Response surface method approach for analysing flow characteristics in an expanding channel

Abstract

Analysis of flow in an abruptly expanding channel for five characteristics namely sequent depth ratio Y2/Y1, efficiency E2/E1, relative height of jump hj/E1, relative length of jump Lj/Y1 and relative length of roller Lr/Y1 were studied experimentally and using response surface method (RSM) technique. Physical explanations of these characteristics against Froude number were also discussed based on experiments. Dimensional analysis has also been followed for different fluid properties and geometric dimensions of the set up for reducing number of complexity involved in hydraulic jump phenomenon. Obtained results are well presented as regression models for all flow characteristics. Furthermore, RSM is applied to determine most significant parameter influencing jump characteristics and to identify any unusual behaviour of flow parameters. The central composite rotatable design was employed to generate the experimental runs using Minitab software version 21. These developed models are characterised as highly accurate as prediction efficiency of RSM model is deemed highly effective for sequent depth, relative height, efficiency, relative length of roller and relative length of jump as reflected in the Nash–Sutcliffe efficiency values within the 0.9 NSE range.