Description: As HEDP systems have proven worthy of further consideration by approaching NASA's goals for N+2 and N+3 energy consumption, noise, emission and field length, conceptual design tools to expedite the design cycle are desired. During this Phase I effort ESAero will progress the development of the hybrid-electric distributed propulsion (HEDP) TOGW tool developed in the previous Phase I SBIR (NNX13CC24P) by producing a physics-based wing structure analysis and weight estimation module. The layout of the structural members will be estimated using heuristic trends and top-level design assumptions, and the members will be sized according to classical beam theory. The interaction between HEDP configuration and aircraft weight is important to understand, as one primary advantage of the configuration is the ability to place smaller propulsors at virtually any location on the aircraft, leveraging pre-existing airframe supports. By delving into the structural analysis of HEDP designs, progress can be made toward determining how sensitive aircraft structural weight is to propulsion configuration. This new module will replace the modified, empirically based equations used in the current TOGW framework. By incorporating this capability, the novel architectures and configurations of HEDP systems, as well as other advanced aircraft concepts, could be analyzed and sized with greater fidelity. Furthermore, this effort may start to unravel concerns over other structural members paving the way for further investigation in a Phase II. Other potential Phase II tasks may include integrating this structural analysis and weight estimation into other conceptual design tools, such as OpenVSP.

Benefits: The potential NASA applications for this proposed effort will focus on integrating this module into the TOGW framework developed in ESAero's 2012 Phase I SBIR (NNX13CC24P). The 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, developing some sense of how distributed propulsion effects structural weight. These new hurdles have not been addressed in previous textbook methods or efforts, but play a significant role in determining the feasibility of these new aircraft configurations. As one of the major benefits to a decoupled energy management system is the freedom of placing propulsors, this tool would show, with higher fidelity, how sensitive wing weight structure is to that distributive freedom. The wing weight module can be utilized by other tools written in the MATLAB language as it is capable of operating independent of the TOGW framework. In Phase II work, more of the structural group could be studied to show similar sensitivities to hybrid-electric architectures, and the tool could potentially be integrated into OpenVSP, creating a more comprehensive conceptual design tool for HEDP.

As with ESAero's other conceptual design tools, the obvious commercial application of this wing structural weight 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. This tool will be among the first conceptual design tools to study the effects of propulsion system integration options on structural design and weight. The tool may be used to guide aerospace primes and AFRL toward the identification of feasible HEDP configurations 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).