N221-004 TITLE: DIGITAL ENGINEERING - Embedded Aircraft Design Geometry in Multidisciplinary Design Optimization Frameworks

OUSD (R&E) MODERNIZATION PRIORITY: Hypersonics

TECHNOLOGY AREA(S): Air Platforms

OBJECTIVE: Develop and demonstrate a conceptual design geometry tool capable of embedding in fixed- and rotary-wing multidisciplinary optimization frameworks to enable improved estimates of cost and technical feasibility during requirements development and concept refinement of new manned aircraft, unmanned aircraft systems, and weapons.

DESCRIPTION: Early in the acquisition lifecycle of a new air vehicle�Pre-milestone A�the Department of Defense (DoD) conducts aircraft conceptual design studies to determine the technical feasibility of potential requirements sets. The DoD uses these conceptual designs to estimate the development, production, and operating cost of the aircraft program. They also use the designs as inputs to virtual and constructive modeling and simulation (M & S) tools. The DoD uses M & S to quantify the military effectiveness of the aircraft design. Finally, the DoD uses this combination of cost vs. effectiveness data as the basis for decisions setting the requirements for the new aircraft development program.

This process can be used for all sizes and types of air vehicles, from manned tactical aircraft like strike fighters, to rotary-wing vehicles like helicopters and tilt-rotors, to small unmanned aircraft and weapons. This forms the start of the Model-Based System Engineering (MBSE) process. At Naval Air Warfare Center Aircraft Division (NAWCAD), this process is conducted by the Mission Engineering and Analysis Department (MEAD). MEAD engineers use multidisciplinary analysis and optimization (MDAO) software frameworks to find the best possible design for each potential requirement set under evaluation.

This current process is significantly hampered by the lack of a 3D aircraft geometry modeling tool that can be embedded within MDAO frameworks. MEAD engineers need an ability to visualize the geometry they are entering into the MDAO framework in order to support program offices as they look at new and innovative air vehicles, from hypersonic weapons to manned rotary-wing platforms to Unmanned Aerial Vehicles (UAVs) designed specifically for manned-unmanned-teaming. They also need the ability to generate 3D models of the aircraft results produced by the MDAO framework. Currently, commercial CAD packages are not flexible enough to handle the large variations in geometry produced during an MDAO run. Some open source parametric geometry tools are flexible enough, but do not allow the Application Programming Interface (API) to be used while the Graphical User Interface (GUI) is open.

This geometry modeling tool must allow parametric modeling of a wide variety of classes of aircraft and nonconventional arrangements. It should include an aircraft conceptual design specific geometry parametrization, and provide a fully documented, fully unit tested API that allows communication with MDAO software while the geometry tool GUI is open. It must include a GUI that enables MEAD and program office engineers to visualize geometry as they input it to MDAO software, and as the MDAO software returns results. The geometry tool should provide the flexibility to easily generate new aircraft configurations, with the capability for an engineer to start from a blank file and create all major aircraft components in less than one hour. All features available in the API should be available in the GUI, and all features available in the GUI should be available in the API. It must be capable of generating multiple geometry models for analysis from a single authoritative model, including the ability to generate geometry input data for Vortex Lattice aerodynamic analysis. It should be capable of modeling both fixed-and rotary-wing vehicle geometries. It must be capable of exporting 3D watertight trimmed geometry models in both IGES and STEP formats. It must be capable of modeling internal component layouts and outer mold line geometry shapes. It should be capable of providing geometry measurements including surface areas, volumes, cross sectional areas, and projected areas. It should be capable of running on both Windows and Linux operating systems.

PHASE I: Demonstrate the feasibility of an aircraft geometry modeling tool that can be embedded in an MDAO framework. This demonstration will test integration with both the Aircraft Design, Analysis, Performance, and Tradespace (ADAPT) framework produced by the DoD High Performance Computing Modernization Program (HPCMP), and with An Integrated Design Environment for NASA Design and Analysis of Rotorcraft (AIDEN/NDARC). The government will provide access to both ADAPT and AIDEN for development and demonstration. The demonstration of at least one feature in the API working while the GUI is open, providing two-way communication between the geometry tool and ADAPT is a critical goal of Phase I. The demonstration of two-way communication between the geometry tool and both AIDEN is also a critical goal of Phase I. The Phase I effort will include prototype plans to be developed under Phase II.

PHASE II: Develop a prototype fully featured geometry tool, with all capabilities available within the API while the GUI is running. Direct integration with both ADAPT and AIDEN frameworks should be completed. Several classes of military aircraft should be demonstrated (fighters, helicopters, hypersonic weapons, small unmanned aircraft, etc.). GUI updates to support integration with MDAO frameworks must be completed. Documentation and unit testing of the full API will be completed.

PHASE III DUAL USE APPLICATIONS: Final integration tests with MDAO frameworks will be completed, and the geometry tool will transition into use with NAWCAD MEAD engineers, and other design groups in government and industry.

Geometry modeling for aircraft conceptual design is needed across industry for both defense and commercial applications. A geometry tool capable of direct integration with MDAO frameworks could be valuable to many private sector design groups.

REFERENCES:

1. McDonald, R. (2016). Advanced Modeling in OpenVSP. 16th AIAA Aviation Technology, Integration, and Operations Conference. https://doi.org/10.2514/6.2016-3282.
2. Gary, A. & McDonald, R. (2015). Parametric Identification of Surface Regions in OpenVSP for Improved Engineering Analysis. 53rd AIAA Aerospace Sciences Meeting. https://doi.org/10.2514/6.2015-1016.

KEYWORDS: Aircraft Design; Geometry; Optimization; MDAO; Software; Open Vehicle Sketch Pad; OpenVSP