Description: Hybrid electric distributed propulsion (HEDP) systems have proven worthy for further consideration by approaching NASA's goals for N+2 and N+3 energy consumption, noise, emission and field length. The thermal management associated with these systems has been recognized as a major challenge to be overcome. ESAero's recent 2012 Phase I SBIR (NNX13CC24P) identified the radiator as a driving component within the thermal management system (TMS). Its design has profound first order effects on the weight, performance, and aerodynamic drag of the TMS, and second order effects on the weight and performance of the overall propulsion system. During the proposed Phase I SBIR, ESAero will upgrade the existing physics-based radiator design, analysis, and weight estimation conceptual design tool by improving the flexibility and fidelity of thermodynamic analysis and predicting the effects of integrating the radiator core within a well-designed duct. ESAero will call upon existing techniques to design a robust tool that more accurately predicts the "as-built" behavior of the component. These modifications are expected to dramatically improve the predicted weight and performance of the radiator and negate nearly all of the radiator drag by employing the Meredith Effect, as seen on the P-51 Mustang.

Benefits: This tool itself is part of a larger MDAO framework for hybrid-electric synthesis, benefitting multiple NRA projects and other direct NASA efforts both internal and external. This effort further chips away at the various nuances native to hybrid-electric distributed propulsion (HEDP) configurations by developing a sense of how distributed propulsion relates to thermal requirements. By developing conceptual design tools that are sensitive to coupled relationships between multiple disciplines, faster design cycles with increased depth and breadth of detail can be achieved. This module can be utilized by other tools written in the MATLAB language as it is capable of operating independent of the framework, thus allowing it to support non-HEDP aircraft designs as well. Phase II options include full HEDP integration studies including TMS considerations and potentially integrating these components and features into OpenVSP to create a more comprehensive conceptual design tool for HEDP.

As with ESAero's other conceptual design tools, the obvious commercial application of the improved radiator module is to use it and the TOGW framework it is associated with to support conceptual design groups in their research and development of hybrid-electric distributed propulsion (HEDP) aircraft. The tool may be used to guide aerospace primes and AFRL toward the identification of feasible HEDP architectures and support component manufacturers who are interested in how their technology would affect the leading edge in HEDP design and performance. AFRL would benefit as they are conducting in-house studies and supporting ESAero in other related areas. IARPA and the FAA will also benefit, as the tool will be distributed within the government FOUO. ESAero has indentified the government and industry partners to develop this type of technology near term (Boeing, General Electric, Lockheed Martin) and longer (NASA, AFRL, IARPA etc).