NATURAL COORDINATES FOR ANALYSIS OF THE PRACTICAL STIRLING CYCLE

The appropriate choice of coordinate system so simplifies basic cycle analysis that computation of the ideal particle trajectory diagram reduces to a straightforward graphical process. Ideal pressure, Reynolds number N(re), friction factor C(f) and heat-transfer parameters N(st) and N(pr)2/3 follow in function of location and crank angle via a few steps on the hand calculator. A thermodynamic design parameter is identified which has essentially the same numerical value for such diverse Stirling engines as Philips' M P 1002CA, General Motors' GPU-3 and the turn-of-the-century Kyko hot-air engine.