Multigrid solution of the Euler equations for aircraft configurations

Jameson, A.; Baker, Timothy J.

doi:10.2514/6.1984-93

Cited by 156 publications

(42 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The density and pressure on the wall boundary are obtained by extrapolation from the interior solution. On the far-field boundary, the treatment of boundary condition is based on the Riemann invariants for a one-dimensional flow normal to the boundary [34]. For the DU97-Flatback-FCC and DU97-Flatback-PCC airfoils with the Coanda jet activated, the high-pressure cavity is included in simulations.…”

Section: Boundary Conditionsmentioning

confidence: 99%

Flow Control over the Blunt Trailing Edge of Wind Turbine Airfoils Using Circulation Control

Dong

Qiao

et al. 2018

Energies

View full text Add to dashboard Cite

Abstract:A new partial circulation control (PCC) method is implemented on the blunt trailing edge DU97-Flatback airfoil, and compared with the traditional full circulation control (FCC) based on numerical analysis. When the Coanda jet is deactivated, PCC has an attractive advantage over FCC, since the design of PCC doesn't degrade aerodynamic characteristics of the baseline flatback section, in contrast to FCC, which is important in practical use in case of failure of the circulation control system. When the Coanda jet is activated, PCC also outperforms FCC in several respects. PCC can produce much higher lift coefficients than FCC over the entire range of angles of attack as well as the entire range of jet momentum coefficients under investigation, but with slightly higher drag coefficients. The flow field of PCC is less complex than that of FCC, indicating less energy dissipation in the main flow and hence less power expenditure for the Coanda jet. The aerodynamic figure of merit (AFM) and control efficiency for circulation control are defined, and results show that PCC has much higher AFM and control efficiency than FCC. It is demonstrated that PCC outperforms FCC in terms of effectiveness, efficiency and reliability for flow control in the blunt trailing edge wind turbine application.

show abstract

Section: Boundary Conditionsmentioning

confidence: 99%

Flow Control over the Blunt Trailing Edge of Wind Turbine Airfoils Using Circulation Control

Dong

Qiao

et al. 2018

Energies

View full text Add to dashboard Cite

show abstract

“…This tool couples the multiblock Euler and Navier Stokes flow solver FLO107-MB 16 to an H-mesh generator adapted from the HFLO4 code of Jameson and Baker, 17 and to the PC Boom software for far field propagation developed by Wyle Associates. The H-type mesh, which is generated automatically from the geometric definition, can handle arbitrary wing-fuselage-canard configurations.…”

Section: Nonlinear Integrated Boom Analysis Environmentmentioning

confidence: 99%

Advanced algorithms for design and optimization of Quiet Supersonic Platforms

Alonso

Jameson²,

Kroo³

2002

40th AIAA Aerospace Sciences Meeting &Amp; Exhibit

Self Cite

View full text Add to dashboard Cite

This paper describes the work carried out within the Stanford University group as part of the DARPA-funded Quiet Supersonic Platform (QSP) project. The objective of our work was to develop advanced numerical methods to facilitate the analysis and design of low sonic boom aircraft. The focus of the boom reduction activities was placed on two main ideas: the shaping of the configuration and a multidisciplinary design approach to minimize its total empty weight. Accurate and efficient tools are needed to achieve these tasks. Our approach was meant to enhance the existing state-of-the-art which was developed in the 1970s and during the early stages of the High Speed Research (HSR) program. For that purpose, we designed tools that would ultimately become fully nonlinear (in contrast with current design efforts based on linear theories of the 1970s). These tools are also able to account for important tradeoffs between boom reduction and aerodynamic perormance, as well as other disciplines. Because of the difficulty of the problem, the tools were designed to support a combination of gradient and non-gradient automatic optimization techniques. As a result of our efforts, rapid turnaround boom analysis and design methods were developed. These methods permit the investigation of radical configuration changes and their effect on the ground boom signature and the L/D ratio of the aircraft. We have also created an environment for the automatic nonlinear analysis of QSP configurations based on the multiblock flow solver FLO107-MB. In addition, we have extended the adjoint-based design method to treat remote sensitivities to near-field pressure signatures, allowing for a very large number of parameters to be used in modifications of the aircraft geometry. All tools were carefully validated against existing experimental data, other boom prediction programs, and with systematic mesh refinement studies.

