Currently, the variable speed constant frequency generators (VSCFG) developed at Leland Electrosystems, Inc., provide approximately 40 with the introduction of the More Electric Aircraft (MEA), the dem on the generator will rise to 65 KVA and above. The current limit 40 KVA on the genertor is partially due to the fact that the temperature on the SCR modules (used for switching high current) is the design li,it. This is because currently, heat is removed by fo convection, the oil being made to flow over the entire internal ann cavity of the generator. In regions where the SCRs are mounted the cool oil will absorb heat. However, in regions where no heat sourc exist, the cooling capability of theoil is not taken advantage of. However, if syrayjet impingement cooling were selectivly applied it advantage of the total cooling capacity of the coolant; it would support higher heat flux rates (25 time higher); and allow the SCR devices to be run harder. This is because the higher heat-transfer coefficintt will lead to a lower temperature drop for the same heat flux. This study proposes to apply selective jet-spray impinge cooling on the Leland VSCFG, analyze the heat transfer and flow characteristics using finite element methods (FEM, e.g. ANSYS. I-DEA NISA), and prove that the cooling performance of the system and hen the electrical power output can be substantially enhanced.
Keywords: JET SPRAY IMPINGEMENT COOLING POWER ELECTRONICS GENERATORS
