4 Impulse momentum equation Resultant force acting on the fluid is made up of three components:F1 = FR: by any solid body touching the control volumeF2 = FB: body force such as gravityF3 = FP: fluid PressureThe Force exerted by the fluid on the solid body is opposite to FRThe reaction force R is given by:R = - FR
5 Application of the momentum equation Impact of a jet on a plane surfaceForce due to flow round a curved vaneForce due to the flow of fluid round a pipe bendReaction of a jet
7 PurposeTo investigate the reaction force produced by the impact of a jet of water on various target vanes.Impact Jet Apparatus
8 Procedure:Position the weight carrier on the weight platform and add weights until the top of the target is clear of the stop and the weight platform is floating in mid position.Start the pump and establish the water flow by steadily opening the bench regulating valve until it is fully open.The vane will now be deflected by the impact of the jet.Place additional weights onto the weight carrier until the weight platform is again floating in mid position.Measure the flow rate (volume collected in certain time) and record the result on the test sheet, together with the corresponding value of additional weight on the tray.Observe the form of the deflected jet and note its shape.
9 Procedure:Reduce the weight on the weight carrier in steps and maintain balance of the weight platform by regulating the flow rate in about eight or ten even steps.Close the control valve and switch off the pump. Allow the apparatus to drain.Replace the 5mm nozzle with the 8mm diameter nozzle and repeat the tests.Replace the normal vane with the conical vane and repeat the test with both the 5mm and 8mm nozzles.Replace the conical vane with the hemispherical vane and repeat the test with both the 5mm and 8mm nozzles.
10 Data & Results: Target Vanes (degrees) Nozzle Dia -- d -- (mm) Additional Weights-- m -- (gm)Volume of Collected water - V - (Liter)Time to collect -- t -- (sec)590θ=Flat845Conical135Semi-spherical