通道倾斜角度对开口中性面位置影响

Research on the impact of an inclined angle on the positions of neutral planes at two open ends of a channel

为了了解通道在倾斜状态下开口中性面随倾斜角度的变化,该研究采用实验和数值计算方法对倾斜角度为0°、10°、20°和30°的通道两端开口处的流场进行了测量和模拟.基于大涡模拟湍流模型求解浮力驱动N-S方程的数值模拟方法求得的模拟结果和实验值吻合较好,通过对通道两端开口处中性面位置比较发现,随着通道倾斜角度的增大,低端开口的中性面高度逐渐上升,高端开口的中性面高度逐渐下降;倾斜角度为0°时,通道两端开口流场呈对称分布,中性面下部流进通道气体流速较小;倾斜角度超过20°时,低端开口中性面已升到开口的最上端,高端开口处的气流以流出通道为主,中性面高度已降至开口下边缘.该研究为改进通道内排烟、通风效率和空气质量提供了参考和帮助.

In order to understand the characteristics of a neutral plane at an inclined channel under different angles,and then offer instructions to improve the smoke exhaust,ventilation efficiency,and air quality,this paper analyzed two open ends of a channel inclined with angles of 0°,10°,20°,and 30° by experiments and numerical simulations.The experimental data agreed well with the predicted results by using large eddy simulation（LES） to solve N-S equations driven by the buoyancy flow.By comparing the neutral plane heights of the two open ends,it was found that the height of the neutral plane increased at the low end,while it decreased at the high end with an inclined angle.Furthermore,when the angle was 0°,the flow fields of the two ends were symmetrical,and the air flowed in the channel with a low velocity under the neutral plane.When the angle was 20°,the height of the neutral plane at the low end rose to the top of the open end,and the height of the neutral plane at the high end fell to the lower part of the open end with the air mainly flowing out of the channel.