Simulation of near-field dispersion of pollutants using detached-eddy simulation

2014 ◽  
Vol 100 ◽  
pp. 308-320 ◽  
Author(s):  
M. Lateb ◽  
C. Masson ◽  
T. Stathopoulos ◽  
C. Bédard
Keyword(s):  
Near Field ◽  
Detached Eddy Simulation ◽  
Eddy Simulation

scholarly journals Low-Cost Eddy-Resolving Simulation in the Near-Field of an Annular Swirling Jet for Spray Drying Applications

2021 ◽  
Vol 5 (4) ◽  
pp. 80
Author(s):  
Jairo Andrés Gutiérrez Suárez ◽  
Alexánder Gómez Mejía ◽  
Carlos Humberto Galeano Urueña
Keyword(s):  
Spray Drying ◽  
Laser Doppler Anemometry ◽  
Low Cost ◽  
Near Field ◽  
Computational Cost ◽  
Individual Performance ◽  
Industrial Applications ◽  
Detached Eddy Simulation ◽  
Eddy Simulation ◽  
Swirling Jet

Spray drying is one of many industrial applications that use annular swirling jets. For this particular application, the flow characteristics in the near-field of the jet are fundamental to obtaining high-quality dried products. In this article, an annular swirling jet configuration is numerically studied using three low-cost eddy-resolving turbulence methods: detached-eddy simulation (DES), delayed-DES (DDES) and scale-adaptive simulation (SAS). To focus in industrial applicability, very coarse grids are used. The individual performance of these models is assessed through a comparison with laser-Doppler anemometry (LDA) measurements and large-eddy simulation (LES) data from available studies. Results show that all the three turbulence models are suitable for performing industrial cost-effective simulations, capable of reproducing LES results of mean velocities and first-order turbulence statistics at a fraction of the computational cost. Differences in the results of the evaluated models were minor; however, the simulation with DDES still provided a better reproduction of experimental results, especially in the very-near field of the jet, as it enforced RANS behavior near the inlet walls and a better transition from modeled to resolved scales.

Detached-eddy simulation of wing-tip vortex in the near field of NACA 0015 airfoil

2014 ◽  
Vol 26 (2) ◽  
pp. 199-206 ◽  
Author(s):  
Zhi-cheng Liang ◽  
Lei-ping Xue
Keyword(s):  
Near Field ◽  
Tip Vortex ◽  
Detached Eddy Simulation ◽  
Eddy Simulation ◽  
Wing Tip Vortex ◽  
Naca 0015 ◽  
Wing Tip

scholarly journals Near-Field Simulations of Film Cooling with a Modified DES Model

Inventions ◽  
2020 ◽  
Vol 5 (1) ◽  
pp. 13
Author(s):  
Feiyan Yu ◽  
Savas Yavuzkurt
Keyword(s):  
Film Cooling ◽  
Eddy Viscosity ◽  
Near Field ◽  
Computational Cost ◽  
Vortex Pair ◽  
Anisotropy Ratio ◽  
Detached Eddy Simulation ◽  
Film Cooling Effectiveness ◽  
Eddy Simulation ◽  
Des Model

Modeling the heat transfer characteristics of highly turbulent flow in gas turbine film cooling is important for providing better insights and engineering solutions to the film cooling problem. This study proposes a modified detached eddy simulation (DES) model for better film cooling simulations. First, spatially varying anisotropic eddy viscosity is found from the results of the large eddy simulation (LES) of film cooling. Then the correlation for eddy viscosity anisotropy ratio has been established based on the LES results and is proposed as the modification approach for the DES model. The modified DES model has been tested for the near-field film cooling simulations under different blowing ratios. Detailed comparisons of the centerline and 2D film cooling effectiveness indicate that the modified DES model enhances the spanwise spreading of the temperature field. The DES model leads to deviations of 62.4%, 39.8%, and 33.5% from the experimental centerline effectiveness under blowing ratios of 0.5, 1.0, and 1.5, respectively, while the modified DES reduces the deviations to 51.5%, 26.7%, and 28.9%. The modified DES model provides a promising approach for film cooling numerical simulations. It embraces the advantage of LES in resolving detailed vortical structure dynamics with a moderate computational cost. It also significantly improves the original DES model on the spanwise counter rotating vortex pair (CRVP) spreading, mixing, and effectiveness prediction.

