In the present paper CFD based investigation has been reported in order to study the effect of change in geometry\r\nof canopy on velocity and temperature on inside of canopy. It has been observed that there is significant change\r\ntemperature air flow, velocity inside the canopy. As the performance of fan is directly dependent on mass flow output. So\r\nthere should be a moderate velocity and temperature profile as all these parameters are co-related. In order to predict the air\r\nflow at inlet and output and temperature in canopy, analysis is done using a 3-D CFD software and to create a general idea\r\nabout a canopy, a model is created using a modelling software. Diesel engine generator sets in heavy industry plants and\r\nresidential/official buildings can cause serious noise problems. Diesel generators are used very commonly in shops, offices\r\nand in industry during power shut downs. The work is aimed at optimization of noise and thermal parameters of generator\r\nset. This paper focuses on air flow through canopy. Behaviour of air inside the canopy moving over inside parts of genset.\r\nEffect of air on inside cooling of canopy and thermal analysis of canopy done in this paper. Aim of this work, thermal\r\noptimization of canopy and effect of various design on overall parameters of genset. For such work position of baffle\r\nplate,louver angle with various design simulated in 3-D CFD software. Their results discussed in this paper. By using these\r\nsimulation work generator set can be examined and it gives way for investigation the different parts of genset.