Computational and experimental determination of acoustic impedance of the exhaust system of an internal combustion engine

Abstract

The article presents the results of computational and experimental studies of acoustic impedance of the exhaust system of an internal combustion engine. The modern exhaust system consists of a "hot" and a "cold" part. The elements that are fixed to the engine and are part of it: the exhaust manifold, the turbocharger and the neutralization system are called the "hot" part. The second part, which contains elements to reduce exhaust noise (mufflers, resonators), is the "cold" part. Modern software allows to design the "cold" part with sufficient accuracy in a given geometry and in a given frequency range, but with the condition of accurately specifying the input parameters, namely, the amplitude spectrum of the input noise and the acoustic impedance of the noise source in the form of a motor with a "hot" part. The aim of the work is to obtain the most reliable acoustic output parameters of the "hot" part of an engine based on experimental studies on a non-motorized acoustic installation and computational studies by the finite element method using accurate 3D models of elements of the "hot" part.