A structural subgrid-scale model for relative dispersion in large-eddy simulation of isotropic turbulent flows by coupling kinematic simulation with approximate deconvolution method

2018 ◽  
Vol 30 (10) ◽  
pp. 105110 ◽  
Keyword(s):  
Turbulent Flows ◽  
Relative Dispersion ◽  
Scale Model ◽  
Subgrid Scale ◽  
Deconvolution Method ◽  
Kinematic Simulation ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Subgrid Scale Model ◽  
Approximate Deconvolution

Large-Eddy Simulation of Flow in a Low-Pressure Turbine Cascade

2012 ◽  
Author(s):  
Gorazd Medic ◽  
Om Sharma
Keyword(s):  
Reynolds Number ◽  
Turbulence Intensity ◽  
Free Stream ◽  
Reynolds Numbers ◽  
Scale Model ◽  
Subgrid Scale ◽  
Low Pressure Turbine ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Subgrid Scale Model

Flow over three low-pressure turbine airfoils presented in [1] is analyzed for a range of Reynolds numbers (30,000 to 150,000) by means of large-eddy simulation. Baseline computational grid for these 2D linear cascade configurations consisted of 35 millions cells, and additional finer grids of 70 millions cells were used for grid sensitivity studies. For these low Reynolds number flows, this represents a quasi-DNS resolution which minimizes the role of the subgrid-scale model — however, WALE subgrid-scale model [7] was still employed. The configurations were analyzed for low free-stream turbulence intensity, as well as for 4% turbulence intensity at free-stream. Laminar separation exists on the suction side, and, depending on the Reynolds number, the flow at the outer edge of the separation either transitions, and the separation closes before the trailing edge, or not. Detailed comparisons to measurements are presented for computed surface pressure and total pressure losses over the range of Reynolds numbers for all three airfoils; these show that LES analyses are able to capture the main trends across all three geometries.

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