Numerical simulation (DNS and LES) of manipulated turbulent boundary layer flow over a surface-mounted fence

Orellano, Alexander; Wengle, Hans

doi:10.1016/s0997-7546(00)00115-1

Cited by 47 publications

(71 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Other values include Bergeles and Athanassiadis [3] (x R /h = 11), Durst and Rastogi [4] (x R /h = 16), all of which are under a turbulent condition with high free-stream turbulence. Similar scatter was reported for the fence geometry including Tropea and Gackstatter [2] (x R /h = 17), the DNS study of Orellano and Wengle [9] (x R /h = 13.2) and the experiment of Larsen [10] (x R /h = 11.7). Overall, the LES simulation has predicted the line mean position of the reattachment well.…”

Section: Mean Flow Fieldsupporting

confidence: 77%

“…This is comparable to the mean reattachment length for the current simulation. [2] (available only at 3 locations), Larsen [10] and the DNS data of Orellano and Wengle [9]. The results show good agreement with the data of Larsen [10] and the DNS data of Orellano and Wengle [9].…”

Section: Mean Flow Fieldsupporting

confidence: 75%

“…[2] (available only at 3 locations), Larsen [10] and the DNS data of Orellano and Wengle [9]. The results show good agreement with the data of Larsen [10] and the DNS data of Orellano and Wengle [9]. The freestream velocities of the data from Tropea and Gackstatter [2] are bigger than those predicted by the LES and the other two results, and peak at lower y-values.…”

Section: Mean Flow Fieldsupporting

confidence: 70%

“…The agreement between the LES results and the data of Larsen [10] and the DNS data of Orellano and Wengle [9] is encouraging. No measured data were presented by Tropea and Gackstatter [2].…”

Section: Mean Flow Fieldsupporting

confidence: 69%

“…The freestream velocities of the data from Tropea and Gackstatter [2] are bigger than those predicted by the LES and the other two results, and peak at lower y-values. This is attributed to the difference in blockage ratio used by Tropea and Gackstatter [2] which is very low (= 2), 5 in the case of Orellano and Wengle [9] and 8 for the current LES.…”

Section: Mean Flow Fieldmentioning

confidence: 88%

See 4 more Smart Citations

Spectral analysis of a transitional separated-reattached flow using Fourier and wavelet transforms

Abdalla¹,

Cook²

2007

WIT Transactions on Modelling and Simulation, Vol 46

View full text Add to dashboard Cite

Large-eddy simulations (LES) of transitional separating-reattaching flow over a square surface mounted obstacle (SSMO) and a forward-facing step (FFS) have been performed. The Reynolds number based on the uniform inlet velocity and the obstacle height is 4.5 × 10 3 . A dynamic subgrid-scale model is employed in this work. The mean LES results compare favourably with the available experimental and DNS data. This paper addresses the characteristic shedding modes associated with the separated-reattached flows on the SSMO and the FFS and sheds light on the use of the wavelet transform (WT) in extracting the content of a time history of a (velocity and/or pressure) signal compared to the traditional Fourier transform (FT). The turbulence spectra for the geometries revealed amplified frequency modes both upstream and downstream of the separation edge with those associated with the SSMO showing more clearly compared to the FFS. A frequency peak was detected at a location upstream of the separation line and immediately above the SSMO. The value of this frequency suggests that the upstream separated region is unstable via the Kelvin-Helmholtz instability and the peak can not be attributed to the flapping of the separated shear layer which is a phenomenon commonly associated with this class of flows. The WT captured events that are characterised by narrow periods (scales) and which happened over shorter times. Such events are smoothed out by the Fourier transform indicating the superiority of the WT over the FT.

show abstract

Section: Mean Flow Fieldsupporting

confidence: 77%

Section: Mean Flow Fieldsupporting

confidence: 75%

Section: Mean Flow Fieldsupporting

confidence: 70%

Section: Mean Flow Fieldsupporting

confidence: 69%

Section: Mean Flow Fieldmentioning

confidence: 88%

See 3 more Smart Citations

Spectral analysis of a transitional separated-reattached flow using Fourier and wavelet transforms

Abdalla¹,

Cook²

2007

WIT Transactions on Modelling and Simulation, Vol 46

View full text Add to dashboard Cite

show abstract

Numerical study of transitional separated–reattached flow over surface‐mounted obstacles using large‐eddy simulation

Abdalla

Cook

Yang

2006

Numerical Methods in Fluids

View full text Add to dashboard Cite

SUMMARYLarge-eddy simulation (LES) of transitional separating-reattaching flow on a square surface mounted obstacle has been performed. The Reynolds number based on the uniform inlet velocity and the obstacle height is 4.5 × 10 3 . A dynamic subgrid-scale model is employed in this work. The mean LES results compare favourably with the available experimental and direct numerical simulation (DNS) data. Extensive analysis of the time series signals of the velocity and pressure fields at different locations including positions close to solid surfaces, at the centre and edge of the separated-reattached boundary layer using the windowed Fourier transform (WFT) and the wavelet transform was performed. The spectra analysis revealed the nature of the amplified frequencies at all the important locations of the flow field. Excited modes that could be due to the movement (shedding) of large-scale structures and pairing of such types of structures are identified. A clear frequency peak was captured just upstream of the separation line. The value of the frequency peak and the low percentage of the back flow velocity compared to the freestream velocity in the current case strongly support the idea that this amplified frequency is most likely due to the Kelvin-Helmholtz (K-H) instability mechanism of the shear layer forming in the boundary of the small upstream separated region rather than being attributed to the flapping of the shear layer.

show abstract

An Embedded Flow Simulation Methodology for Flow over Fence Simulations

Anupindi

Sandberg

2017

Direct and Large-Eddy Simulation X

View full text Add to dashboard Cite

Numerical simulation (DNS and LES) of manipulated turbulent boundary layer flow over a surface-mounted fence

Cited by 47 publications

References 0 publications

Spectral analysis of a transitional separated-reattached flow using Fourier and wavelet transforms

Spectral analysis of a transitional separated-reattached flow using Fourier and wavelet transforms

Numerical study of transitional separated–reattached flow over surface‐mounted obstacles using large‐eddy simulation

An Embedded Flow Simulation Methodology for Flow over Fence Simulations

Contact Info

Product

Resources

About