Thermal and mechanical performance analysis of a Wankel engine with outer body from new generation composites

In this study, thermal and mechanical performance analyses have been conducted by constructing 3D modelling of an existing Wankel engine. In case the cooling systems of the current engine are disabled, the temperature increase and thermal expansion of the engine housing have been investigated numerically. It is assumed that the crankshaft rotates at a speed of 6000 rpm. In addition, combustion is supposed to occur stoichiometrically. Transient changes of the volume and surface area depending on the crankshaft angle has been calculated using SOLIDWORKS software. After that, the current engine has been modelled using GT-SUITE software which is a one dimensional engine design and simulation tool. For one dimensional analyses, firstly geometric and dynamic similarity rules of a standard 4-stroke engine have been applied to the Wankel engine. The results obtained are compatible with that of the studies on this topic in the literature. After that, 3-dimensional analyses have been conducted to investigate the thermal and mechanical performance results in detail. For this purpose, ANSYS software has been utilized and the engine model has been prepared for the 3D analyses. Heat flow, heat conductivity coefficient and temperature variables obtained from GT-SUITE program are defined in the Ansys program as the initial conditions for the transient simulations. The calculation time of the engine is determined as 2700 seconds and the crankshaft rotation speed is kept constant at 6000 rpm. Temperature difference of 98.34 °C is obtained in the engine model with the aluminium housing from the simulations. Also, expansion of 0.609 mm is obtained on the inner surface of the body, where the rings contacted. These results are logical and compatible with the data we have obtained in our literature review. Due to this study, it is estimated that cooling system models of Wankel engines can be developed and analysed at the design stage.