An Analysis on the Thermal Flow Characteristics of the Car Exhaust Manifold Geometry

Abstract The exhaust manifold is connected to the engine cylinder block and concentrates the exhaust from each cylinder into the exhaust manifold with divergent piping. Research on how the stability and efficiency of the exhaust manifold affects the aftertreatment system of an automobile is actively conducted. Therefore, this article studies to derive the most suitable model for the design of the exhaust manifold of an automobile by analyzing and comparing its pressure distribution, flow distribution, and temperature distribution according to the different shapes of the exhaust manifold. The thermal characteristics were studied and analyzed using FLUENT in ANSYS 2019R3. The results of the analysis are as follows, based on the results of the comparative analysis of the pressure distribution, case 1 shows a low-pressure difference of 200 Pa. In the results of the analysis of the flow rate, the flow rate fluctuations are confirmed in cases 3, 2 and 1 in sequence. Furthermore, when the temperature distribution was analyzed comparatively, it was found that the shape of the car exhaust manifold did not have an effect on the temperature. Therefore, as a result of these findings, the Case 1 model was inferred to be the most suitable model for the design of the exhaust manifold shape of the automobile.