LES Validation for a Rotating Cylindrical Cavity With Radial Inflow

2016 ◽  
Author(s):  
Michel Onori ◽  
Dario Amirante ◽  
Nicholas J. Hills ◽  
John W. Chew
Keyword(s):  
Boundary Layers ◽  
Source Region ◽  
Tangential Velocity ◽  
Large Eddy Simulations ◽  
Navier Stokes ◽  
Subgrid Scale ◽  
Rotating Cavity ◽  
Scale Models ◽  
Large Eddy ◽  
Type Boundary

This paper describes Large-Eddy Simulations (LES) of the flow in a rotating cavity with narrow inter-disc spacing and a radial inflow introduced from the shroud. Simulations have been conducted using a compressible, unstructured, finite-volume solver, and testing different subgrid scale models. These include the standard Smagorinsky model with Van Driest damping function near the wall, the WALE model and the implicit LES procedure. Reynolds averaged Navier-Stokes (RANS) results, based on the Spalart-Allmaras and SST k-ω models, are also presented. LES solutions reveal a turbulent source region, a laminar oscillating core with almost zero axial and radial velocity and turbulent Ekman type boundary layers along the discs. Validations are carried out against the experimental data available from the study of Firouzian et al. [1]. It is shown that the tangential velocity and the pressure drop across the cavity are very well predicted by both RANS and LES, although significant differences are observed in the velocity profiles within the boundary layers.

Subgrid-scale models for large-eddy simulations of compressible wall bounded flows

AIAA Journal ◽  
2000 ◽  
Vol 38 ◽  
pp. 1340-1350 ◽  
Author(s):  
E. Lenormand ◽  
P. Sagaut ◽  
L. Ta Phuoc ◽  
P. Comte
Keyword(s):  
Large Eddy Simulations ◽  
Subgrid Scale ◽  
Scale Models ◽  
Large Eddy ◽  
Wall Bounded Flows

The effect of subgrid-scale models on the vortices computed from large-eddy simulations

2004 ◽  
Vol 16 (12) ◽  
pp. 4506-4534 ◽  
Author(s):  
Carlos B. da Silva ◽  
José C. F. Pereira
Keyword(s):  
Large Eddy Simulations ◽  
Subgrid Scale ◽  
Scale Models ◽  
Large Eddy

Subgrid-Scale Models for Large-Eddy Simulations of Compressible Wall Bounded Flows

AIAA Journal ◽  
2000 ◽  
Vol 38 (8) ◽  
pp. 1340-1350 ◽  
Author(s):  
E. Lenormand ◽  
P. Sagaut ◽  
L. Ta Phuoc ◽  
P. Comte
Keyword(s):  
Large Eddy Simulations ◽  
Subgrid Scale ◽  
Scale Models ◽  
Large Eddy ◽  
Wall Bounded Flows

scholarly journals LES and RANS Investigations Into Buoyancy-Affected Convection in a Rotating Cavity With a Central Axial Throughflow

2006 ◽  
Author(s):  
Zixiang Sun ◽  
Klas Lindblad ◽  
John W. Chew ◽  
Colin Young
Keyword(s):  
Heat Transfer ◽  
Tangential Velocity ◽  
Navier Stokes ◽  
Test Cases ◽  
Test Rig ◽  
Rotating Disc ◽  
Eddy Simulation ◽  
Rotating Cavity ◽  
Large Eddy ◽  
Les Model

The buoyancy-affected flow in rotating disc cavities, such as occurs in compressor disc stacks, is known to be complex and difficult to predict. In the present work large eddy simulation (LES) and unsteady Reynolds-averaged Navier-Stokes (RANS) solutions are compared with other workers’ measurements from an engine representative test rig. The Smagorinsky-Lilly model was employed in the LES simulations, and the RNG k-ε turbulence model was used in the RANS modelling. Three test cases were investigated in a range of Grashof number Gr = 1.87 to 7.41×108 and buoyancy number Bo = 1.65 to 11.5. Consistent with experimental observation, strong unsteadiness was clearly observed in the results of both models, however the LES results exhibited a finer flow structure than the RANS solution. The LES model also achieved significantly better agreement with velocity and heat transfer measurements than the RANS model. Also, temperature contours obtained from the LES results have a finer structure than the tangential velocity contours. Based on the results obtained in this work, further application of LES to flows of industrial complexity is recommended.

Effective Subgrid Modeling From the ILES Simulation of Compressible Turbulence

2007 ◽  
Vol 129 (12) ◽  
pp. 1493-1496 ◽  
Author(s):  
William J. Rider
Keyword(s):  
Incompressible Flows ◽  
Stokes Equations ◽  
Standard Form ◽  
Large Eddy Simulations ◽  
Compressible Turbulence ◽  
Navier Stokes ◽  
Subgrid Scale ◽  
Self Similarity ◽  
Large Eddy ◽  
Similarity Model

Implicit large eddy simulation (ILES) has provided many computer simulations with an efficient and effective model for turbulence. The capacity for ILES has been shown to arise from a broad class of numerical methods with specific properties producing nonoscillatory solutions using limiters that provide these methods with nonlinear stability. The use of modified equation has allowed us to understand the mechanisms behind the efficacy of ILES as a model. Much of the understanding of the ILES modeling has proceeded in the realm of incompressible flows. Here, we extend this analysis to compressible flows. While the general conclusions are consistent with our previous findings, the compressible case has several important distinctions. Like the incompressible analysis, the ILES of compressible flow is dominated by an effective self-similarity model (Bardina, J., Ferziger, J. H., and Reynolds, W. C., 1980, “Improved Subgrid Scale Models for Large Eddy Simulations,” AIAA Paper No. 80–1357; Borue, V., and Orszag, S. A., 1998, “Local Energy Flux and Subgrid-Scale Statistics in Three Dimensional Turbulence,” J. Fluid Mech., 366, pp. 1–31; Meneveau, C., and Katz, J., 2000, “Scale-Invariance and Turbulence Models for Large-Eddy Simulations,” Annu. Rev. Fluid. Mech., 32, pp. 1–32). Here, we focus on one of these issues, the form of the effective subgrid model for the conservation of mass equations. In the mass equation, the leading order model is a self-similarity model acting on the joint gradients of density and velocity. The dissipative ILES model results from the limiter and upwind differencing resulting in effects proportional to the acoustic modes in the flow as well as the convective effects. We examine the model in several limits including the incompressible limit. This equation differs from the standard form found in the classical Navier–Stokes equations, but generally follows the form suggested by Brenner (2005, “Navier-Stokes Revisited,” Physica A, 349(1–2), pp. 60–133) in a modification of Navier–Stokes necessary to successfully reproduce some experimentally measured phenomena. The implications of these developments are discussed in relation to the usual turbulence modeling approaches.

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