SUPERCRITICAL-FLOW NEAR AN ABRUPT WALL DEFLECTION

The supercritical flow near an abrupt wall deflection is investigated experimentally and by computer simulations. An extensive series of tes ts were conducted on a 500 mm wide flume with Froude number up to 8 an d wall deflection angle up to 11.3-degrees. A special inlet box was in stalled to provide smooth flow conditions at the flume entrance. By an alyzing the experimental data, explicit expressions are derived for th e height of the shock and the velocity ratio. Experimental results are presented in the form of universal plots of the shock surface and the two-dimensional velocity field. These may be utilized for engineering applications or for the verification of mathematical models. The flow field near a wall deflection was computed by using a two-dimensional flow model based on the numerical solution of steady, shallow-water eq uations by the MacCormack explicit finite-difference scheme. The compu ted and measured flow depths and flow velocities are compared and are found to be in satisfactory agreement where the assumption of hydrosta tic pressure distribution is valid. Although the computer simulation c an predict the location of the jump as well as its equilibrium depth, several features of the flow resulting from non-hydrostatic pressure d istribution are not resolved properly.