Design and Analysis of Exhaust Manifold for a Single-cylinder Internal Combustion Engine (ICE)

Abstract

An efficient exhaust system is vital to maximising the performance of an internal combustion engine (ICE), hence improving overall vehicle performance. To have an efficient exhaust system, the amount of exhaust backpressure is to be minimised. To decrease the backpressure effects in the exhaust system, the exhaust has to be redesigned according to the certain bending radius, length of straight pipe and bending angle and pipe diameter. This paper presents design and analysis of the exhaust system used in Shell Eco-Marathon 2019 competition. In this project, the exhaust manifold was redesigned according to the specification of the chassis, the exhaust outlet in the engine and the rules and regulations of the competition. Computational Fluid Dynamic (CFD) analysis was employed to identify the optimum exhaust system design with minimum pressure loss. Among the tested models, the exhaust manifold with 100 mm length, 30° bending angle, 34 mm diameter, and 40 mm bending radius was the optimised design that resulted in the lowest pressure loss of 12.24 kPa. This study shows that a small bending angle with a short straight pipe has led to a smoother exhaust flow and even exhaust velocity across the model.