CFD Analysis of Axial Flow Fans for Radiator Cooling in Automobile Engines 2007-01-4262

Radiators are installed in automobiles to remove heat from the coolant. The use of higher output engines with tightly compacted under hood packaging, the addition of new emission components, and aerodynamic front end styling with narrower openings are creating a hostile thermal environment in the engine compartment. This results in a smaller volume of under hood cooling air. So, to handle higher volume flow rates of air axial flow fans are used to cool the radiators. These fans consume considerable amount of power from the engine and hence the performance of the axial flow fan is an important parameter of the efficiency of the engine cooling system. CFD is used as a major design tool to investigate major issues related to the performance of fan, like volume flow rate and static pressure rise etc. The present work investigates the characteristics of the flow over axial flow fans, which are used for radiator cooling, using CFD code FLUENT 6.0. Comparison between CFD simulation and results from Blade Element Theory of two typical commercial axial flow fans with different blade profiles are presented. It is noticed that the fan efficiency can be improved by a fixed ring at the fan tip which avoids the back flow from casing. The heat from the engine coolant can be converted into work using an Axial-flow turbine before entering the radiator.