An experimental search for near-wall boundary conditions for large eddy simulation

We studied the effect of wall boundary conditions on the statistics in a wall-modeled large-eddy simulation (WMLES) of turbulent channel flows. Three different forms of the boundary condition based on the mean stress-balance equations were used to supply the correct mean wall shear stress for a wide range of Reynolds numbers and grid resolutions applicable to WMLES. In addition to the widely used Neumann boundary condition at the wall, we considered a case with a no-slip condition at the wall in which the wall stress was imposed by adjusting the value of the eddy viscosity at the wall. The results showed that the type of boundary condition utilized had an impact on the statistics (e.g., mean velocity profile and turbulence intensities) in the vicinity of the wall, especially at the first off-wall grid point. Augmenting the eddy viscosity at the wall resulted in improved predictions of statistics in the near-wall region, which should allow the use of information from the first off-wall grid point for wall models without additional spatial or temporal filtering. This boundary condition is easy to implement and provides a simple solution to the well-known log-layer mismatch in WMLES.

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Constrained Large-Eddy Simulation of Compressible Flow Past a Circular Cylinder

Communications in Computational Physics ◽

10.4208/cicp.050513.270513a ◽

2014 ◽

Vol 15 (2) ◽

pp. 388-421 ◽

Cited By ~ 11

Author(s):

Renkai Hong ◽

Zhenhua Xia ◽

Yipeng Shi ◽

Zuoli Xiao ◽

Shiyi Chen

Keyword(s):

Mach Number ◽

Large Eddy Simulation ◽

Boundary Conditions ◽

Skin Friction ◽

Stagnation Point ◽

Eddy Simulation ◽

Wall Boundary ◽

Wall Boundary Conditions ◽

Large Eddy ◽

Rear Stagnation Point

AbstractCompressible flow past a circular cylinder at an inflow Reynolds number of 2x105is numerically investigated by using a constrained large-eddy simulation (CLES) technique. Numerical simulation with adiabatic wall boundary condition and at a free-stream Mach number of 0.75 is conducted to validate and verify the performance of the present CLES method in predicting separated flows. Some typical and characteristic physical quantities, such as the drag coefficient, the root-mean-square lift fluctuations, the Strouhal number, the pressure and skin friction distributions around the cylinder,etc.are calculated and compared with previously reported experimental data, finer-grid large-eddy simulation (LES) data and those obtained in the present LES and detached-eddy simulation (DES) on coarse grids. It turns out that CLES is superior to DES in predicting such separated flow and that CLES can mimic the intricate shock wave dynamics quite well. Then, the effects of Mach number on the flow patterns and parameters such as the pressure, skin friction and drag coefficients, and the cylinder surface temperature are studied, with Mach number varying from 0.1 to 0.95. Non-monotonic behaviors of the pressure and skin friction distributions are observed with increasing Mach number and the minimum mean separation angle occurs at a subcritical Mach number of between 0.3 and 0.5. Additionally, the wall temperature effects on the thermodynamic and aerodynamic quantities are explored in a series of simulations using isothermal wall boundary conditions at three different wall temperatures. It is found that the flow separates earlier from the cylinder surface with a longer recirculation length in the wake and a higher pressure coefficient at the rear stagnation point for higher wall temperature. Moreover, the influences of different thermal wall boundary conditions on the flow field are gradually magnified from the front stagnation point to the rear stagnation point. Moreover, the influences of different thermal wall boundary conditions on the flow field are graduallymagnified from the front stagnation point to the rear stagnation point. It is inferred that the CLES approach in its current version is a useful and effective tool for simulating wall-bounded compressible turbulent flows with massive separations.

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Modeling of Effect of Inflow Turbulence Data on Large Eddy Simulation of Circular Cylinder Flows

Journal of Fluids Engineering ◽

10.1115/1.2734225 ◽

2006 ◽

Vol 129 (6) ◽

pp. 780-790 ◽

Cited By ~ 4

Author(s):

M. Tutar ◽

I. Celik ◽

I. Yavuz

Keyword(s):

Reynolds Number ◽

Circular Cylinder ◽

Large Eddy Simulation ◽

Boundary Conditions ◽

Wake Flow ◽

Eddy Simulation ◽

Turbulent Inflow ◽

Large Eddy ◽

Inflow Turbulence ◽

Near Wall

A random flow generation (RFG) algorithm for a previously established large eddy simulation (LES) code is successfully incorporated into a finite element fluid flow solver to generate the required inflow/initial turbulence boundary conditions for the three-dimensional (3D) LES computations of viscous incompressible turbulent flow over a nominally two-dimensional (2D) circular cylinder at Reynolds number of 140,000. The effect of generated turbulent inflow boundary conditions on the near wake flow and the shear layer and on the prediction of integral flow parameters is studied based on long time average results. Because the near-wall region cannot be resolved for high Reynolds number flows, no-slip velocity boundary function is used, but wall effects are taken into consideration with a near-wall modeling methodology that comprises the no-slip function with a modified form of van Driest damping approach to reduce the subgrid length scale in the vicinity of the cylinder wall. Simulations are performed for a 2D and a 3D configuration, and the simulation results are compared to each other and to the experimental data for different turbulent inflow boundary conditions with varying degree of inflow turbulence to assess the functionality of the RFG algorithm for the present LES code and, hence, its influence on the vortex shedding mechanism and the resulting flow field predictions.

