![]() ![]() The method of characteristics (MOC) for the analysis of unsteady flow in a HRP system can be seen in Najm et al. He reported that performance features of the head ratio and the flow rate ratio relate directly to cyclic frequency. The expected performance is presented in a generalized form of the head ratio or discharge head to drive head and the flow rate ratio or discharge flow rate to drive flow rate. Iversen carried out a comprehensive investigation to identify the features of the HRP the drive head and flow, the discharge head and flow, the cycle frequency of the HRP, and the system efficiency. Details of the HRP working cycle are also described. They also reported that the maximum efficiency varied little with various adjustments of the waste valve, except perhaps for extremely high values of velocity in the drive pipe, at which the efficiency was somewhat lower. ![]() The dominant factor controlling the functioning of the HRP is the velocity in the drive pipe necessary to cause the waste valve to start closing, and its value is fixed by the waste valve setting. Experimental and theoretical investigations on HRPs were done by Lansford and Dugan to determine the rate of pumping and wasting for any conditions of operation. A short description of the function and history of HRPs can be found in Basfeld and Miiller. There are a number of studies which have been done to improve the design of HRPs by experimental, theoretical, and numerical approaches. Schematic diagram of the HRP test facility. Details of these are given by Watt, Schiller, Browne, and Inthachot et al. There are a lot of people in a lot of countries that build and use this kind of pump. HRP is one of the simplest and the most environmentally friendly devices for domestic or agricultural use. The only moving parts of the system are the waste valve and the discharge valve which operate from the fluid dynamic actions of the pumping cycle. The system consists of a drive pipe, waste valve, discharge valve, air (pressure) chamber, and delivery pipe (Figure 1). Water is pumped from a particular head at a high flow rate and comes out with a higher head but at a lesser flow rate because of the water hammer effect. In a HRP, no external powers are required to drive water. The concept of hydraulic ram pump (HRP) was developed 200 years ago. The experimental data reveal that the HRP characteristics are functions of the waste valve beats per minute and the supply head. But it tends to increase the head ratio, the flow-rate ratio, and the overall efficiency of the pump. An increase in waste valve beats per minute tends to decrease the supply flow rate, delivery flow rate, and delivery head. However, there was no significant difference on the HRP performance over a wide range of flow conditions when air chamber pressure was varied. An increase in air chamber pressure tends to decrease the overall efficiency of the pump. An increase in the supply head tends to increase the supply flow rate, delivery flow rate, delivery head, and the overall efficiency of the pump. The experiments on HRPs were conducted by which each of the following factors could be varied independently: (a) supply head, (b) air chamber pressure, and (c) waste valve beats per minute. The performance is presented in dimensionless terms as the head ratio or discharge head to drive head and flow-rate ratio or discharge flow rate to drive flow rate. To achieve this improvement, it is also necessary to understand the parameters that marked out the design of conventional HRPs. To make such a system economically competitive, it is necessary to improve the performance of HRPs. The possibility of using a hydraulic ram pump (HRP) as a means of utilizing its energy to produce high head for pump has been investigated. ![]()
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