A study on pressure drop and heat transfer in open cell metal foams for jet engine applications

This research investigated the feasibility of placing a ring of open cell metal foam between the combustor and the turbine section of a turbojet engine to homogenize the temperatures leaving the combustor to raise the overall efficiency of such engines. Heat transfer testing on Al foam samples was done using infrared imaging to test the foam's efficiency of mixing the hot and cool temperatures with very promising results (21% and 37% mixing factor in a 10 cm thick layer of 5 and 10 PPI foam, respectively). Pressure drop testing on Al foam was also done in the compressible region of air to investigate the loss of pressure through the foam. The tests concluded that when temperature effects where accounted for, the pressure drop was less than 34.5 KPa per 2.54 cm of foam.