Large Eddy simulation with dynamic subgrid stress model of a rectangular impinging jet

2007 ◽  
pp. 382-387
Author(s):  
T. Cziesla ◽  
N. K. Mitra
Keyword(s):  
Large Eddy Simulation ◽  
Impinging Jet ◽  
Stress Model ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Subgrid Stress

scholarly journals A physical-space version of the stretched-vortex subgrid-stress model for large-eddy simulation

2000 ◽  
Vol 12 (7) ◽  
pp. 1810-1825 ◽  
Author(s):  
Tobias Voelkl ◽  
D. I. Pullin ◽  
Daniel C. Chan
Keyword(s):  
Large Eddy Simulation ◽  
Physical Space ◽  
Stress Model ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Subgrid Stress

scholarly journals A vortex-based subgrid stress model for large-eddy simulation

1997 ◽  
Vol 9 (8) ◽  
pp. 2443-2454 ◽  
Author(s):  
Ashish Misra ◽  
D. I. Pullin
Keyword(s):  
Large Eddy Simulation ◽  
Stress Model ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Subgrid Stress

Influences of the Height of Two Wall-Mounted Rectangle Cylinders on their Flow Patterns and Drag Coefficients

2011 ◽  
Vol 66-68 ◽  
pp. 1832-1837
Author(s):  
Hai Yuan Li ◽  
Da Wen Xue ◽  
Zhi Hua Chen ◽  
Bao Ming Li
Keyword(s):  
Large Eddy Simulation ◽  
Compressible Flow ◽  
Scale Effects ◽  
Stress Model ◽  
Subgrid Scale ◽  
Drag Coefficients ◽  
Eddy Simulation ◽  
Flow Past ◽  
Large Eddy ◽  
Subgrid Stress

Large eddy simulation has been applied to simulate the compressible flow past one and two wall-mounted rectangle cylinders, respectively. The dynamic subgrid stress model is employed to approximate the subgrid scale effects. Flow past one single wall-mounted cylinder is used as an example to validate our code. Flow past two wall-mounted cylinders is chosen for investigating the variation of flow fields and drag coefficients under different heights of two cylinders. Our numerical results show that, with certain ratio of two cylinder height, their drag coefficient can be improved, which is important for practical building industries.

A comparative turbulent flow study of unconfined orthogonal and oblique slot impinging jet using large-eddy simulation

2020 ◽  
Vol 32 (9) ◽  
pp. 095116
Author(s):  
Shashikant Pawar ◽  
Devendra Kumar Patel ◽  
Mukul Bisoi ◽  
Subhransu Roy
Keyword(s):  
Large Eddy Simulation ◽  
Turbulent Flow ◽  
Impinging Jet ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Flow Study

Analysis and Optimization of Turbulent Mixing With Large Eddy Simulation

2006 ◽  
Author(s):  
Ying Huai ◽  
Amsini Sadiki
Keyword(s):  
Large Eddy Simulation ◽  
Turbulent Mixing ◽  
Optimization Procedure ◽  
Impinging Jet ◽  
Computational Domain ◽  
Original Design ◽  
Mixing Processes ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Practical Engineering

In this work, Large Eddy Simulation (LES) has been carried out to analyze the turbulent mixing processes in an impinging jet configuration. To characterize and quantify turbulent mixing processes, in terms of scalar structures and degree of mixing, three parameters have been basically introduced. They are “mixedness parameter”, which represents the probability of mixed fluids in computational domain, the Spatial Mixing Deficiency (SMD) and the Temporal Mixing Deficiency (TMD) parameters for characterizing the mixing at different scalar scale degrees. With help of these parameters, a general mixing optimization procedure has then been suggested and achieved in an impinging jet configuration. An optimal jet angle was estimated and the overall mixing degree with this jet angle reached around six times more than the original design. It turns out that the proposed idea and methodology can be helpful for practical engineering design processes.

Gas Turbine Blade Cooling Passage With V and Broken V Shaped Ribs

2016 ◽  
Author(s):  
Sourabh Kumar ◽  
Ryoichi S. Amano
Keyword(s):  
Heat Transfer ◽  
Large Eddy Simulation ◽  
Gas Turbine ◽  
Heat Extraction ◽  
Design Stage ◽  
Stress Model ◽  
Cfd Simulations ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Cooling Passage

Gas turbine plays a significant role throughout the industrial world. Aircraft propulsion, land-based power generation, and marine propulsion are most notable sectors where gas turbines are extensively used. The power output in these applications can be increased by raising the temperature of the gas entering the turbines. Turbine blades and vanes constrain the temperature of hot gases. For internal cooling design, techniques for heat extraction from the surfaces exposed to hot stream are based on increasing heat transfer areas and the promotion of turbulence of the cooling flow. Heat transfer is enhanced for example due to ribs, bends, rotation and buoyancy effects; all characterizes flow within the channels. Computational Fluid Dynamics (CFD) simulations are carried out using turbulence models like Large Eddy Simulation (LES) and Reynolds stress model (RSM). These CFD simulations were based on advanced computing technology to improve the accuracy of three-dimensional metal temperature prediction that can be applied routinely in the design stage of turbine cooled vanes and blades. The present work is done to study the effect of secondary flow due to the presence of ribs on heat transfer. In this paper, it is obtained by casting repeated continuous V and broken V-shaped ribs on one side of the two passes square channel into the core of blade. Two different combinations of 60° V and Broken 60° V-ribs in the channel are considered. This work is an attempt to collect information about Nusselt number inside the ribbed duct. Large Eddy Simulation (LES) is carried out on the Inlet V and Inverted V outlet continuous and Broken Inlet V and Inverted V-rib arrangements to analyze the flow pattern inside the channel. Hybrid LES/Reynolds Averaged Navier-Strokes (RANS) modeling is used to modify Reynolds stresses using Algebraic Stress Model (ASM), and a CFD strategy is proposed to predict heat transfer across the cooling channel.

Large Eddy Simulation of Round Impinging Jets With Large Stand-Off Distance

2014 ◽  
Author(s):  
Mehrdad Shademan ◽  
Vesselina Roussinova ◽  
Ron Barron ◽  
Ram Balachandar
Keyword(s):  
Large Eddy Simulation ◽  
Flow Characteristics ◽  
Impinging Jet ◽  
Impinging Jets ◽  
Vortical Structures ◽  
Nozzle Height ◽  
Eddy Simulation ◽  
Large Eddy ◽  
The Mean ◽  
Good Agreement

Large Eddy Simulation (LES) has been carried out to study the flow of a turbulent impinging jet with large nozzle height-to-diameter ratio. The dynamic Smagorinsky model was used to simulate the subgrid-scale stresses. The jet exit Reynolds number is 28,000. The study presents a detailed evaluation of the flow characteristics of an impinging jet with nozzle height of 20 diameters above the plate. Results of the mean normalized centerline velocity and wall shear stress show good agreement with previous experiments. Analysis of the flow field shows that vortical structures generated due to the Kelvin-Helmholtz instabilities in the shear flow close to the nozzle undergo break down or merging when moving towards the plate. Unlike impinging jets with small stand-off distance where the ring-like vortices keep their interconnected shape upon reaching the plate, no sign of interconnection was observed on the plate for this large stand-off distance. A large deflection of the jet axis was observed for this type of impinging jet when compared to the cases with small nozzle height-to-diameter ratios.

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