【摘要】 采用二维轴对称不可压缩N-S方程,利用有限体积方法和SIMPLE算法,对不同母线型式的扩缩管对流换热特性进行了数值模拟。在给定入口速度、温度型线的条件下,分别研究了层流和湍流状态下均匀、线性、抛物线等三种典型入口型线对对流换热性能的影响。探索了不同母线型式对传热强化的影响,得到了对流换热随母线形状的变化规律。在给定的状态中得到了一个比较适当的母线外形,使得扩缩管的传热性能有所优化。更多还原

【Abstract】 Using the two-dimensional symmetric incompressible laminar N-S equation,a numerical study of heat transfer characteristics of diverging-converging tubes with different generatrices is carried out with the finite volume method and SIMPLE algorithm.Three typical velocity and temperature profiles are specified at the inlet,i.e.uniform,linear and parabolic distributions.Effects of different inlet profiles and generatrices of diverging-converging tubes on heat transfer enhancement characteristics are studied.Variations of laminar and turbulent convective heat transfer characteristics in these tubes with different generatrices are obtained.Under the given conditions,a more appropriate generatrix is obtained through optimizing the heat transfer performance of the diverging-converging tube.更多还原