A Numerical Study on the Open Channel Flow with Plane Wall Jet Inlet Boundary Condition

평면벽면분류의 유입경계조건을 가지는 개수로 유동에 관한 수치적 연구

A numerical work was performed to study the flow behaviors of the open channel type flow with its geometric boundary conditions being similar to that of the Multi-Stage-Flash evaporator with and without a baffle. For the analysis, two-dimensional steady turbulent flow was assumed and the widely known k-.epsilon. turbulence model was usded. SIMPLE algorithm and the power difference scheme were used for the numerical approach. Numerical results generally agree with the previous experimental results though there are some uncertainties at far downstream and near the free surface due to the three dimensionality of the flow and surface waves. Without a baffle, the flow has basically the shape of the submerged plane wall jet with its upper boundary at downstream being sharply curved toward the free surface. For the flow with a baffle, recirculation flow patterns are observed at the upper inlet portion and at the backside of the baffle. For the case without a baffle, it was also confirmed that the ratio between the liquid level and the gate opening height is the most important parameter to determine the flow behavior.

본 수치적 해석에서는 H$_{w}$/H$_{g}$의 비가 5.0~16.7의 범위에서 수행된 실험결과를 바탕으로 기존의 ｋ-.epsilon. 난류모델을 사용하여, 고려하고자 하는 변수, 즉 유입유속, 입구 게이트의 높이, 수위, 배플의 유.무등에 따라서 액체의 유동형태가 어떻게 변하는가를 살펴 보고자 한다.다.