Power density is the amount of
power (time rate of
energy transfer) per unit
volume
Volume is a measure of occupied three-dimensional space. It is often quantified numerically using SI derived units (such as the cubic metre and litre) or by various imperial or US customary units (such as the gallon, quart, cubic inch). Th ...
.
In
energy transformers including
batteries
Battery most often refers to:
* Electric battery, a device that provides electrical power
* Battery (crime), a crime involving unlawful physical contact
Battery may also refer to:
Energy source
*Automotive battery, a device to provide power t ...
,
fuel cell
A fuel cell is an electrochemical cell that converts the chemical energy of a fuel (often hydrogen fuel, hydrogen) and an oxidizing agent (often oxygen) into electricity through a pair of redox reactions. Fuel cells are different from most bat ...
s, motors,
power supply
A power supply is an electrical device that supplies electric power to an electrical load. The main purpose of a power supply is to convert electric current from a source to the correct voltage, current, and frequency to power the load. As a ...
units etc., power density refers to a volume, where it is often called volume power density, expressed as W/m
3.
In
reciprocating internal combustion engine
An internal combustion engine (ICE or IC engine) is a heat engine in which the combustion of a fuel occurs with an oxidizer (usually air) in a combustion chamber that is an integral part of the working fluid flow circuit. In an internal co ...
s, power density (power per
swept volume or
brake horsepower per cubic centimeter) is an important metric, based on the ''internal'' capacity of the engine, not its external size.
Examples
See also
*
Surface power density, energy per unit of area
*
Energy density, energy per unit volume
*
Specific energy, energy per unit mass
*
Power-to-weight ratio
Power-to-weight ratio (PWR, also called specific power, or power-to-mass ratio) is a calculation commonly applied to engines and mobile power sources to enable the comparison of one unit or design to another. Power-to-weight ratio is a measuremen ...
/specific power, power per unit mass
**
Specific absorption rate (SAR)
References
Power (physics)
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