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2个U型组合的90°4片弯管流场非常复杂,确定其水头损失和相互影响系数不容易,一般水力计算手册中对此也尚乏介绍.采用计算流体动力学理论和计算方法,在验证了数学模型和网格划分方法可行性和准确性的前提下,模拟了2个U型组合的90°4片弯管流场并计算了该管段的局部水头损失,分析了相互影响系数随Ls/D的变化规律.研究表明:增大转弯半径可以减小局部水头损失;减小2个90°4片弯管间的直管长度可以减小局部水头损失;相互影响系数随Ls/D增大而不断趋近1.0;若R/D≥1,则当Ls/D等于0时,该值取得最小,局部水头损失也最小.
The flow field of 90 ° 4-bend pipe with two U-shaped combinations is very complicated, so it is not easy to determine the head loss and mutual influence coefficient, which is still not available in the manual of hydraulic calculation.Using computational fluid dynamics theory and calculation method, After verifying the feasibility and accuracy of the mathematic model and the meshing method, the flow field of 90 ° 4-bend pipelines with two U-shaped combinations was simulated and the local head loss of the pipe section was calculated. The interaction coefficient With the variation of Ls / D.The results show that increasing the turning radius can reduce the local head loss, reducing the length of straight pipe between two 90 ° four-bend pipe can reduce the local head loss.The mutual influence coefficient increases with Ls / D increases and continues to approach 1.0; if R / D ≥ 1, then when Ls / D is equal to 0, the value is minimized and the local head loss is also minimal.