Evaluation through pressure and mass velocity distributions of the linear acoustical description of I.C. engine exhaust systems

摘要

Linear acoustic theory is still the most widely used tool for exhaust system design in I.C. engines. In this paper, the pressure and mass velocity distributions along hte exhaust system are used to evaluate the results from linear acoustic thoery. These results are compared with those obtained from a full non-linear calculation validated against engine test experimebts. The analysis performd allows the influence of two relevant aspects to be separated: the linear representation of the source (engine and manifold) and the linear description of the exhaust system itselft. The results indicate that good qualitative agreement may be attanined in general, but some differences associated with non-linear effects can appear.