scholarly journals Numerical Simulation of Air Entrainment Performance of a Foam Generator Used for Dust Control in Coal Mines

2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
Hetang Wang ◽  
Yan Tang
Keyword(s):  
Numerical Simulation ◽  
Cfd Simulation ◽  
High Reliability ◽  
Coal Mines ◽  
Air Entrainment ◽  
Dust Control ◽  
Predicted Values ◽  
Foam Generator ◽  
Cfd Method ◽  
Contraction Angle

Mine dust is one of the most serious environmental hazards in the coal mining process. This paper introduces a numerical simulation of a novel foam generator used for dust control in coal mines. The amount of foam generated by this device significantly depends on the amount of air entrainment. Therefore, a computational fluid dynamics (CFD) method was used to study three influencing factors, namely, throat-nozzle distance, mixing throat length, and the contraction angle of the suction chamber. The predicted values by the CFD simulation proved to be in good agreement with the experimental data. The results revealed that the air entrainment reached its maximum when the ratio of throat-nozzle distance to mixing throat length was 2/3. The optimum values of the throat ratio (its length to diameter) and the contraction angle of the suction chamber were obtained at 20 and 5°, respectively. This research provides essential guidance in the geometric parameter design of the self-suction type foam generator, which has the advantage of negating the need for compressed-air pipelines and having high reliability, compared to traditional foam generators.

Hydraulic Characteristics of the New Type Bulb Turbine With Micro-Head

2013 ◽  
Author(s):  
Lingyu Li ◽  
Yuan Zheng ◽  
Daqing Zhou ◽  
Zihao Mi
Keyword(s):  
Numerical Simulation ◽  
Cfd Simulation ◽  
Guide Vane ◽  
Three Dimensional ◽  
Flow Distribution ◽  
Three Dimensions ◽  
Guide Vanes ◽  
Runner Blade ◽  
Cfd Method ◽  
Bulb Turbine

The head of low-head hydropower stations is generally higher than 2.5m in the world, while micro-head hydropower resources which head is less than 2.5m are also very rich. In the paper, three-dimensional CFD method has been used to simulate flow passage of the micro-head bulb turbine. The design head and unit flow of the turbine was 1m and 3m3/s respectively. With the numerical simulation, the bulb turbine is researched by analyzing external characteristics of the bulb turbine, flow distribution before the runner, pressure distribution of the runner blade surface, and flow distribution of the outlet conduit under three different schemes. The turbine in second scheme was test by manufactured into a physical model. According to the results of numerical simulation and model test, bulb turbine with no guide vane in second scheme has simpler structure, lower cost, and better flow capacity than first scheme, which has traditional multi-guide vanes. Meanwhile, efficiency of second scheme has just little decrease. The results of three dimensions CFD simulation and test results agree well in second scheme, and higher efficiency is up to 77% which has a wider area with the head of 1m. The curved supports in third scheme are combined guide vanes to the fixed supports based on 2nd scheme. By the water circulations flowing along the curved supports which improve energy transformation ability of the runner, the efficiency of the turbine in third scheme is up to 82.6%. Third scheme, which has simpler structure and best performance, is appropriate for the development and utilization of micro-head hydropower resources in plains and oceans.

scholarly journals Simulation of vertical tidal turbine based on OpenFOAM and influence of inlet turbulence

2019 ◽  
Vol 272 ◽  
pp. 01017
Author(s):  
Liu Yun-ya ◽  
Yu-chen Yang ◽  
Ya-wen Yang
Keyword(s):  
Numerical Simulation ◽  
Turbulence Model ◽  
Cfd Simulation ◽  
Vertical Axis ◽  
Simulation Method ◽  
Hydrodynamic Characteristics ◽  
Numerical Simulation Method ◽  
Tidal Turbine ◽  
Cfd Method ◽  
Control Equation

This paper first introduces the basic theory of CFD method, including basic control equations, finite volume method, control equation solving algorithm and turbulence model selection. Second, based on OpenFOAM, an open-source fluid mechanics software, a numerical simulation method of vertical axis tidal turbine was proposed by using k-ω SST turbulence model and PIMPLE algorithm. The hydrodynamic characteristics of the vertical axis turbine were studied, and the calculation results were compared with experiments. The higher consistency proves the feasibility of the numerical simulation method proposed in this paper. Finally, the influence of inlet turbulence on numerical simulation was explored, and a set of effective CFD simulation strategies was concluded, which provided a valuable reference for future CFD simulation and research on vertical axis tidal turbines.

