A pump supplies mechanical energy to a fluid so that it can flow against resistance or gain elevation. For a steady incompressible stream, a rise in pressure at similar inlet and outlet heights and speeds represents useful fluid power , where is the volumetric flow rate. Differences in kinetic energy and gravitational potential energy must be included when those conditions do not hold.
A real installation chooses its flow through the interaction between the pump's pressure-flow response and the connected passages. More resistance generally shifts the pump operating point, so the nameplate or rotational speed alone does not determine mass flow rate. Measuring inlet/outlet pressures, flow and supplied mechanical power separates useful fluid output from dissipative losses. A centrifugal pump uses a rotating impeller; a displacement device instead moves a defined volume during a cycle, with leakage and compressibility affecting the actual delivery.
A rotating-impeller pump that transfers mechanical energy to a fluid. At a fixed speed its head varies with flow; its characteristic curve and the connected system determine the pump operating point.
The flow and head at which a pump's characteristic curve intersects the hydraulic system's required-head curve. Increasing system resistance at unchanged speed normally reduces flow on a conventional falling pump curve.[ref]
Thermodynamics, Heat Transfer, and Fluid Flow, Volume 3 by the United States Department of Energy. Module HT-03, pp.51–53, System Operating Point
Articles by others on the same topic
"Pump" can refer to different things depending on the context. Here are a few common interpretations: 1. **Mechanical Device**: A pump is a mechanical device that moves fluids (liquids or gases) by mechanical action, often converted from electrical energy or another form of energy. Pumps are used in various applications, including water supply, heating and cooling systems, industrial processes, and more.