Tradictionally, intake noise has not received nearly as much attention as exhaust noise. but nowadays, intake noise from internal combustion engine is a major contributing factor to automotive passenger compartment noise levels.
In this study, compressible Navier-Stokes eqns are employed numerically for the intake stroke of axisymmetric model having a single cylinder and a single intake valve.
The main objective of this paper is to identify the mechanism of gerneration, prorpgation and radiation of the intake noise. The main noise source for the intake stroke was found to be the pressure surge which is gernerated after intake valve closed. The pressure surge which has the nonlinear acoustic behavior propagates and radiates without attenuation easily.
To simulate the periodic motion of the piston and valve, unsteady deforming mesh algorithem is employed and Thompson's non-reflecting boundary condition is applied to the radiation field.
In order to resolve the small amplitude waves at the radiation field, essentially non-oscillating(ENO) sheme with artificial compression method(ACM) are used