管道内置等效阻力块对不可压缩流动流量的影响

The Influence of Equivalent Resistance Block Built in Pipeline on Incompressible Flow Rate

研究了管道内置等效阻力块的直径变化对管道不可压缩流动质量流量的影响。从流体力学连续性方程、动量方程和能量方程出发,推导了进出口截面动量修正后管道流动内置等效阻力块带来的质量流量变化计算公式。研究结果表明,流动损失主要由局部损失构成,当等效阻力块的直径较小时,流动损失主要为迎流断面局部损失;随着阻力块直径的增大,背流断面局部损失也增大,甚至超越迎流断面局部损失。在该研究的流动工况条件下,得到的计算公式的精度能满足工程应用要求。

The influence of the built-in r esistance block diameter of the pipeline on the mass flow rate of the incompressible flow is studied.Based on the fluid mechanics continuity equation,momentum equation and energy equation,the formula for the change of mass flow caused by the built-in equivalent resistance block of the pipeline flow after the momentum correction of the inlet and outlet section is derived.The research results show that:the flow loss is mainly composed by the partial loss of the upstream section and the back section,when the equivalent resistance block diameter is small,the flow loss is dominated by the upstream section partial loss;as the diameter of the resistance block increases,the partial loss at the back flow section increases,even exceeding the partial loss at the front flow section.The precision of the deduced calculation formula can meet the requirements of engineering application under the flow conditions of this study.