Performed by: Lee C. GroenewegProfessor: Dr. FleischmannOutlineI. PurposeEgr 365 Lab 4bConservation of Momentum – Impact of a JetPerformed by: Lee C. GroenewegPerformed on: June 22nd, 1999Professor: Dr. FleischmannOutlineI. PurposeII. BackgroundIII. Process OverviewIV. ProcedureV. Results VI. ConclusionsVII. Design QuestionsPurpose:To experimentally determine the impact force of a jet deflected through a known angle and to compare the experimental results to predictions from a control volume analysis of an inviscid fluid.Background:Force can be determined as the rate at which momentum changes in a system, F=d(mv)/dt. When a fluid is deflected by a solid surface the fluid momentum changes because the direction changes and it therefore exerts a force on that surface. The impact force can be calculated using a control volume analysis. Good results are generally obtained by also assuming the fluid to inviscid (non-viscous). Although real fluids are viscous and viscous interaction is responsible for some of the force, most of the force exerted in these cases is due to changes in fluid momentum (specifically direction). Process Overview:In this lab the impact force of a jet was to be determined experimentally and compared to control volume predictions. Figure 1 shows the control volume used to base the results on.Figure 1. Control volume for jet In order to determine the impact force we needed to calibrate our apparatus so thatwe would be able to determine how much force corresponds to a measured displacement. After the calibration of the machine was completed, we began to measure the displacements for discrete mass flow rates. These measured displacements would then be compared to the calibrated values to determine the experimental values for the impact force. These force values were then compared to the results for the same inputs resulting from the control volume analysis. The control volume analysis and the derivations of the necessary equations are attached as Appendix A1 Procedure:In order to measure the impact force of the jet we had to calibrate the machine to determine what displacement resulted from a given force. The calibration was done by placing weights of known value into the opening where the fluid would enter. The deflection of the beam in the apparatus was measured by counting the number of ticks past zero on a circular disk. The value for the displacement was measured when anelectrical connection was made between the jet and the disk, as indicated by an LED. Once this data was taken it provided us a base to determine the force that would be created by the fluid flow. The calibration curve is attached as Appendix B1. Once the apparatus was calibrated, we then attached a 2.41mm diameter orifice tothe flow valve to create the jet. With the orifice in place we then let fluid flow through theapparatus at discrete mass flow rates. The mass flow rates were determined by reading the calibrated column attached to the side of the apparatus. For the given mass flowrate, we measured the displacement, which then was used to determine the impact force using the calibration curve. We took data for several mass flowrates to see if there was any trend to the data. Results:The graph attached as Appendix B2 shows the displacements as a function of the mass flow rates. The graph attached as Appendix B3 shows the impact forces as a function of the mass flowrates. The graph includes both the experimental values and the values that were obtained using the control volume approach. Conclusions:The purpose of this lab was to experimentally determine the impact force of a jet deflected through a known angle and to compare the experimental results to predictions from a control volume analysis of an inviscid fluid As shown in the graph of Appendix B3, the results for the experimental and control volume analysis diverge as the mass flowrate increases. It is worth noting that the control volume analysis was done without considering the effects of the fluid viscosity, and gravity. This would affect exiting flow speeds and the impact force, which may explain some of the variance in the results. If such factors as gravity and viscosity were considered in the control volume analysis, the results may be more agreeable. In spite of this, there appears to be a similar trend in both sets of data thus allowing the objective of this lab to be met.Design Questions:In addition to this lab some consideration was to be made concerning another typeof jet reaction situation. This situation is the same type of reaction, except that the fluid used is water. The volumetric flowrate was set at 5 gallons per minute, an approximate value for the flow from a faucet in a house. The faucet opening was measured to be 0.75 inches as the orifice diameter. The results for the force and flow speed (velocity) were calculated using the control volume approach. Therefore, the values reported in AppendixC1 are entirely theoretical. Since the mass flowrate was given to us, there is nothing to report on the selection of a flowrate measuring