Correction: Parameter Study of a Porous Trailing Edge Using Improved Delayed Detached Eddy Simulation

2021 ◽  
Author(s):  
Yuejun Shi ◽  
Wolfgang Kollmann
2013 ◽  
Vol 444-445 ◽  
pp. 374-379 ◽  
Author(s):  
Lei Qiao ◽  
Jun Qiang Bai ◽  
Jun Hua ◽  
Chen Wang

The present article describes the combination of the correlation based transition model of Menter et al. with the Detached Eddy Simulation (DES) and Delayed Detached Eddy Simulation (DDES) methodology. The interaction between transition model and DES or DDES method was investigated by T3A test case. The grid sensitivity of the combined methodology is discussed and the resolution is given. Then, the simulation of flow over foil of medium thick at stall angle was performed. The combined methodology produce results that have better agreement with experiment comparing to RANS transition model or fully turbulent DES/DDES alone. And the DDES based combined model shows a better agreement with experiment in the simulation of trailing edge separation comparing to DES based combined model.


Author(s):  
Elizaveta Ivanova ◽  
Gregory M. Laskowski

This paper presents the results of a numerical study on the predictive capabilities of Large Eddy Simulation (LES) and hybrid RANS/LES methods for heat transfer, mean velocity, and turbulence in a fundamental trailing edge slot. The geometry represents a landless slot (two-dimensional wall jet) with adjustable slot lip thickness. The reference experimental data taken from the publications of Kacker and Whitelaw [1] [2] [3] [4] contains the adiabatic wall effectiveness together with the velocity and the Reynolds-stress profiles for various blowing ratios and slot lip thicknesses. The simulations were conducted at three different lip thickness and several blowing ratio values. The comparison with the experimental data shows a general advantage of LES and hybrid RANS/LES methods against unsteady RANS. The predictive capability of the tested LES models (dynamic ksgs-equation [5] and WALE [6]) was comparable. The Improved Delayed Detached Eddy Simulation (IDDES) hybrid method [7] also shows satisfactory agreement with the experimental data. In addition to the described baseline investigations, the influence of the inlet turbulence boundary conditions and their implication for the initial mixing layer and heat transfer development were studied for both LES and IDDES.


Author(s):  
Elizaveta Ivanova ◽  
Gustavo Ledezma ◽  
Guanghua Wang ◽  
Gregory M. Laskowski

This paper presents the results of a numerical study on the predictive capabilities of Large Eddy Simulation (LES) and hybrid RANS/LES methods for heat transfer in the trailing edge (TE) geometry experimentally investigated in Part 1. The experimental validation data includes 2D wall contours and laterally-averaged values of adiabatic cooling effectiveness. The simulations were conducted at three different blowing ratio values. The comparison with the experimental data shows a general advantage of LES and hybrid RANS/LES methods against steady-state RANS. The results obtained by means of the WALE LES model and the Improved Delayed Detached Eddy Simulation (IDDES) hybrid RANS/LES method were comparable. The presented grid dependence study shows the importance of adequate grid resolution for the predictive capabilities of trailing edge cooling LES. Furthermore, the importance of considering TE slot lands simulation quality in the numerical method assessment is discussed. Potential directions of future research needed to improve simulation reliability are outlined.


Author(s):  
Xiaoshuai Huo ◽  
Tanghong Liu ◽  
Miao Yu ◽  
Zhengwei Chen ◽  
Zijian Guo ◽  
...  

Wind tunnel tests for trains under large yaw angles are usually limited due to the width of the wind tunnel. Therefore, the leading car and a downstream dummy vehicle model are often employed instead of a real train, but there are no clear regulations regarding the shape of the end of the dummy vehicle. This paper studied the impact of the trailing edge shape of the downstream dummy vehicle on train aerodynamics subjected to crosswind based on the shear-stress-transport k-ω turbulence model of the delayed detached eddy simulation. Three types of end shapes, namely the rectangular end shape, the arc end shape, and the streamlined end shape were chosen for comparison, and the simulation results of the three-car-group train were selected as the benchmark. First, the reliability of the numerical method was validated by wind tunnel tests. Then, the aerodynamic coefficients under yaw angles of 0°–60° and the surface pressure distributions and flow structures around the train under the yaw angle of 60° of the head cars with different end shapes were compared and analyzed.


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