scholarly journals A generally applicable hybrid unsteady Reynolds-averaged Navier–Stokes closure scaled by turbulent structures

2021 ◽  
Vol 33 (10) ◽  
pp. 105117
Author(s):  
Giancarlo Lenci ◽  
Jinyong Feng ◽  
Emilio Baglietto
Keyword(s):  
Navier Stokes ◽  
Turbulent Structures ◽  
Reynolds Averaged Navier Stokes

Reynolds-averaged Navier–Stokes simulation of hydrofoil effects on hydrodynamic coefficients of a catamaran in forced oscillation

2016 ◽  
Vol 231 (2) ◽  
pp. 364-383
Author(s):  
Amin Najafi ◽  
Mohammad Saeed Seif
Keyword(s):  
High Speed ◽  
Experimental Approach ◽  
Navier Stokes ◽  
Hydrodynamic Coefficients ◽  
Laboratory Equipment ◽  
Factors Affecting ◽  
High Frequencies ◽  
Frequency Independent ◽  
Reynolds Averaged Navier Stokes

Determination of high-speed crafts’ hydrodynamic coefficients will help to analyze the dynamics of these kinds of vessels and the factors affecting their dynamic stabilities. Also, it can be useful and effective in controlling the vessel instabilities. The main purpose of this study is to determine the coefficients of longitudinal motions of a planing catamaran with and without a hydrofoil using Reynolds-averaged Navier–Stokes method to evaluate the foil effects on them. Determination of hydrodynamic coefficients by experimental approach is costly and requires meticulous laboratory equipment; therefore, utilizing the numerical methods and developing a virtual laboratory seem highly efficient. In this study, the numerical results for hydrodynamic coefficients of a high-speed craft are verified against Troesch’s experimental results. In the following, after determination of hydrodynamic coefficients of a planing catamaran with and without foil, the foil effects on its hydrodynamic coefficients are evaluated. The results indicate that most of the coefficients are frequency-independent especially at high frequencies.

Hybrid LES Approach for Practical Turbomachinery Flows—Part I: Hierarchy and Example Simulations

2011 ◽  
Vol 134 (2) ◽  
Author(s):  
Paul Tucker ◽  
Simon Eastwood ◽  
Christian Klostermeier ◽  
Richard Jefferson-Loveday ◽  
James Tyacke ◽  
...  
Keyword(s):  
Convex Surface ◽  
Computational Cost ◽  
Companion Paper ◽  
Navier Stokes ◽  
Computationally Efficient ◽  
Turbulent Structures ◽  
Hybrid Strategy ◽  
Eddy Simulation ◽  
Related Approach ◽  
Les Model

Unlike Reynolds-averaged Navier–Stokes (RANS) models that need calibration for different flow classes, LES (where larger turbulent structures are resolved by the grid and smaller modeled in a fashion reminiscent of RANS) offers the opportunity to resolve geometry dependent turbulence as found in complex internal flows—albeit at substantially higher computational cost. Based on the results for a broad range of studies involving different numerical schemes, large eddy simulation (LES) models and grid topologies, an LES hierarchy and hybrid LES related approach is proposed. With the latter, away from walls, no LES model is used, giving what can be termed numerical LES (NLES). This is relatively computationally efficient and makes use of the dissipation present in practical industrial computational fluid dynamics (CFD) programs. Near walls, RANS modeling is used to cover over numerous small structures, the LES resolution of which is generally intractable with current computational power. The linking of the RANS and NLES zones through a Hamilton–Jacobi equation is advocated. The RANS-NLES hybridization makes further sense for compressible flow solvers, where, as the Mach number tends to zero at walls, excessive dissipation can occur. The hybrid strategy is used to predict flow over a rib roughened surface and a jet impinging on a convex surface. These cases are important for blade cooling and show encouraging results. Further results are presented in a companion paper.

scholarly journals Identification of severe wind conditions using a Reynolds Averaged Navier-Stokes solver

2007 ◽  
Vol 75 ◽  
pp. 012053 ◽  
Author(s):  
N N Sørensen ◽  
A Bechmann ◽  
J Johansen ◽  
L Myllerup ◽  
P Botha ◽  
...  
Keyword(s):  
Navier Stokes ◽  
Reynolds Averaged Navier Stokes

Linear Stability-Based Smooth Reynolds-Averaged Navier–Stokes Transition Model for Aerodynamic Flows

AIAA Journal ◽  
2021 ◽  
pp. 1-14
Author(s):  
Gustavo Luiz Olichevis Halila ◽  
Anil Yildirim ◽  
Charles A. Mader ◽  
Krzysztof J. Fidkowski ◽  
Joaquim R. R. A. Martins
Keyword(s):  
Linear Stability ◽  
Navier Stokes ◽  
Transition Model ◽  
Aerodynamic Flows ◽  
Reynolds Averaged Navier Stokes

Hybrid Large Eddy Simulation/Reynolds-Averaged Navier–Stokes Analysis of a Premixed Ethylene-Fueled Dual-Mode Scramjet Combustor

AIAA Journal ◽  
2021 ◽  
pp. 1-17
Author(s):  
Tanner B. Nielsen ◽  
Jack R. Edwards ◽  
Harsha K. Chelliah ◽  
Damien Lieber ◽  
Clayton Geipel ◽  
...  
Keyword(s):  
Large Eddy Simulation ◽  
Navier Stokes ◽  
Dual Mode ◽  
Eddy Simulation ◽  
Scramjet Combustor ◽  
Large Eddy ◽  
Reynolds Averaged Navier Stokes

Output-Based Adaptive Reynolds-Averaged Navier–Stokes Higher-Order Finite Element Solutions on a Multielement Airfoil

AIAA Journal ◽  
2021 ◽  
pp. 1-14
Author(s):  
Carmen-Ioana Ursachi ◽  
Marshall C. Galbraith ◽  
Steven R. Allmaras ◽  
David L. Darmofal
Keyword(s):  
Finite Element ◽  
Higher Order ◽  
Navier Stokes ◽  
Reynolds Averaged Navier Stokes
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