The NASA tetrahedral unstructured software system (TetrUSS)

Frink, Neal T.; Pirzadeh, Shahyar; Parikh, Paresh; Pandya, Mohagna J.; Bhat, M. K.

doi:10.1017/s0001924000091995

Cited by 158 publications

(1 citation statement)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The spatial discretization in nominally second-order and it is part of TetrUSS (Tetrahedral Unstructured Software System). [24] The USM3D code uses advanced turbulence models [25] and second-order temporal schemes for unsteady flows. [26] Threepoint backward differencing and pseudo-time subiterations are used for time integration, which is referred to as Option-1 in Elmiligui, Abdol-Hamid, and Parlette.…”

Section: A Usm3dmentioning

confidence: 99%

F-16XL Hybrid Reynolds-Averaged Navier–Stokes/Large-Eddy Simulation on Unstructured Grids

Park

Abdol-Hamid

Elmiligui

2017

Journal of Aircraft

View full text Add to dashboard Cite

The Cranked Arrow Wing Aerodynamics Program, International (CAWAPI) investigation is continued with the FUN3D and USM3D flow solvers to fuse flight test, wind tunnel test, and simulation of swept wing aerodynamic features. Simulations of a low speed, high angle of attack condition are compared. Detached Eddy Simulation (DES), Modified Delayed Detached Eddy Simulation (MDDES), and the Spalart-Allmaras (SA) RANS model. Isosurfaces of Q criterion show the development of coherent primary and secondary vortices on the upper surface of the wing that spiral, burst, and commingle. Mean DES and MDDES pressures better predict the flight test measurements than SA model predictions, especially on the outer wing section. The USM3D simulations predicted many sharp tones in volume point pressure spectra with low broadband noise and The FUN3D simulations predicted more broadband noise with weaker tones. Spectra of the volume points near the outer wing leading-edge was primarily broadband for both codes. Time-averaged forces are very similar between FUN3D simulations and and similar between USM3D simulations, but FUN3D predicts slightly higher lift and lower drag than USM3D. There is more variation in the pitching moment predictions. Spectra of the unsteady forces and moment are mostly broadband for FUN3D and tonal for USM3D simulations.

show abstract

Section: A Usm3dmentioning

confidence: 99%

F-16XL Hybrid Reynolds-Averaged Navier–Stokes/Large-Eddy Simulation on Unstructured Grids

Park

Abdol-Hamid

Elmiligui

2017

Journal of Aircraft

View full text Add to dashboard Cite

show abstract

Iteration schemes for rapid post‐stall aerodynamic prediction of wings using a decambering approach

Paul

Gopalarathnam

2014

Numerical Methods in Fluids

View full text Add to dashboard Cite

SUMMARYNonlinear aerodynamics of wings may be evaluated using an iterative decambering approach. In this approach, the effect of flow separation due to stall at any wing section is modeled as an effective reduction in section camber. The approach uses a wing analysis method for potential‐flow calculations and viscous airfoil lift curves for the sections as input. The calculation procedure is implemented using a Newton–Raphson iteration to simultaneously satisfy the boundary condition, which comes from potential‐flow wing theory, and drive the sectional operating points toward their respective viscous lift curves, as required for convergence. Of particular interest in this research is the calculation of the residuals during the Newton iteration. Unlike a typical implementation of the Newton iteration, the residual calculation is not performed via a straightforward function evaluation, but rather by estimating the target operating points on the input viscous lift curves. Estimation of these target operating points depends on the assumptions made in the cross‐coupling of the decambering at the different sections. This paper presents four residual calculation schemes for the decambering approach. The residual calculation schemes are compared against each other to assess computational speed and robustness. Decambering results are also compared with higher‐order computational fluid dynamics (CFD) solutions for rectangular and swept wings. Results from the best scheme compare well with the CFD solutions for the rectangular wing, motivating further development of the method. Poor predictions for the swept wings are traced to spanwise propagation of separated flow at stall, highlighting the limitations of the current approach. Copyright © 2014 John Wiley & Sons, Ltd.

show abstract

A Survey of Free Software for the Design, Analysis, Modelling, and Simulation of an Unmanned Aerial Vehicle

Vogeltanz

2015

Arch Computat Methods Eng

View full text Add to dashboard Cite

The objective of this paper is to analyze free software for the design, analysis, modelling, and simulation of an unmanned aerial vehicle (UAV). Free software is the best choice when the reduction of production costs is necessary; nevertheless, the quality of free software may vary. This paper probably does not include all of the free software, but tries to describe or mention at least the most interesting programs. The first part of this paper summarizes the essential knowledge about UAVs, including the fundamentals of flight mechanics and aerodynamics, and the structure of a UAV system. The second section generally explains the modelling and simulation of a UAV. In the main section, more than 50 free programs for the design, analysis, modelling, and simulation of a UAV are described. Although the selection of the free software has been focused on small subsonic UAVs, the software can also be used for other categories of aircraft in some cases; e.g. for MAVs and large gliders. The applications with an historical importance are also included. Finally, the results of the analysis are evaluated and discussed -a block diagram of the free software is presented, possible connections between the programs are outlined, and future improvements of the free software are suggested.

show abstract

The NASA tetrahedral unstructured software system (TetrUSS)

Cited by 158 publications

References 28 publications

F-16XL Hybrid Reynolds-Averaged Navier–Stokes/Large-Eddy Simulation on Unstructured Grids

F-16XL Hybrid Reynolds-Averaged Navier–Stokes/Large-Eddy Simulation on Unstructured Grids

Iteration schemes for rapid post‐stall aerodynamic prediction of wings using a decambering approach

A Survey of Free Software for the Design, Analysis, Modelling, and Simulation of an Unmanned Aerial Vehicle

Contact Info

Product

Resources

About