Numerical simulation of unsteady-state particle dispersion in ferroalloy workshop

Proceedings of the Institution of Mechanical Engineers, Part F:

et al. 2018

When high-speed trains run on a snowy railway line in cold weather, a large amount of snow and ice will accumulate on the brake calipers, which can lead to huge safety problems. In this paper, to solve this issue, a numerical method based on the detached eddy simulation was used to explore the flow features of a high-speed train running in cold weather. The accuracy of mesh resolution and methodology of Computational Fluid Dynamics (CFD) was validated against the wind tunnel tests. A discrete phase model was used to investigate the process of snow accumulation on the brake calipers by analysing the movement characteristics of snow particles. Based on this analysis, three kinds of anti-snow packing shields for the brake calipers were designed, and the shielding effects were compared via numerical simulations. The results show that a large amount of snow particles below the bogie directly impact the brake calipers causing massive snow packing on the bottom surfaces; some snow particles reflected from the rear equipment cabin cover return to the bogie region and accumulates on the upper surfaces. With the application of anti-snow packing shields with trapezoidal-, triangular- and cambered-shaped openings, the rates of snow accumulation on the brake calipers were reduced by 18.53, 26.68 and 38.81%, respectively. The cambered type provides the best anti-snow packing performance for the brake calipers.

Section: Introductionmentioning

confidence: 83%

Anti-snow performance of snow shields designed for brake calipers of a high-speed train

Wang

Gao

Proceedings of the Institution of Mechanical Engineers, Part F:

et al. 2018

“…So, the DPM is a good choice to solve this gas-solid two-phase flow problem (Ansari, Goharrizi, Jafari, & Abolpour, 2015;Kosinski & Hoffmann, 2007;Pankajakshan, Mitchell, & Taylor, 2011;Zhou, Mo, & Cen, 2011). Zhou, Flamant, Gauthier, and Lu (2004), Wan, Peng, Xie, Zhang, and Huang (2013), Ma, Liu, Li, Huang, and Su (2015), Liu et al (2015), Oh, Choi, and Kim (2015), Guizani, Mokni, Mhiri, and Bournot (2014), Baghdar Hosseini, Haghighi Khoshkhoo, and Javadi Malabad (2017), Xie et al (2017) and Gao (2018a, 2018b) used the DPM to simulate the motion of particles in the airflow, and the simulation results were in accord to their experiment results. Therefore, it is reasonable to use the DPM method to research the movement of dust particles in the settling chamber.…”

Section: Airflow Field Dynamics Modelmentioning

confidence: 99%

Study on the key structure parameters of a gravity settling chamber based on a flow field simulation

Liu

Engineering Applications of Computational Fluid Mechanics

et al. 2019

A gravity settling chamber plays an important role in improving the effect of the dust removal when it is selected as a dust collector in a pneumatic cleaning system for cleaning a subway tunnel. The settling rate and the indexes evaluating the secondary blowing are studied to assess the effect of the dust removal in this paper. Regarding the length of the settling chamber, the height of the inlet duct, and the diameter and height of the outlet duct as the variables of the key structures, a flow field simulation analysis of the gravity settling chamber with different heights of the dust accumulation is carried out, then the key structure parameters are optimized by means of the experimental method of uniform design. Finally, the settling chamber with an excellent dust removal effect is obtained. Major conclusions can be drawn as follows. (1) The maximum velocity and the mean velocity ratio of the airflow near a dust accumulation surface are important evaluation indexes for judging the secondary blowing. (2) The maximum velocity near a dust accumulation surface usually doesn't appear on the vertical plane through the axis of the inlet duct or the outlet duct. (3) An excellent settling effect can be ensured during the whole cleaning process only when the maximum design height of the dust-accumulation surface is considered as a key working condition. (4) An excellent settling effect can be realized if the settling chamber without any filtering device and affiliated baffle structure are long enough. (5) The secondary blowing can be avoided if the inlet and outlet of the setting chamber are far away from the dust-accumulation surface. This study has a good guiding significance for the design of gravity settling chamber.

“…11,13,14 Therefore, in this paper, it is reasonable to use the DPM based on the Euler–Lagrange method to study the effect of snow accumulation on the bogie, as the volume fraction of snow particles is far less than 10%. 35,36…”

Section: Mathematical Model and Validationmentioning

confidence: 99%

Numerical study on the anti-snow performance of deflectors in the bogie region of a high-speed train using the discrete phase model

Gao

Proceedings of the Institution of Mechanical Engineers, Part F:

Xie

et al. 2018

In this paper, the three-dimensional unsteady Reynolds-averaged Navier-Stokes equations with an RNG double-equation turbulence model and a discrete phase model were used for the investigation of snow accumulation on the bogie of a high-speed train. Two kinds of deflector plates, one installed at the front end and the other at the rear end of the bogie, were proposed to reduce snow accumulation. The accuracy of the CFD methodology was validated against wind tunnel tests. The results showed that high-speed air will impact the plates where snow particles get accumulated. The snow covering on the bogie rarely drifts back into the bogie region with air. The amount of accumulating snow in the optimum models is reduced by 50.58% on average as compared to those in the original models. At the rear end of the bogie, the inclined deflector plate reduced snow accumulation by up to 10.91% compared to the vertical deflector plate.