West number
Description
The West number is an empirical parameter used to characterize the performance of Stirling engines and other Stirling systems. A Stirling engine is a heat engine that operates by cyclic compression and expansion of air or other gas (the working fluid) at different temperatures, such that there is a net conversion of heat energy to mechanical work. The West number is often used to approximate of the power output of a Stirling engine. The average value is (0.25) for a wide variety of engines, although it may range up to (0.35), particularly for engines operating with a high temperature differential.
Related formulasVariables
| Wn | The West number (dimensionless) |
| W0 | The power output of the engine (watt) |
| TH | The absolute temperature of the expansion space or heater (K) |
| TK | The absolute temperature of the compression space or cooler (K) |
| P | The mean average gas pressure (Pa) |
| V | Swept volume of the expansion space (m3) |
| f | The engine cycle frequency (Hz) |