Karem Hybrid Turbo-Electric Optimization

Karem Aircraft has been developing advanced, highly efficient tiltrotor aircraft for over 15 years and has explored multiple options for implementing partial or fully electric propulsion systems. While in many cases it is feasible to electrify aircraft propulsion, there are many tradeoffs, and we believe it is critically important to understand when it is and is not an optimal solution. Hybrid configurations can provide many benefits however, detailed analysis is required to appropriately size the various elements of the propulsion system – liquid fuel stores, engine, motor/generator, battery storage system, transmissions/gearboxes – to optimize the design. While designers can achieve a net performance benefit, it often comes with increased system complexity and operating weight empty (OWE). If not properly designed, the resulting electrified aircraft is less capable from a payload, range, and endurance perspective than a comparable conventionally powered variant. The state of technology today offers the opportunity to improve aircraft mission performance by conducting the detailed analysis required and augmenting conventional powerplants with optimally sized hybrid electric systems Karem will work closely with the Government to determine which performance parameters should be prioritized for optimization in order to maximize mission capability. With that information, Karem plans to achieve the following technical objectives in this study:   Fully develop and explore the trade space of the various components of a hybrid turbo-electric aircraft propulsion system. Compare parallel and distributed electric hybrid configurations for a given air vehicle. Determine the optimal configuration(s) to maximize the Government’s desired mission performance capabilities such as maximum takeoff weight, maximum hover out of ground effect (HOGE) weight at various ambient conditions, airspeed at maximum continuous power (Vmax), maximum range, and maximum endurance. Coordinate with the Government to develop one or more operationally relevant mission profiles. Determine the optimal hybrid configuration to maximize aircraft performance on those mission profiles. Analyze the cost/benefit of the various configurations based on mission performance and anticipated system cost, reliability, maintainability, and supportability.