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Paschen's law is an equation that gives the breakdown voltage, that is, the voltage necessary to start a discharge or electric arc, between two electrodes in a gas as a function of pressure and gap length. [2] [3] It is named after Friedrich Paschen who discovered it empirically in 1889. [4]
Discharge Head, is the net head obtained at the outlet of a pump. For a centrifugal pump, the discharge pressure depends on the suction or inlet pressure as well, along with the fluid’s density. Thus, for the same flow rate of the fluid, we may have different values of discharge pressure depending on the inlet pressure.
The affinity laws are useful as they allow the prediction of the head discharge characteristic of a pump or fan from a known characteristic measured at a different speed or impeller diameter. The only requirement is that the two pumps or fans are dynamically similar, that is, the ratios of the fluid forced are the same.
Specific Pump Power (SPP) is a metric in fluid dynamics that quantifies the energy-efficiency of pump systems. It is a measure of the electric power that is needed to operate a pump (or collection of pumps), relative to the volume flow rate. It is not constant for a given pump, but changes with both flow rate and pump pressure.
An axial-flow pump for industrial use. An axial-flow pump, or AFP, is a common type of pump that essentially consists of a propeller (an axial impeller) in a pipe.The propeller can be driven directly by a sealed motor in the pipe or by electric motor or petrol/diesel engines mounted to the pipe from the outside or by a right-angle drive shaft that pierces the pipe.
In fluid dynamics, total dynamic head (TDH) is the work to be done by a pump, per unit weight, per unit volume of fluid.TDH is the total amount of system pressure, measured in feet, where water can flow through a system before gravity takes over, and is essential for pump specification.
The static head of a pump is the maximum height (pressure) it can deliver. The capability of the pump at a certain RPM can be read from its Q-H curve (flow vs. height). Head is useful in specifying centrifugal pumps because their pumping characteristics tend to be independent of the fluid's density. There are generally four types of head:
A positive-displacement pump must not operate against a closed valve on the discharge side of the pump, because it has no shutoff head like centrifugal pumps. A positive-displacement pump operating against a closed discharge valve continues to produce flow and the pressure in the discharge line increases until the line bursts, the pump is ...