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A computerized thermodynamic analytical program is being developed to help investigate the impact of power system requirements on aircraft performance. The Visual Basic for Applications (VBA) program has a user interface that operates in MS-EXCEL, linking several subsystem analysis programs for execution and data transfer in the power systems analysis. The program presently includes an encoded propulsion engine cycle code, which allows the inspection of power extraction effects on engine performance. To validate the results of the encoded engine program, a study was conducted to investigate the separate effects of shaft power extraction and pneumatic bleed. The selected engine cycle was that for a standard tactical fighter, with a flight condition of varied altitude (sea level to 40k-ft.) and constant Mach Number(0.9). As expected, the resultant data showed that the engine performance was more sensitive to pneumatic bleed than to shaft power extraction.

The concept of a more electric aircraft has revolutionized the way aircraft and subsystems are being built. New components are also proving to be more efficient, resulting in the possibility of changing the way systems are cooled. Before these new concepts will be utilized, they must be evaluated to determine system level impacts. To aid in these evaluations, an engine model is developed, traditional cooling schemes system level impacts calculated, a boundary layer heat sink proposed, and several new technologies proposed for evaluation.

A cooling technique is devised which will maintain the electronics within their thermal operating limits when the power output of currently used VSCFs is augmented to 65 kVA from 40 kVA. This study suggests that the use of jet impingement cooling selectively applied in regions of high heat flux will support the enhancement in performance desired. Experiments were run to determine the forced convective cooling of the current VSCF design. Experiments were then run to determine the submerged jet impingement cooling characteristics. Finally a FEA numerical model of the SCR module mounted on the tube flange with forced convection and jet impingement cooling was set up. The FE analysis indicates that at 65 kVA submerged jet impingement cooling will mitigate the temperatures of the SCRs sufficiently to maintain them within their operating envelope.