Numerical Modeling Investigation of Secondary Current Cells in Trapezoidal Channels and their Effect on Hydraulic Jump’s Properties

A hydraulic jump occurs when a supercritical flow has to change into subcritical flow, there is a sudden rise in the water surface and considerable loss of energy in a hydraulic jump. In this paper analyzed the trapezoidal channels properties in 3 different lateral angles , 45°,60° and 75°,  by numerical modeling and computational fluid dynamic methods by flow 3D software, and has been investigated the effect of secondary currents flow cells on hydraulic jump, The results shows that hydraulic jump energy loss reduced by 45  to the other sections, and also shows the opposite relation between the secondary currents  flow velocity in the horizontal direction (Vx) and the vertical direction (Vz) .and at last air entrainment volume in 45  section at the begging of jump was more than the 75  section, so that it was ranged 0.155 m3 in 75  to 0.17 m3 in 45  .The ratio of the increase in the x direction of velocity of the secondary currents in the 45 ° was 76% to the 75°.