Comparison between Wall-modeled and Wall-resolved Large Eddy Simulations for the prediction of boundary-layer separation around the side mirror of a full-scale vehicle

Ambo, Kei; Yoshino, Takashi; Kawamura, Tetsuhiro; Teramura, Minoru; Philips, David A.; Brès, Guillaume A.; Bose, Sanjeeb

doi:10.2514/6.2017-1661

Cited by 7 publications

(4 citation statements)

References 8 publications

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“…The application of these methods is also becoming important for automotive applications. Ambo et al [19] compared wall-modeled and wall-resolved large eddy simulations for the prediction of boundary-layer separation around the side mirror of a full-scale vehicle and in the work of Aljure [20] numerical simulations on the flow over a realistic generic car geometry were carried out.…”

Section: Fukushima and Kawaimentioning

confidence: 99%

Large-Eddy Simulation with Modeled Wall Stress for Complex Aerodynamics and Stall Prediction

et al. 2021

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The aerodynamics of aircraft high-lift devices at near-stall conditions is particularly difficult to predict numerically. The computational requirements for accurate wall-resolved Large-Eddy Simulations are currently prohibitive, whilst RANS models are generally reliable only for low angles of attack with fully-attached boundary layers. Methods such as DES resolve unsteadiness of the outer boundary layer and can predict separation, but they rely upon a thick RANS layer and highly-stretched cells which damp the resolved turbulent fluctuations near the wall. An alternative approach, adopted here, is to extend the LES down to the wall, employing a relatively large near-wall normal grid spacing and avoiding grid stretching and high aspect ratios near the wall. A boundary condition then applies the correct wall shear stress as

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Section: Fukushima and Kawaimentioning

confidence: 99%

Large-Eddy Simulation with Modeled Wall Stress for Complex Aerodynamics and Stall Prediction

et al. 2021

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“…Yuan et al 20 studied flow around mirror of Hartmann et al 11 and analyzed the influence of installation environment on turbulence in separation zone, demonstrating the role of the A-pillar vortex. Ambo et al 19 focused on application of a high fidelity LES method to the numerical prediction of the boundary layer separation on a convex surface of the mirror at a super-critical Reynolds number. Chu et al 21 used a simplified method of estimating the broadband noise sources, based on the steady-state RANS simulation, to optimize the shape of their mirror.…”

Section: Introductionmentioning

confidence: 99%

“…Real and simplified geometries of a side mirror were measured, for example, by Hartmann et al, 11 Werner et al, 12 and Siegert et al 13 Numerical simulations of these and other mirrors were done by Hartmann et al, 11 Frank and Munz, 14 Siegert et al, 13 and others. [15][16][17][18][19][20][21][22][23][24] In most of these works, authors applied hybrid approaches to aeroacoustics simulation. An exception is a paper by Frank and Munz, 14 who directly computed the tonal whistling noise for a very special simplified mirror geometry, which was designed and experimentally studied by Werner et al 12 The tonal noise in that flow was generated by a significant feedback of acoustics on a flow over a mirror with the non-optimized sharp edges.…”

Section: Introductionmentioning

confidence: 99%

“…Obviously, the standard hybrid approach with its one-way coupling of flow and acoustics is not applicable to analyze this phenomenon, which explains the application of the direct noise simulation using the compressible flow equations. Papers by Hartmann et al, 11 Yuan et al, 20 Ambo et al, 19 and Chu et al 21 reported on numerical investigations of real mirror geometries by different car manufacturers, installed either on the real full-scale cars or on simplified bodies. Hartmann et al 11 compared different flow simulation methods (finite-volume method vs. Lattice Boltzmann method).…”

Section: Introductionmentioning

confidence: 99%

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Application of LES combined with a wave equation for the simulation of noise induced by a flow past a generic side mirror

Guseva

Egorov

2022

International Journal of Aeroacoustics

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The paper presents validation results of a hybrid simulation method for aeroacoustics in turbulent flows at low Mach numbers. The hybrid method implemented in the Ansys Fluent® CFD package applies a scale-resolving turbulence model to compute the noise sources in an incompressible flow, while the noise propagation is modeled by a wave equation formulated for the acoustic potential. The selected test case deals with a flow and a sound field around a generic side view mirror of a car. The SBES model by Menter, which belongs to the class of the RANS-LES models, is used for the flow simulation. It switches to the Large Eddy Simulation (LES) mode in separated mixing layers and recirculation zone behind the mirror as well as in the following wake, where flow develops intensive turbulence and dominating noise sources. The acoustics wave equation is formulated in the model form of Kaltenbacher et al. and is applied in the time domain. The overall calculation is performed as a transient co-simulation on the same mesh using the finite-volume discretization method for both the flow and the acoustics parts. The wave equation is advanced in time using the HHT-α method. Obtained distribution of the mean wall pressure over the mirror surface closely matches the experimental one. Rich content of the resolved turbulent vortices in the separation zone and good agreement of the calculated and measured wall pressure spectra at sensor locations downstream the mirror evidence a proper LES resolution quality of noise sources. Comparison of the computed noise spectra at the remote microphones with the experimental data demonstrates the sound propagation accuracy and validates the overall aeroacoustics simulation method.

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Hybrid RANS/LES of an Adverse Pressure Gradient Turbulent Boundary Layer Using an Elliptic Blending Reynolds Stress Model and Anisotropic Linear Forcing

Erbig

Lardeau

2019

Progress in Hybrid RANS-LES Modelling

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Comparison between Wall-modeled and Wall-resolved Large Eddy Simulations for the prediction of boundary-layer separation around the side mirror of a full-scale vehicle

Cited by 7 publications

References 8 publications

Large-Eddy Simulation with Modeled Wall Stress for Complex Aerodynamics and Stall Prediction

Large-Eddy Simulation with Modeled Wall Stress for Complex Aerodynamics and Stall Prediction

Application of LES combined with a wave equation for the simulation of noise induced by a flow past a generic side mirror

Hybrid RANS/LES of an Adverse Pressure Gradient Turbulent Boundary Layer Using an Elliptic Blending Reynolds Stress Model and Anisotropic Linear Forcing

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