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In this paper, the effect of geometrical parameters of centrifugal fan on performance has been presented with a system approach. Often, the operators or the design engineers focus on the immediate requirements of the engine/equipment and they neglect the broader question of how the fan parameters are affecting the equipment. For instance, change in fan angles will change the performance e.g., airflow rates and efficiency. However, it also affects the contaminants build-up on the blades. Blade angle with higher angle of attack will promote contaminants build-up on blade surfaces, which in turn causes performance degradation and unstable operation. The system approach in fan parameter selection will result in a more reliable system. Significance of other fan parameters is also discussed. We present an experimental setup and validated computational fluid dynamic (CFD) model. Fan power consumption is determined experimentally and compared with the CFD model. Further parametric simulations were carried out to investigate the effect on fan performance. Effect of system resistance, inlet and outlet angle, blade thickness, and no-uniform spaced blades has been described with discussions on industrial relevance. A fan with higher flow rates is desirable to reduce engine temperatures and enhance the durability. However, higher flow rates result in more fan power consumption at a given fan speed. The test results suggest that a fan with higher power coefficient does not affect the vehicle's mileage significantly. This paper will help design engineers in making informed decision about the interaction between the fans and system, and its effect during the operation.

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The air-cooled engine surfaces are generally provided with extended surfaces of high conducting materials called fins for enhanced heat transfer. One way to increase the rate of heat transfer is by increasing the fins surface area. However, increase in fin length introduces undesirable vibrations of the fins, which in turn radiate annoying high frequency noise. With the demand of quieter engines increasing, the vehicle manufacturers follow counter measures to minimize the fin vibrations. One trend in the two-wheeler industry is to put rubber dampers between the fins. These rubber dampers damps out the level of vibrations and the level of noise radiated is reduced. However, these rubber dampers have many disadvantages. Apart from the adding extra cost and a parallel manufacture process, these rubbers act as an insulating material, which impede the free flow of cooling air. The engine may get overheated and purpose of providing extended surface would not be satisfied. In this paper, effect of these rubber dampers on engine radiated noise and thermal performance is investigated. We discuss a systematic methodology on how to remove these rubbers by keeping the noise level same along with higher heat transfer from the engine surfaces. Results from experiments and numerical simulations for noise & vibration and computation fluid dynamics (CFD) with conjugate heat transfer are discussed. This paper describes a classic example of multidisciplinary approach to solve real-world design problems.