A multi-grid finite-volume method for free-surface flows (original) (raw)
Abstract—A depth-averaged subcritical and/or supercritical, steady, free-surface flow numerical model is developed to calculate physical hydraulic flow parameters in open channels. The vertically averaged free-surface flow equations are numerically solved using an explicit finite-volume numerical scheme in integral form. The grid used may be irregular and conforms to the physical boundaries of any problem. A multi-grid algorithm has been developed and has subsequently been applied to accelerate the convergence solution. A grid clustering technique is also applied. The numerical approach is straight forward and the flow boundary conditions are easy enforced. The capabilities of the proposed method are demonstrated by analyzing subcritical flow in an abrupt converging-diverging open channel flume as well calculating supercritical flows in an expansion channel. The computed results are satisfactorily compared with available measurements as well as with other numerical technique results. Very coarse grid gives satisfactory comparison results. The explicit numerical code can be utilized, within the assumptions made about the nature of the flow, for various vertically averaged free-surface flow calculations. Scope is to simulate free-surface flows of practical interest in a straight forward way. It can be extended to channel designs.