Effect of Confluence Geometry of Dual Exhaust System on Quietness and Power

Recently, the driving performance that maximizes driving pleasure, exhaust sound quality, and quietness have been recognized as important elements according to the demands of clients. Technology has been dramatically developed while the evaluation and improvement of the exhaust system have been attempted using various methods to meet the requirements of clients, the largest problem in designing the exhaust system is to maximize performance by forming the optimal back pressure and flow velocity and to reduce the generated noise and vibration. The objective of this study is to propose an optimal geometry of an exhaust system for sports sedans with a V6 and above engine. To achieve this, an experiment was conducted as follows. Before a prototype was fabricated, an exhaust system was designed and the fluid flow was analyzed. A pressure transducer was installed in the prototype, and the exhaust pressures on the exhaust system were measured at idle, medium and high engine speeds. Noise and vibration were also measured to analyze the impact of confluence geometry on the silence of vehicle. Finally, wheel horsepower, torque from wheels were analyzed using a chassis dynamometer to identify an output difference according to confluence chamber geometry and propose an optimal geometry.