A finite different method is developed to predict the side force on a high speedtrain in a cross-wind at low yaw anglee. The k-εturbulence model with wallfunctions is employed. the solution algorithm is based on curv...A finite different method is developed to predict the side force on a high speedtrain in a cross-wind at low yaw anglee. The k-εturbulence model with wallfunctions is employed. the solution algorithm is based on curvilinearnonorthogonal coordinates,covariant velocity components ,and staggered gridarrangement. The convective fluxes are described by the Power tow Scheme.A highly deformed grid generated with an elliptic grid generator is used aroundthe comero of the cross-section of the train. The results obtained comparepositively with wind tunnel experinients.展开更多
Ⅰ. INTRODUCTIONThe flow phenomena that exist in the advanced turbomachinery are extremely complex and propose a challenge to the engineers and scientists to improve the design procedure. The rapid progress of high sp...Ⅰ. INTRODUCTIONThe flow phenomena that exist in the advanced turbomachinery are extremely complex and propose a challenge to the engineers and scientists to improve the design procedure. The rapid progress of high speed and large capacity computers has encouraged the development of computational fluid dynamics that has had an increasingly important influence on turbomachinery blade design and analysis. Compared with the inviscid solver, the N.S.展开更多
Numerical modelling technique for ice flowing and melting field in coastal tidal currents for cooling water engineering design and research was presented based on k-Ε turbulence mathematical model and discretized mov...Numerical modelling technique for ice flowing and melting field in coastal tidal currents for cooling water engineering design and research was presented based on k-Ε turbulence mathematical model and discretized moving-boundary-fitting coordinate system. To treat the complicated geometric, topographic and hydraulic conditions in a natural estuarine water were given. Numerical results show that model is practical and efficient to cooling water engineering research. An engineering application has been conducted by using the prediction on ice reduction and melting process by heated water discharges.展开更多
为了分析近壁面处理方法对湍流数值计算的影响,应用几种不同的壁面处理方法,对长直圆管管内湍流进行了模拟计算,并将计算结果与试验数据进行对比。结果表明:壁面网格尺寸的选取对湍流计算结果具有较大的影响,且Viscous Grid Space Calcu...为了分析近壁面处理方法对湍流数值计算的影响,应用几种不同的壁面处理方法,对长直圆管管内湍流进行了模拟计算,并将计算结果与试验数据进行对比。结果表明:壁面网格尺寸的选取对湍流计算结果具有较大的影响,且Viscous Grid Space Calculator给出的壁面网格尺寸具有较好的应用性;壁面函数法在高雷诺数区域具有较高的计算精度,而低雷诺数湍流模型可较精确地模拟出近壁区的速度分布,其中Spalart-Allmaras湍流模型的计算结果与试验数据吻合得最好,该模型在湍流计算中具有较大的优势。展开更多
文摘A finite different method is developed to predict the side force on a high speedtrain in a cross-wind at low yaw anglee. The k-εturbulence model with wallfunctions is employed. the solution algorithm is based on curvilinearnonorthogonal coordinates,covariant velocity components ,and staggered gridarrangement. The convective fluxes are described by the Power tow Scheme.A highly deformed grid generated with an elliptic grid generator is used aroundthe comero of the cross-section of the train. The results obtained comparepositively with wind tunnel experinients.
基金Project supported by the National Natural Science Foundation of China
文摘Ⅰ. INTRODUCTIONThe flow phenomena that exist in the advanced turbomachinery are extremely complex and propose a challenge to the engineers and scientists to improve the design procedure. The rapid progress of high speed and large capacity computers has encouraged the development of computational fluid dynamics that has had an increasingly important influence on turbomachinery blade design and analysis. Compared with the inviscid solver, the N.S.
文摘Numerical modelling technique for ice flowing and melting field in coastal tidal currents for cooling water engineering design and research was presented based on k-Ε turbulence mathematical model and discretized moving-boundary-fitting coordinate system. To treat the complicated geometric, topographic and hydraulic conditions in a natural estuarine water were given. Numerical results show that model is practical and efficient to cooling water engineering research. An engineering application has been conducted by using the prediction on ice reduction and melting process by heated water discharges.
文摘为了分析近壁面处理方法对湍流数值计算的影响,应用几种不同的壁面处理方法,对长直圆管管内湍流进行了模拟计算,并将计算结果与试验数据进行对比。结果表明:壁面网格尺寸的选取对湍流计算结果具有较大的影响,且Viscous Grid Space Calculator给出的壁面网格尺寸具有较好的应用性;壁面函数法在高雷诺数区域具有较高的计算精度,而低雷诺数湍流模型可较精确地模拟出近壁区的速度分布,其中Spalart-Allmaras湍流模型的计算结果与试验数据吻合得最好,该模型在湍流计算中具有较大的优势。
