Low Noise Axial Fan Optimization for the Marine Corps Expeditionary Fighting Vehicle

The Marine Corps Expeditionary Fighting Vehicle (EFV) experiences excessive air handling unit noise and the cooling fan does not meet the requirements that have been established for its operation. During the past fifteen years, substantial progress has been made in noise mitigation through the use of computational fluid mechanics (CFD). In particular, the automotive industry has invested millions of dollars in engine cooling systems in order to provide more quiet fans that will go in their automobiles. A major technique that has been applied to the rotating blades of fan systems in order to suppress noise is the technique of “sweeping” the blades. MSI proposes to use a swept rotor blade in order to suppress the noise of the EFV fan. In order to maximize prototype development, MSI will utilize new aero-acoustic software that when coupled to CFD will predict the sound levels produced by a rotating blade row. Traditionally, designs have been performed using CFD and FEA, and then been subjected to experimentation. MSI will use the aero-acoustic software to minimize fan noise along with specialized sound pressure level field testing to back up and confirm the analysis results.