Aircraft Power System Evaluations for a Solid State Laser Power Conversion Application

Abstract

General thermodynamic analytical evaluations were performed to investigate the impact of technological improvements on mission effectiveness, weapon power generation and size of an aircraft based high-energy laser power system. The Aircraft Electrical Laser (AEL) power system essentially consists of six major components, the prime power source, the power generator, the power conditioner, the laser system including the gain medium, the beam processor and the thermal management system (TMS). The prime power source was essentially a 180 kW power stream provided by the cargo aircraft, which served as the platform for the AEL power system. The analysis was based on a 100 kW power output solid state laser power system and a notional mission profile with an engagement period of 680 seconds during which several duty cycle scenarios were considered. The entire mission consisted of the potential prosecution of four clusters with four targets in each cluster. Two primary power system architectures were evaluated, a baseline AEL power system architecture with current state-of-the-art technologies for all components and an advanced power system architecture based on future technological improvements to each of the six components. The investigations were extended to determine the effects of diode operating temperature, temperature gradients within the diode, duty cycle variations and environmental considerations such as the type of day, on the the mass and volume of the overall power system. Preliminary analysis based on current technologies and anticipated advanced technologies in a decade revealed that the overall mass of the power system could be brought down by 35% from the baseline near-term architecture to the conceptual far-term architecture. The impacts of diode operating temperature, diode temperature gradient, duty cycle (DC) and environmental conditions on the overall mass of the AEL power system for near-term operation, were evaluated. The general trend observed in most cases, was an increase in the mass of the TMS with a subsequent increase in the overall power system mass. There were several situations where the Ram Air Heat Exchanger (RAHX) could not handle the entire heat load and so thermal energy storage cells were designed to augment the RAHX to accommodate the total heat loads.