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Large-eddy simulation with near-wall modeling using weakly enforced no-slip boundary conditions

Computers & Fluids ◽

10.1016/j.compfluid.2015.06.016 ◽

2015 ◽

Vol 118 ◽

pp. 172-181 ◽

Cited By ~ 18

Author(s):

Roozbeh Golshan ◽

Andrés E. Tejada-Martínez ◽

Mario Juha ◽

Yuri Bazilevs

Keyword(s):

Large Eddy Simulation ◽

Boundary Conditions ◽

Slip Boundary Conditions ◽

Slip Boundary ◽

Eddy Simulation ◽

Large Eddy ◽

Near Wall

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LAGRANGIAN VORTEX METHOD WITH IMPROVED BOUNDARY CONDITIONS TO STUDY THE AERODYNAMICS OF BLUFF BODY CLOSE TO A MOVING GROUND USING LAGRANGIAN LARGE EDDY SIMULATION

10.26678/abcm.encit2018.cit18-0688 ◽

2018 ◽

Author(s):

Crystianne Lilian Andrade ◽

Alex Bimbato ◽

Luiz Antonio Alcântara Pereira

Keyword(s):

Large Eddy Simulation ◽

Boundary Conditions ◽

Bluff Body ◽

Vortex Method ◽

Eddy Simulation ◽

Large Eddy

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Investigation of the Turbulent Near Wall Flame Behavior for a Sidewall Quenching Burner by Means of a Large Eddy Simulation and Tabulated Chemistry

Fluids ◽

10.3390/fluids3030065 ◽

2018 ◽

Vol 3 (3) ◽

pp. 65 ◽

Cited By ~ 1

Author(s):

Arne Heinrich ◽

Guido Kuenne ◽

Sebastian Ganter ◽

Christian Hasse ◽

Johannes Janicka

Keyword(s):

Heat Flux ◽

Large Eddy Simulation ◽

Gas Turbines ◽

Internal Combustion Engines ◽

Heat Fluxes ◽

Maximum Heat ◽

Eddy Simulation ◽

Tabulated Chemistry ◽

Large Eddy ◽

Near Wall

Combustion will play a major part in fulfilling the world’s energy demand in the next 20 years. Therefore, it is necessary to understand the fundamentals of the flame–wall interaction (FWI), which takes place in internal combustion engines or gas turbines. The FWI can increase heat losses, increase pollutant formations and lowers efficiencies. In this work, a Large Eddy Simulation combined with a tabulated chemistry approach is used to investigate the transient near wall behavior of a turbulent premixed stoichiometric methane flame. This sidewall quenching configuration is based on an experimental burner with non-homogeneous turbulence and an actively cooled wall. The burner was used in a previous study for validation purposes. The transient behavior of the movement of the flame tip is analyzed by categorizing it into three different scenarios: an upstream, a downstream and a jump-like upstream movement. The distributions of the wall heat flux, the quenching distance or the detachment of the maximum heat flux and the quenching point are strongly dependent on this movement. The highest heat fluxes appear mostly at the jump-like movement because the flame behaves locally like a head-on quenching flame.

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A Method of Measuring Turbulent Flow Structures With Particle Image Velocimetry and Incorporating Into Boundary Conditions of Large Eddy Simulations

Journal of Fluids Engineering ◽

10.1115/1.4039256 ◽

2018 ◽

Vol 140 (7) ◽

Cited By ~ 4

Author(s):

Puxuan Li ◽

Steve J. Eckels ◽

Garrett W. Mann ◽

Ning Zhang

Keyword(s):

Particle Image Velocimetry ◽

Large Eddy Simulation ◽

Boundary Conditions ◽

Particle Image ◽

Advantages And Disadvantages ◽

Eddy Simulation ◽

Piv Measurement ◽

Image Velocimetry ◽

Large Eddy ◽

Inlet Conditions

The setup of inlet conditions for a large eddy simulation (LES) is a complex and important problem. Normally, there are two methods to generate the inlet conditions for LES, i.e., synthesized turbulence methods and precursor simulation methods. This study presents a new method for determining inlet boundary conditions of LES using particle image velocimetry (PIV). LES shows sensitivity to inlet boundary conditions in the developing region, and this effect can even extend into the fully developed region of the flow. Two kinds of boundary conditions generated from PIV data, i.e., steady spatial distributed inlet (SSDI) and unsteady spatial distributed inlet (USDI), are studied. PIV provides valuable field measurement, but special care is needed to estimate turbulent kinetic energy and turbulent dissipation rate for SSDI. Correlation coefficients are used to analyze the autocorrelation of the PIV data. Different boundary conditions have different influences on LES, and their advantages and disadvantages for turbulence prediction and static pressure prediction are discussed in the paper. Two kinds of LES with different subgrid turbulence models are evaluated: namely dynamic Smagorinsky–Lilly model (Lilly model) and wall modeled large eddy simulation (WMLES model). The performances of these models for flow prediction in a square duct are presented. Furthermore, the LES results are compared with PIV measurement results and Reynolds-stress model (RSM) results at a downstream location for validation.

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