Study of friction characteristics of a diesel engine running on different viscosity grade engine oils using conventional and acoustic emissions technique

Experimental studies were conducted on an off highway heavy duty diesel engine running on different viscosity grade engine oil, for determining the friction power in a firing engine by measuring the indicated mean effective pressure (IMEP) by in–cylinder pressure sensor and calculating the Indicated power and Brake power. It is known fact that hydrodynamic friction is related to the viscosity of engine oil and it has been shown that this friction can be reduced by using low viscosity grade engine oil [1]. Experimental results of friction power are compared with the novel use of non-intrusive acoustic emission (AE) technique to provide information pertaining to engine friction. Conventional method of friction assessment revealed that there is some improvement in reducing engine friction power when lower viscosity grade engine oil is used in place of recommended grade viscosity oil. These findings were corroborated with the modern AE technique which also indicated the benefits of using lower viscosity grade engine oil in reducing the friction. This paper will extend the scope of AE technique for analyzing friction of an engine and may provide an opportunity for inservice monitoring of efficient engine operation.