| 摘要 |
<p>Adiabatic Positive Displacement Machinery Adiabatic positive displacement gas cycle machinery is designed with explicit control of the heat flow between the gas and the walls. The control is achieved by maintaining near-laminar flow and a small wall area to volume ratio. The most stable nearlaminar flow in a cylinder is an axial vortex because of symmetry, and hence the induction port design should establish an axial vortex and a low velocity. Induction and exhaust port designs to achieve this flow are applied to a vane pump, an adiabatic air compressor, a diesel engine, and four stroke Otto cycle engines. The gain in thermal efficiency for these designs can be significant, up to a factor of 2, since the largest inefficiency in nearly all positive displacement machinery is imperfect control of heat flow.</p> |
