Improving Fuel Economy of Commercial Vehicle by Introducing Optimized Electro-Magnetically Coupled Fan Drive

Increasing fuel cost and constant pressure to maximize the fuel economy are forcing OEMs in India to look for alternate engine cooling mechanism which will minimize the power take off from the engine without affecting the system reliability. Aim of this paper is to analyze the potential benefit of incorporating Electro-magnetic fan (EMF) drive in terms of fuel economy and reduced load on the engine. These benefits were compared with the conventional viscous coupled fan drive system. In vehicle with viscous coupling, fan RPM is based on the ram air temperature at coupling face which takes heat from turbo-charged air and coolant. On the other hand, EMF drive have a separate controller and control the fan RPM based on the coolant temperature enabling itself to respond directly to changes in the heat load as compared to viscous coupling having indirect representation of Coolant/charged air temperature. In this paper we have discussed about the optimization of size and speed of Electro-magnetic cooling fan to obtain the best achievable Fuel Economy. To validate the results testing was done on engines with different power rating and results were discussed along with the cost implication of introducing EMF Drive.