机械

流体流通截面面积缩小是引起局部阻力的一种常见形式,常用渐变管来减小其阻力。针对一种小型热解处理设备,在流道截面缩小比例较大和轴向距离受限的情况下,建立三维数值计算模型,分析了不同结构参数对于局部阻力的具体影响。运用流体仿真软件,选用标准k-ε湍流模型,求解器采用高阶求解模式。计算得出内部流场的速度分布情况和局部全压降,对比分析出口圆角半径和直线渐缩管轴向距离对局部阻力系数的影响,为工程设计提供有益参考。

Sudden reduction of the circulation area is a common form cause the local resistance. Usually use gradient tube to decrease the resistance. In this paper, a three-dimensional numerical model is established for the case of a small scale pyrolysis equipment, in which there is a large ratio of the flow section shrink and the axial distance is limited. The specific effect on the local resistance is analyzed in this paper. The velocity distribution of the internal flow field and the local total pressure drop are obtained by calculate based on fluid simulation software. The turbulence model is standard k-ε model. The solver use high resolution pattern. The influence of the axial distance on the local resistance coefficient is compared with the radius of the outlet which provided useful reference to the engineering design.