【摘要】 以180°圆形弯管为例,对弯管内流场的数值模拟方法进行了研究。分别采用k-ε模型,RNG k-ε模型和雷诺应力模型对弯管内流场进行计算,并将计算结果与试验测量结果进行了对比。结果表明:弯管内流体旋转产生的离心力导致了压力分布的变化,使得弯管内流体产生较强的涡流。在近内壁区中间位置,3种模型的计算结果与实验测量基本一致;在上半部分的1/2处,雷诺应力模型与标准k-ε模型的精度较高;在中心区,3种模型的计算结果与实验测量接近一致,但在弯管的进出口区域,雷诺应力模型的计算精度较高。近外壁区,3种模型的计算结果均反映了主流切向速度的变化趋势,但以雷诺应力模型计算精度最高。3种模型均反映了180°圆形弯管流场的主流切向速度的基本特征,但在一些速度变化较大,流场具有各向异性的局部区域,雷诺应力模型具有较高的预测精度,而标准k-ε模型与RNG k-ε模型存在着一定的局限性。更多还原

【Abstract】 The numerical simulation method for turbulent flow field in the curved duct is analyzed on the case of the 180° curved duct with circle cross-section. Three different turbulent models are considered during numerical calculation,including standard k-εmodel,RNG k-ε model and Reynolds stress model( RSM),and the flow predictions are compared against the experimental data. The results show that the pressure distribution is changed due to the centrifugal force generated by fluid rotating in the curved duct,which leads to strong vortex in the curved duct. At the interposition near inner wall,the calculation results of three models are in conformity with the experimental data,and the standard k-ε model and Reynolds stress model exerts higher accuracy at the 1 / 2 position of top half part. In the centre,the calculation results of three models are in conformity with the experimental data,but in the inlet and outlet of the curved duct,Reynolds stress model exerts higher accuracy. The calculation results of three models reflex the variation trend of fluid tangential velocity near outer wall,while Reynolds stress model has highest accuracy. The contrast indicates that three models have no great differences in the predictions of the various turbulence models,but the Reynolds stress model reveals more accurate for it considering the anisotropy.更多还原