Application of variable-blockage method to steady flows over curved beds

The variable blockage method of simulating flow problems with a free-surface is described. The method is based upon the fact that the surface pressure of water flow in open air is uniform, and the idea that the space occupied by the atmosphere can be numerically made inaccessible to the water by the setting of relevant blockage factors. Advantages of the method are its ability to predict steady free-surface problems and its easy application to nonpotential flows, i.e., to those which are not free of viscous effects. The method was applied to the prediction of steady flows over curved beds. Experimental verification of numerical free-surface form and bed-pressure profile validate the physical realism of the method. Although the method is only evaluated against experimental observation under the shallow flow condition, application to deep flow predictions may be found without introduction of any extra difficulties. The method is very easy to use when the computer program is equipped with the ability to assign the blockage factors.