Theoretical and experimental investigation of the effect of perforated hole diameter, number of perforations and pipe diameter on back pressure in silencers

Exhaust silencers are used in cars and trucks, motorcycles, generators, watercraft, aircraft, construction and industrial equipment such as cranes and excavators, regardless of whether they are diesel or gasoline engines. The main purpose of these silencers is to reduce the high noise level from internal combustion engines and to ensure that exhaust gases can be discharged into the atmosphere. However, resistance elements such as sound absorbing materials, resonators and pipes used in exhaust systems restrict gas flow and create a high back pressure in the exhaust system. Due to the back pressure, the efficiency of the engine is reduced because the combusted gases cannot be freely exhausted. In this study, the parameters of perforation hole diameter, pipe diameter and number of holes affecting the backpressure formation in the exhaust system are investigated. In order to determine the effect of each parameter on back pressure, theoretical modeling and analysis were obtained using Solidworks Flow Simulation program. Exhaust back pressure experiments of the theoretically analyzed silencers were carried out with the test system in the R&D laboratory. Within the scope of the experimental studies, the data obtained by using silencer models with different geometric configurations are presented in detail using graphs, charts and figures. It is thought that the data and analysis obtained at the end of the study will provide important contributions to both manufacturers and researchers on the relationship between muffler design and exhaust back pressure.