Dwell Mechanism for Increasing Free-Piston Stirling Engine Specific Power and Efficiency

Proposed is a displacement dwell mechanism for increasing Stirling engine power output and efficiency. The dwell mechanism allows for deviations from a sinusoidal displacement profile found in crank-driven Stirling engines. Longer dwell allows slightly more time for heat transfer to occur in both the hot- and cold-side heat exchangers. Preliminary simulations using freely available Stirling engine simulation code by Israel Urieli indicates that even a modest increase in dwell time increases power output and efficiency. Increasing the power output and efficiency of a Stirling engine by way of a simple mechanical device represents the ?low hanging fruit? compared to complex and expensive regenerator/heat exchanger optimization and development.