Experimental study of the effect of the trashrack on the vortex at the intake of the hydroelectric power plants in various flow rates and submergence depths

One of the main problems commonly encountered by the intakes of the power plants is the formation of vortex and turbulent flow at the intake of the reservoirs.Using the image processing method by using the PTV technique in a survey flow hydraulic of a horizontal intake with a trashrack by certain opening,under the submergence depths and different flow rates and comparing it with intakes without trashrack is the subject This paper addresses this issue.The used Trashrack has an opening percentage of about 64%, and these experiments were carried out on 6 Froude Number of 0.6,0.8, 1,1.2,1.4 and 1/6 and 5 ratios of the depth of submergence to intake diameter 1,1.5, 2,2.5 and 3.It should be noted that the diameter of the intake is 16 cm in the form of bell-shaped lips up to 21 centimeters.According to the results the best trashrack performance has been achieved in reducing the vortex strength in the 1 Froude number.On this Froude number,on average,about 56% of the vortex power reduction has been achieved by installing the trashrack.In general,it can be said that the greatest effect of the trashrack on the relative depths submergence is 2 and 1.5 and the Froude numbers are 1 and 1.4.