The Meshing, Visualization and Computing Environments (MVCE) Technical Committee has been working to develop a priori mesh quality metrics. A recent session at the 50th AIAA Aerospace Sciences Meeting in Nashville, TN was held so members of the committee could present their findings. The session was well attended, confirming that most CFD practitioners consider mesh quality to be a major component of simulation accuracy. The findings indicate that several metrics have value in predicting mesh quality, but usually only within reduced application space. To learn more about the MVCE’s work in this area, start with the paper presented by Hugh Thornburg which summarizes the results of a MVCE grid quality workshop held in August 2011.
Another active topic for the MVCE committee is CAD requirements for simulation. A session was held including three invited talks followed by a panel discussion. Invited speaker Jan Vandenbrande of the Boeing Company presented Boeing’s approach to geometric modeling. Jan stated that an important obstacle to overcome is robust parametric geometry creation during design optimization. Jan showed examples where a geometric model would deviate from design intent (or even become degenerate) given certain combinations of design variables. Since design optimization is performed as an automated task, such problems often go unnoticed. It is also important that the parametric modeler constructs a design that is realizable during manufacture. The panel confirmed that, despite recent advances in CAD technology, work is still needed to develop a system which meets the needs of design, simulation, and manufacture adequately.
Aircraft design was also an active topic at the Aerospace Sciences Meeting this year and included discussions involving aircraft design tools, as well as, multidisciplinary design optimization. With design optimization becoming a hot topic for discussion, sessions focused on efficient optimization and rapid design parameterization techniques during the conceptual phase of aircraft design. Stanford Ph.D. candidate Mathias Wintzer presented an adjoint-based inverse design methodology for an aircraft with a low sonic boom signature. Mathias demonstrated that by using inverse design, target pressure signals could be realized using gradient-based optimization techniques. The framework involved coupling adjoint-based CFD to obtain the required objective function and surface sensitivities with gradient-based optimization and parametric design tools to drive the vehicle shape changes. The number of parameters and the quality of the shape deformation are highly dependent on the parameterization methods selected. Wu Li, a senior research engineer working at NASA Langley Research Center, presented rapid parameterization schemes used in aircraft design with a tool called PROTEUS. Applied to wing and body type surface components, Wu described a number of parameterization schemes supported by PROTEUS and demonstrated its setup and ease of use for common shape modifications.
When we were not attending technical committee meetings and technical sessions, we were set up in the Exhibition Hall demonstrating our meshing software, Pointwise. The Exhibition Hall was well populated by vendors across the spectrum of the aerospace industry. Notable hardware vendors included Lockheed Martin, Boeing, U.S. Air Force, U.S. Navy, General Electric, Raytheon, and Pratt & Whitney. Notable software vendors included ANSYS, CD-adapco, Intelligent Light, CEI, Tecplot, and Metacomp.
Be sure to stop by our booth next year at the 51st AIAA Aerospace Sciences Meeting January 7-10 in Grapevine, TX at the Gaylord Texan Resort and Convention Center. We look forward to seeing you there!