摘要
通过实验与数值模拟对比验证了k-ε湍流模型用于模拟圆管突扩流场的可行性。对处于湍流水力光滑区(4000<Re<105)的8组Re流态下,突扩比为2.0、2.5、3.0、3.5、4.0、5.0的工况分别进行数值模拟。研究结果表明数值模拟计算得到的局部阻力系数小于传统理论公式局部阻力系数,两者差距随Re的增大而减小。分析得知该结果是由于局部阻力系数传统计算公式未考虑沿程水力损失所造成,沿程水力损失随Re的增加而降低,因此数值实验结果与理论公式计算结果会随Re的增大而减小,传统计算公式在小Re的工况下误差高达14%。
By comparing the experimental and numerical simulation ,we verify that the k-εturbulence model can be used to simulate the flow field of sudden enlargement in circular pipes and extended working conditions .Numerical simulation experiments are con‐ducted in the turbulent smooth areas （4 000〈 Re〈105） of 8 groups of Reynolds number flow state ,with the sudden expansion ratios 2 .0 ,2 .5 ,3 .0 ,3 .5 ,4 .0 ,5 .0 .The results show that the local loss coefficient value obtained experimentally is less than the calculated value through traditional theory .The gap between the two cases decreases with the increase in Reynolds number .An analysis shows that the results are due to the traditional formula of local loss coefficient ignored hydraulic losses along the tube .Frictional head loss decreases with the increase in Reynolds number .So the gap between the numerical results and calculated values decreases with the increase in Reynolds number .The deviation of traditional calculation causes conditions of low Reynolds number to reach 14% .
出处
《中国农村水利水电》
北大核心
2015年第9期144-146,149,共4页
China Rural Water and Hydropower
基金
国家自然科学基金(51279172)
西华大学研究生创新基金(YCJJ2014065)
关键词
圆管突扩
局部阻力
数值模拟
CFD
circular pipe sudden enlargement
local resistance
numerical simulation
CFD
作者简介
黄长久（1991-），男，硕士研究生，研究方向为流体机械流动理论、数值及实验研究（多相流）。E—mail：huangcjcm—ht@sina．com。
