Outline of this calculated method

Following non-dimentional numbers is used in this prediction method.
Non-dimentional engine speed, n*:
Non-dimentional work, WS*:
Non-dimentional output power, LS*:
Non-dimentional engine specification, S*:
Design pressure ratio, P*:
Non-dimentional temperature, T*:

Ws: Output work in one cycle (J)
Pm: Mean pressure (Pa)
Plim: Design pressure (Pa)
VSE: Swept volume of expansion space (m3)
R: Gas constant (J/kgK)
TE: Gas temperature of expansion space (K)
TC: Gas temperature of compression space (K)
Tlim: Maximum temperature in design process (K)
: Viscosity coefficient at temperature, TE and pressure, Pm (m2/s)
lim: Viscosity coefficient at temperature, Tlim and pressure, Plim (m2/s)
n: Engine speed (rps)

* When you check 'Use the design and permitted values', Plim=Pmand Tlim=TE.

I have reduced the experimental data of Ecoboy-SCM81 and other high performance and low temperature difference Stirling engines.
Following figures show the relation between the non-dimentional engine speed, nmax*, and the non-dimentional output power, LSmax*, and the relation between the non-dimentional engine specification, S*, and the non-dimentional engine speed, nmax*. Experimental equations which are shown in the figures are estimeating the characteristics of the engines well.

Non-dimentional output power, LSmax* as a function of non-dimentional engine speed, nmax*

Non-dimentional engine speed, nmax* as a function of non-dimentional non-dimentional engine specification, S*

This performance prediction method calculates under above experimental equations.

Return to Simple Performance Prediction Method for Stirling Engine

All Right Reserved, Copyright(C), 1997, Koichi Hirata

Koichi Hirata (khirata@gem.bekkoame.or.jp)