Power output of a stirling engine (Beale Number) :

where:

• B_n 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)