Near-Field Noise Prediction for Landing Gear Based on Detached Eddy Simulations

2014 ◽  
Vol 472 ◽  
pp. 105-110
Author(s):  
Ning Hu ◽  
Xuan Hao ◽  
Cheng Su ◽  
Wei Min Zhang ◽  
Han Dong Ma
Keyword(s):  
Flow Field ◽  
Unsteady Flow ◽  
Sound Pressure ◽  
Near Field ◽  
Separated Flow ◽  
Landing Gear ◽  
Aerodynamic Noise ◽  
Noise Prediction ◽  
Detached Eddy Simulation ◽  
Eddy Simulation

A four-wheel rudimentary landing gear is studied numerically by detached eddy simulation (DES) based on the Spalart-Allmaras turbulence model. The surface sound pressure level and sound pressure spectra are calculated using the obtained unsteady flow field. The investigation shows that DES can describe the steady and unsteady properties in the flow around rudimentary landing gear. It can give reasonable results since the flow around the landing gear is a massive separated flow. The results prove the feasibility of DES type methods in massive separated unsteady flow field and aerodynamic noise prediction for landing gear, and can be used in the study of landing gear noise reduction.

High-Order Delayed Detached Eddy Simulation of Separated Flow with Self-Adaptive Dissipation

2020 ◽  
pp. 1-12
Author(s):  
Li Hao ◽  
Liu Wei ◽  
Wang Shengye ◽  
Wang Guangxue
Keyword(s):  
Separated Flow ◽  
High Order ◽  
Detached Eddy Simulation ◽  
Eddy Simulation ◽  
Delayed Detached Eddy Simulation ◽  
Self Adaptive

scholarly journals Assessing IDDES-Based Wall-Modeled Large-Eddy Simulation (WMLES) for Separated Flows with Heat Transfer

Fluids ◽  
2021 ◽  
Vol 6 (7) ◽  
pp. 246
Author(s):  
Rozie Zangeneh
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Large Eddy Simulation ◽  
Skin Friction ◽  
Heat Fluxes ◽  
Separated Flows ◽  
Detached Eddy Simulation ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Isothermal Wall

The Wall-modeled Large-eddy Simulation (WMLES) methods are commonly accompanied with an underprediction of the skin friction and a deviation of the velocity profile. The widely-used Improved Delayed Detached Eddy Simulation (IDDES) method is suggested to improve the prediction of the mean skin friction when it acts as WMLES, as claimed by the original authors. However, the model tested only on flow configurations with no heat transfer. This study takes a systematic approach to assess the performance of the IDDES model for separated flows with heat transfer. Separated flows on an isothermal wall and walls with mild and intense heat fluxes are considered. For the case of the wall with heat flux, the skin friction and Stanton number are underpredicted by the IDDES model however, the underprediction is less significant for the isothermal wall case. The simulations of the cases with intense wall heat transfer reveal an interesting dependence on the heat flux level supplied; as the heat flux increases, the IDDES model declines to predict the accurate skin friction.

Numerical study of the flow over the modified simple frigate shape

2020 ◽  
pp. 095441002097775
Author(s):  
Tong Li ◽  
Yibin Wang ◽  
Ning Zhao
Keyword(s):  
Bluff Body ◽  
Recirculation Zone ◽  
Numerical Study ◽  
Reference Value ◽  
Flow Fields ◽  
Navier Stokes ◽  
Detached Eddy Simulation ◽  
Eddy Simulation ◽  
Delayed Detached Eddy Simulation ◽  
Simulation Results

The simple frigate shape (SFS) as defined by The Technical Co-operative Program (TTCP), is a simplified model of the frigate, which helps to investigate the basic flow fields of a frigate. In this paper, the flow fields of the different modified SFS models, consisting of a bluff body superstructure and the deck, were numerically studied. A parametric study was conducted by varying both the superstructure length L and width B to investigate the recirculation zone behind the hangar. The size and the position of the recirculation zones were compared between different models. The numerical simulation results show that the size and the location of the recirculation zone are significantly affected by the superstructure length and width. The results obtained by Reynolds-averaged Navier-Stokes method were also compared well with both the time averaged Improved Delayed Detached-Eddy Simulation results and the experimental data. In addition, by varying the model size and inflow velocity, various flow fields were numerically studied, which indicated that the changing of Reynolds number has tiny effect on the variation of the dimensionless size of the recirculation zone. The results in this study have certain reference value for the design of the frigate superstructure.

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