Skip to main content
NASA Advanced Supercomputing (NAS) Division World-class modeling, simulation, and supercomputing in support of the NASA mission

Predicting High-Lift Aerodynamics on NASA Common Research Model - Part II: Delayed Detached Eddy Simulations

AMS Seminar Series

Speaker: Oliver Browne, Science and Technology Corporation, NASA Ames Research Center

Presentation

Seminar Slide Deck (PDF-13.6MB)

Abstract

An assessment of a Hybrid Reynolds Averaged Navier-Stokes (RANS)/Large Eddy Simulations (LES) {HRLES} approach for CLmax prediction, utilizing the Launch, Ascent, and Vehicle Aerodynamics (LAVA) solver, is presented for the NASA high-Lift Common Research Model (CRM-HL). Both the free air and the wind tunnel configuration of the CRM-HL are investigated, and the results are compared to the QinetiQ wind tunnel experiments and to two other numerical approaches: RANS and Wall-Modeled Large Eddy Simulations (WMLES). For the free-air configuration, HRLES was shown to address some of the known shortcomings in RANS methods and prevent inboard and outboard flow separation particularly in the region of CLmax and post-stall. To achieve these improvements over RANS, LES-appropriate grids and numerical discretizations are required. HRLES predicts a weak pitch break at the highest angle-of-attack due to onset of wing-root corner flow separation whereas the free-air corrected experiment values indicate an occurrence of a much stronger pitch break. The improvements of HRLES over Unsteady RANS approach has been objectively shown by computing a set of solutions with the same grid, same numerics and time-step size and comparing the solutions. It was also found that when applying HRLES to a RANS best practice grid and numerics that the HRLES method significantly underperformed RANS. For the in-tunnel configuration, HRLES showed good agreement with the loads, surface pressure and oil-flow photographs obtained in the experiment. HRLES was able to improve upon the RANS simulations, which showed a sharp loss of lift at the two highest angles-of-attack due to large scale inboard and outboard separation on the wing, by correctly predicting the corner flow separation and showing remarkably close agreement in the flow topologies with the experiment.

Funded by the Transformational Tools and Technologies (T3) project under the NASA Aeronautics Research Mission Directorate's Transformative Aeronautics Concepts Program (TACP).

Biography

Photo of Oliver Browne
Oliver Browne is a Research Scientist at NASA's Ames Research Center in the Launch, Ascent, and Vehicle Aerodynamics (LAVA) group within the Computational Aerosciences Branch. He received his B.Eng. degree in Aerospace Engineering from Coventry University (UK) in 2011 and his M.Sc. in Aeronautics from Imperial College London (UK) in 2012. He received his Ph.D. in Aerospace Engineering from Universidad Politécnica de Madrid (Spain) in May 2016. From September 2016 until September 2020, he was a Postdoctoral Research Associate at the University of Arizona and University of Kentucky working on various projects related to developing numerical methods for hypersonic boundary-layer transition prediction. In September 2020, Oliver joined the LAVA group at NASA Ames where his work has focused on research (code development and applications) into turbulence modeling, in particular Hybrid RANS/LES, which has included working on the High Lift Prediction Workshop 4 (HLPW4) and Transonic Truss-Based Wing (TTBW) projects.