Thermal and Computational Fluid Dynamics (CFD) Analysis of a Modified Two Stroke Spark Ignition Engine Block

Abstract

An engine block is the main supporting structure for other components of the engine. Poor heat dissipation of the engine block causes excessive thermal expansion and frictional wearing of the engine components and makes engine oil to lose its lubricating power. Therefore, there is a need to modify the design of the engine block in order to improve its effectiveness. In this analysis, a two stroke spark ignition engine block was initially used as a reference model for the development of the modified model. Solidworks (2013) simulation software was used to model and conduct a thermal and computational fluid dynamics (CFD) analysis on the two models. The thermal analysis results shows that, the maximum temperature gradient and heat flux obtained during the steady state and transient thermal analysis were, 2.237×107𝐾/𝑚, 3.6817×104𝐾/𝑚, and 1.066×107𝑊/𝑚2, 1.661×106𝑊/𝑚2 for the reference model, while 1.771×106𝐾/𝑚, 4.913×104𝐾/𝑚, and 7.970×107𝑊/𝑚2, 2.211×106𝑊/𝑚2 for the modified model respectively. The results shows that the modified model has an improved heat dissipation rate than the reference model. The CFD analysis shows that, the reference model is subjected to high pressure and air resistance than the modified model. This increases the drag force acting on the reference model. While the modified model has high air flow velocity round the engine block, than the reference model. This is due to fins modification of the modified model. This makes the engine block model to have low air restriction. It is hereby recommended that further validation should be carried out to ascertain the effectiveness of the modified model. The performance of the modified model can also be improved by converting its fins into triangular fins geometry.