Shape Design Thermal Improvement of the Exhaust Manifold

Abstract

The exhaust manifold is the bridge connecting the cylinder head to the catalytic converter, which collects the exhaust gases from the multiple cylinders and sends them to one pipe exhaust. The temperature of the exhaust gases in the manifold reaches so high as 800 °C. So, the exhaust manifold is affected by thermal loading due to the high-temperature gradient. This paper presents a numerical and experimental analysis implemented a typical cast iron exhaust manifold. In this study, the temperature extracted from the manifold done by employing different shape types of longitudinal fin mounted on the external surface of the manifold. In the numerical analysis, the model generated by Solidworks software firstly and simulated using ANSYS Workbench R19 for different cases. The experimental work adopted two best numerical modelling results, which have been selected for fabrication and testing experimentally. Results found that the effect of fin installation gives a better reduction in the surface temperature along the exhaust manifold, especially in the high thermal loaded middle section, where the temperature drops to more than 100 ℃. Also, the Sinusoidal fin model achieved slightly better results than the straight model despite the small surface area. Moreover, the comparison between the numerical and experimental works gives a good matching reached 1.8%, which is assisting the numerical analysis.