The Stirling engine is an external combustion engine that uses heat exchangers to enhance 7 the addition and removal of energy. This makes the engine power dense but expensive, less efficient 8 and complicated. In this contribution, the Stirling engine based on the Franchot engine has novel cylindrical fins working as isothermalisers to improve the heat transfer without the complications of the heat exchangers. Enhancing the power density by isothermalising work spaces is compared to the bare cylinder optimised by varying the phase angle. The theoretical analysis shows that both the adiabatic and isothermal fins increase the power and efficiency, achieving the Curzon and Ahlborn efficiency at the maximum power point. In comparison to the phase angle method, the finned engine resulted in much lower gas mass flow rate which leads to a reduction in the regenerator pumping and enthalpy losses. Thus the Stirling engine has the potential to be simple, cheap, efficient and power dense, and thus can be used effectively for different applications.
- Franchot engine
- double acting Stirling engine
- heat transfer
- phase angle