaining in a stable state.