Abstract
Operational Transfer Path Analysis (OTPA) is applied to a noise source contribution analysis for high thermal efficiency diesel engines. However, vibrations are transferred in an engine body by structure-borne, reference signals for OTPA are desired to contain assumed noise source components mainly. This paper describes some innovations which are tried to extract the desired components from the reference signals. In addition, this paper shows a mechanical noise prediction technique which combined OTPA and an empirical formula based on a vertical force of inertia and validation results by an engine test with reciprocating mass variations.
