A review on the correlation between exhaust backpressure and the performance of IC engine

Abstract

The exhaust system in any Internal Combustion (IC) engine is a critical component that affects the engine’s performance. A poorly designed exhaust system generally results in an increment of exhaust backpressure. Backpressure is one of the fluid’s characteristics that acts as a resistance to exhaust gas flow. Relatively higher backpressure blocks the exhaust gas flow from discharging efficiently, decreasing the engine’s performance. In general, higher backpressure results in power and torque loss as well as higher fuel consumption and emission to the environment. This review paper aims to elucidate the relationship between exhaust backpressure and the performance of IC engine. Various past studies were conducted to study the effect of exhaust backpressure on the performance of IC engine through Computational Fluid Dynamic (CFD) simulation, engine simulation and experimental analysis. Some studies used Taguchi’s method to optimize the exhaust manifold’s design in respect to backpressure decrement. It was found that 0.22 kW to 0.45 kW of engine’s power increases for every 1 kPa of exhaust backpressure decrement. At the same time, 1.5% to 3% of fuel consumption decreases for every 10 kPa of backpressure decrement. In contrast, higher backpressure does reduce the Nitrous Oxides (NOx) emission in the exhaust gas due to higher temperature. Therefore, exhaust backpressure must be minimized to improve any IC engine’s performance if the NOx emission is neglected. This review paper is expected to provide a better understanding of the impact of exhaust backpressure on IC engine’s performance.