Panuwat Chanmak.. Development of an exhaust noise simulator for internal combustion engines. Master's Degree(Automotive Engineering (International Program)). King Mongkut's University of Technology North Bangkok. Central Library. : King Mongkut's University of Technology North Bangkok, 2008.
Development of an exhaust noise simulator for internal combustion engines
Abstract:
This thesis designs and constructs a simulator for producing engine's exhaust noise. The simulator allows engineers to test new developed silencers without being concerned about the hot and pollution environment; especially with the test that must be carried out in an anechoic room. The simulator developed in the thesis is built using a 1-cylinder, 4-cycle, 100-cc Honda engine. The piston is fixed at its bottom dead center (BDC). The cam mechanism of the engine block is driven by a DC motor. The noise is generated by compressed air, which replaces the hot exhaust gases. The compressed air from the supply network is charged into the cylinder when the intake valve opens. After that, when the intake valve closes while the exhaust valve opens, the cylinder discharges the compressed air. This cycle generates a pressure pulse. For continuing the cycles, the pressure pulses from the simulator create similar exhaust noises as those of a real combustion engine. To validate the simulator, the noise spectrum generated by the simulator and a real engine are compared. All noise measurements are carried out inside an anechoic room. Comparative results illustrate a good agreement.