圆管层流入口段数值模拟的差分格式与出口边界条件研究

AN INVESTIGATION ON DIFFERENCE SCHEME AND OUTLET BOUNDARY CONDITION FOR NUMERICAL SIMULATION OF LAMINAR DEVELOPING FLOW IN A CIRCULAR TUBE

通过数值模拟,分析了Re≥1000时,圆管层流入口段流场计算中采用一阶差分与QUICK格式的差别,研究了出口界面位置及两种不同的出口边界条件的影响。结果表明,对管内层流入口段流场计算,采用QUICK格式较一阶差分格式能更细致地反映流动过程。Re≥1000时,出口界面位置对采用一阶差分格式的计算结果影响不明显;对采用QUICK格式的计算,两种出口边界条件的差别与出口界面位置有关。

For the numerical simulation of laminar developing flow in a circular tube, when Re ≥ 1000, the first-order difference scheme and the QUICK scheme are compared, and the effects of outlet boundary position and two kinds of boundary conditions are investigated. The results show that, for the calculation of a laminar developing tube flow, more particular information of the flow can be given by the QUICK scheme than by the first-order difference scheme. For the case of Re ≥ 1000, the influence of the outlet boundary position on the calculated results is not obvious when the first-order difference scheme is adopted. When the QUICK scheme is applied, however, the difference between the results under the two kinds of outlet boundary conditions depends on the outlet boundary position.