Projeto conceitual e análise de fluxo de um abafador valvulado

Abstract

In the automotive world, the noise emitted by the exhaust of combustion vehicles is of great importance in its design. It can be focused on performance, achieving more decibels and a freer flow, thereby improving the vehicle’s efficiency in sports cars. On the other hand, for everyday and family use, a muffled sound with fewer decibels is more desirable for the project. Considering this, the automotive industry, especially in high-performance vehicles, introduced the valved muffler, which is the topic of this work. The main benefit of this type of muffler is the alteration of the acoustic characteristics of the exhaust system with just the push of a button, completely changing the user’s experience with the vehicle. It makes a sports car more usable in daily life with the valves closed, reducing the emitted sound, or enhancing the sound by opening the valves, either for a specific event or for the auditory experience. The objective of this work is to carry out the conceptual design of a valved muffler with dimensions similar to conventional mufflers available in the market without this device. For this purpose, Siemens NX CAD software was used for the 3D design of the muffler, followed by the study of gas flows inside it. The results indicate that the use of an internal valve to alter the path of the exhaust gases can increase restriction when the valve is closed, reducing the vehicle’s sound. Conversely, when open, it allows for a free flow of gases, improving the vehicle’s performance and increasing the sound emitted by the exhaust system.