show abstract

“…Multistage time-stepping schemes with central differencing and multigrid acceleration [1,2,3] were demonstrated to be quite effective in computing subsonic and transonic flows 'ver aerodynamic components and configurations. With the recent resurgence of interest in high-speed flight vehicles, we now need to construct versatile algorithms for hypersonic flow.…”

Section: Introductionmentioning

confidence: 99%

An effective multigrid method for high‐speed flows

Swanson

Turkel

White

1992

Commun. appl. numer. methods

View full text Add to dashboard Cite

We consider the use of a multigrid method with central differencing to solve the Navier-Stokes equations for high-speed flows. The time-dependent form of the equations is integrated with a Runge-Kutta scheme accelerated by local time stepping and variable coefficient implicit residual smoothing. Of particular importance are the details of the numerical dissipation formulation, especially the switch between the second and fourth difference terms. Solutions are given for two-dimensional lamipar flow over a circular cylinder and a 15 degree compression ramp. iI IntroductionDuring the 1980's a wide variety of numerical schemes were investigated for solving the Euler and Navier-Stokes equations. Multistage time-stepping schemes with central differencing and multigrid acceleration [1,2,3] were demonstrated to be quite effective in computing subsonic and transonic flows 'ver aerodynamic components and configurations. With the recent resurgence of interest in high-speed flight vehicles, we now need to construct versatile algorithms for hypersonic flow. One must keep in mind that hypersonic flows represent a formidable challenge for any flow solver. I1 particular, strong shock and expansion waves can occur in the flow field, and the3 can interact with each other and with shear layers (i.e., boundary layers, jets, wakes). Such strong nonlinear behavior and interactions can easily cause divergence of any numerical integration procedure. This is especially true during the initial phase of a calculation with a time-dependent method. So even the most successful algorithms of the last decade may require significant modifications to be effective for hypersonic flows.An initial effort [4] to apply a central-difference multigrid algorithm to high-speed flows resulted in numerical difficulties that prevented the calculation of two-dimensional flows (i.e., blunt body and wedge type) with a Mach number higher than about 7. In order to compute such flows a low Courant-Friedrichs-Lewy (CFL) number was required. Thus four and five stage schemes were not practical, since there is substantial deterioration in the high frequency damping of the scheme due to the large reduction in the CFL number. The CFL restriction reduced the potential of the scheme as a viscous flow solver. More recently an algorithm utilizing a semicoarsening technique, a symmetric TVD formulation, and a three stage Runge-Kutta scheme [5] was proposed and used to compute high Reynolds number (laminar) Mach 10 flow over an airfoil at 10 degrees angle of attack. A good resolution of the bow shock wave and a reasonable convergence rate were obtained. The method of semicoarsening considered required a much more complicated cycle strategy than that employed with standard multigrid methods. In addition, it appears to be somewhat cumbersome to implement in three dimensions.It is our contention that standard multigrid techniques can be u:.,d in conjunction with central differencing to compute hypersonic flows effectively. To achieve such success with these techniques ...

show abstract

Multigrid solution of the Euler equations for aircraft configurations

Cited by 156 publications

References 5 publications

Flow Control over the Blunt Trailing Edge of Wind Turbine Airfoils Using Circulation Control

Flow Control over the Blunt Trailing Edge of Wind Turbine Airfoils Using Circulation Control

Advanced algorithms for design and optimization of Quiet Supersonic Platforms

An effective multigrid method for high‐speed flows

Contact Info

Product

Resources

About