Strategy of the combustion process diagnosis in direct injection engines

The proper strategy of internal combustion engine operation is one of the basic aims being taken into account in a design process, in a phase of building the first design of a specified engine, verification of geometrical and operational parameters for a real object (comparing to a brief foredesign) to the moment when one obtains the final design of the engine. This particular purpose of such process is also important during combustion engine operation in a stationary or traction applications. Undoubtedly, the assessment of the main processes taking place in such engines, especially combustion processes runs, in the point of view of the correct diagnosis and engine operation management, is convergent with present and future combustion engines design trends and with the world environment protection requirements. That is why the paper concerns the assessment of a combustion process correctness in a direct injection compression-ignition engine on the basis of vibration signal runs and their digital processing. The method of such diagnosis was implemented to identify quality and quantity changes of main processes characteristics and diagnostic parameters regarding with engine work conditions, operation time and with some problems appearing in specified engine working cycles. The paper gives scientific solutions for precise diagnosis of combustion process correctness and some failures that could take place in combustion of compression-ignition and direct injection engines. Reliability of a method for these scientific tasks was checked for research conducted in stationary engine operation conditions. (C) 2014 The Authors. Published by Elsevier Ltd.