Small Auxiliary Lightweight Turbogenerator Engine (SALT-E)

Current VTOL UASs in development, and concepts being pursued by both commercial and military operators, require high-power delivery on takeoff and landing segments. This duty can be served with a special purpose ultra-lightweight gas turbine-alternator.ĀFor this short duty cycle, the relaxed SFC requirement opens opportunities for weight reduction strategies.ĀThis FOAÆs specification for electricĀpower/weight ratio of 2 hp/lb is extremely demanding, roughly twice that of BraytonÆs existing GT35 kWe recuperated microturbine alternator and about 4X that of commercial microturbines in this power class.ĀHowever, the SFC target is considerably more lenient.ĀUpon close inspection, meeting the NavyĀlightweight specification is not possible by simplifying dropping the recuperator from our GT35. Meeting the > 2 hp/lb specification requires a departure from conventional microturbine design formula.ĀWith heavy emphasis on weight over efficiency, BraytonÆs design adopts two foundational principles; maximize speed-power product for the alternator and maximize the turbine inlet temperature.