圆管变径局部水头损失的数值模拟

Numerical Simulation on Local Resistance of Reducing Pipe

管网布置及设计中,局部损失的计算非常重要,但由于其影响因素多,目前常采用经验值简化计算,误差较大.圆管变径是一种常见的管道连接方式,对其局部阻力影响因素进行研究有重要意义.通过采用数值模拟方法对供热管道设计中两次变径或跳径管段的局部水头损失进行数值模拟,绘制不同管径变化时跳径和两次变径的二维模型,分析研究了其阻力特性.模拟结果表明:相同管径和流量下,跳径的阻力损失总比两次变径的阻力损失大.

The calculation for partial loss is very important in the layout and design of a pipe system. However, because there are many factors which could affect the results, the empirical coefficient method is applied to the calculation which is inaccurate. Reducing Pipe is a common pipe connec- tion way,which is significant to analyze the factors influencing local resistance. Through the nu- merical simulation method, the numerical simulation of the local head loss of the two variable or jump pipe sections in the design of the heating pipe is carried out,the two-dimensional model of jump diameter and two variable diameters under different diameters is drawn,and the resistance characteristic is analyzed. The simulation results show that the resistance loss of the jump diame- ter is larger than that of the two diameters.