Beale Number formula


The Beale number can be defined in terms of a Stirling engine’s operating parameters:

  • Bn= W o P V F


  • 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)


Beale number is a parameter that characterizes the the performance of Stirling engines.It is often used  to estimate the power output of a  String Engine design.For engines operating with a high temperature differential,typical values for the beale number are in the range 0.11 to 0.15