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In [[mechanical engineering]], the '''Beale number''' is a parameter that characterizes the performance of '''[[Stirling engine]]s'''. It is often used to estimate the power output of a Stirling engine design. For engines operating with a high temperature differential, typical values for the Beale number range from ( 0.11 ) to ( 0.15 ); where a larger number indicates higher performance. | |||
==Definition== | |||
The Beale number can be defined in terms of a Stirling engine's operating parameters: | |||
:<math>B_n = \frac{Wo}{P V F} </math> | |||
where: | |||
*'''B<sub>n</sub>''' is the Beale number | |||
*'''Wo''' is the power output of the engine ([[watt]]s) | |||
*'''P''' is the [[Arithmetic mean|mean average]] gas [[pressure]] ([[Pascal (unit)|Pa]]) or ([[MPa]], if volume is in [[centimeters|cm<sup>3</sup>]]) | |||
*'''V''' is swept [[volume]] of the power piston([[meters|m<sup>3</sup>]]) or ([[centimeters|cm<sup>3</sup>]], if pressure is in [[MPa]]) | |||
*'''F''' is the engine cycle frequency ([[Hertz|Hz]]) | |||
==Estimating Stirling power== | |||
To estimate the power output of an engine, nominal values are assumed for the Beale number, pressure, swept volume and frequency, then the power is calculated as the product of these parameters, as follows: | |||
<!-- Power = (Beale number) x (mean pressure) x (Swept volume of power piston) x (Frequency) --> | |||
:<math>Wo = \frac{}{}B_n P V F </math> | |||
==See also== | |||
* [[West number]] | |||
==External links== | |||
* [http://www.bekkoame.ne.jp/~khirata/academic/simple/simplee.htm Stirling Engine Performance Calculator] | |||
{{heat engines}} | |||
[[Category:Dimensionless numbers]] | |||
[[Category:Piston engines]] | |||
[[Category:Mechanical engineering]] | |||
{{thermodynamics-stub}} | |||
{{mech-engineering-stub}} | |||
Revision as of 00:08, 1 October 2013
In mechanical engineering, the Beale number is a parameter that characterizes the performance of Stirling engines. It is often used to estimate the power output of a Stirling engine design. For engines operating with a high temperature differential, typical values for the Beale number range from ( 0.11 ) to ( 0.15 ); where a larger number indicates higher performance.
Definition
The Beale number can be defined in terms of a Stirling engine's operating parameters:
where:
- Bn is the Beale number
- Wo is the power output of the engine (watts)
- P is the mean average gas pressure (Pa) or (MPa, if volume is in cm3)
- V is swept volume of the power piston(m3) or (cm3, if pressure is in MPa)
- F is the engine cycle frequency (Hz)
Estimating Stirling power
To estimate the power output of an engine, nominal values are assumed for the Beale number, pressure, swept volume and frequency, then the power is calculated as the product of these parameters, as follows: