Potential improvement in performance and emissions of air-cooled rotary engine using novel enhanced cooling fins

Abstract

The Wankel rotary engine (WRE) is widely used in the fields of unmanned aerial vehicles and range extenders due to its superior power-to-weight ratio. However, the rotor piston bears an intense thermal load during operation. This study focuses on the implementation of the coupled 1D-3D model. The influence of ECFs on WRE performance characteristics and emissions and improving WRE performance characteristics and emissions at different operating parameters (speeds and hydrogen enrichment) with ECFs are studied. The simulation results demonstrated that radial-fins have a more significant effect, reducing the fire-face's average temperature by 49.03 K and increasing the in-cylinder mass by 6.4 %. Compared with no-fins, radial-fins can increase pressure by 4.4 % and HRR by 5.6 %. At the same time, the NOx is reduced by 15.60 %, and the CO is slightly increased by 0.93 %. At different speeds, the ECF structure can improve the engine performance. The ECFs are more evident at low speeds, which can increase the indicated power by 3.13 % compared with the original engine. Compared with the gasoline-fueled WREs, using radial-fins can lead to more apparent performance improvement for hydrogen-enriched WREs. This paper will provide insight into the feasibility of ECF configuration to improve the performance of WREs in engineering applications.