Numerical Simulation and Structure Optimization of Converter Gas Evaporative Cooler

2013 ◽  
Author(s):  
Zeyi Jiang ◽  
Pengyuan Chen ◽  
Pan Liu ◽  
Guanghe Tian
Keyword(s):  
Numerical Simulation ◽  
Mass Transfer ◽  
Cfd Simulation ◽  
Engineering Application ◽  
Discrete Phase Model ◽  
Engineering Project ◽  
Two Phase ◽  
Flow Process ◽  
Evaporative Cooler ◽  
Cfd Method

In Lurgi-Thyssen dedusting system of steelmaking converter, the evaporative cooler represents a crucial operating unit, in which the hot dust-laden flue gas has to be cooled by saturation with water. The cooling process of the gas consists of gas-liquid two phase flow and interphase heat and mass transfer. In this paper, k-epsilon standard equations and Lagrange discrete phase model are employed to describe the gas turbulent flow and the heat/mass transfer with droplet evaporation individually. The computational fluid dynamics (CFD) simulation for practical engineering project shows that the large-flux cooling gas is commonly constructed in a non-uniform flow caused by the sharp turnings at the inlet and outlet channels. The unevenness of velocity distribution and the effective cooling height are defined in this paper to evaluate the cooling flow process. A series of newly designed structures with guide plate are investigated by CFD method to eliminate the problems with the non-uniformity. The results of numerical simulation show that optimal designed guide ring plate could improve the flow uniformity and the heat transfer. The investigations have been used to guide the engineering application.

Hardware analysis of coal mines dust control

2017 ◽  
pp. 46-52
Author(s):  
S.S. Kubrin ◽  
◽  
S.N. Reshetniak ◽  
E.S. Ivanov ◽  
V.V. Degterev ◽  
...  
Keyword(s):  
Coal Mines ◽  
Dust Control

scholarly journals Two-phase CFD simulation of the monodyspersed suspension hydraulic behaviour in the tank apparatus from a circulatory pipe

2008 ◽  
Vol 10 (1) ◽  
pp. 22-27 ◽  
Author(s):  
Roch Plewik ◽  
Piotr Synowiec ◽  
Janusz Wójcik
Keyword(s):  
Cfd Simulation ◽  
Fluidised Bed ◽  
Cfd Simulations ◽  
Two Phase ◽  
Hydraulic Behaviour ◽  
Hydraulic Conditions ◽  
The One ◽  
Cfd Method ◽  
Multi Phase ◽  
The Ideal

Two-phase CFD simulation of the monodyspersed suspension hydraulic behaviour in the tank apparatus from a circulatory pipe The hydrodynamics in fluidized-bed crystallizers is studied by CFD method. The simulations were performed by a commercial packet of computational fluid dynamics Fluent 6.x. For the one-phase modelling (15), a standard k-ε model was applied. In the case of the two-phase flows the Eulerian multi-phase model with a standard k-ε method, aided by the k-ε dispersed model for viscosity, has been used respectively. The collected data put a new light on the suspension flow behaviour in the annular zone of the fluidised bed crystallizer. From the presented here CFD simulations, it clearly issues that the real hydraulic conditions in the fluidised bed crystallizers are far from the ideal ones.

scholarly journals The study of the numerical diffusion in computational calculation

2020 ◽  
Vol 310 ◽  
pp. 00039
Author(s):  
Kamila Kotrasova ◽  
Vladimira Michalcova
Keyword(s):  
Heat Transfer ◽  
Differential Equation ◽  
Numerical Simulation ◽  
Continuity Equation ◽  
Cfd Simulation ◽  
Flow Process ◽  
Ansys Fluent ◽  
Numerical Diffusion ◽  
Mesh Density ◽  
Computational Calculation

The numerical simulation of flow process and heat transfer phenomena demands the solution of continuous differential equation and energy-conservation equations coupled with the continuity equation. The choosing of computation parameters in numerical simulation of computation domain have influence on accuracy of obtained results. The choose parameters, as mesh density, mesh type and computation procedures, for the numerical diffusion of computation domain were analysed and compared. The CFD simulation in ANSYS – Fluent was used for numerical simulation of 3D stational temperature flow of the computation domain.

3D Numerical Simulation of the Process of Draining into a Lock

2013 ◽  
Vol 838-841 ◽  
pp. 1667-1670
Author(s):  
Ming Hua Deng ◽  
Zhu Gao ◽  
Da Wei Mao
Keyword(s):  
Numerical Simulation ◽  
Integral Method ◽  
Full Time ◽  
Inertia Effect ◽  
3D Numerical Simulation ◽  
Precise Estimation ◽  
Practical Engineering ◽  
Order Of Magnitude ◽  
Cfd Method ◽  
Ship Lock

In some textbooks, the Steady-flow Integral Method (SIM) was used to compute the full time of Draining into a Ship Lock, although this method is simple, it only provides a coarse estimation and somehow misleads the students due to approximating the unsteady problem as a steady one and ignoring the inertia effect. The more complex CFD-based model, FLUENT, was used to compensate these shortcomings, the Volume of Fluid (VOF) method was utilized to calculate the free-surface, and the turbulence closure was obtained by the realizable k-ε turbulence model. The values of draining time derived from the two different methods have the same order of magnitude. By CFD, a more precise estimation of the draining time and abundant details about the draining process were obtained. In practical engineering, the geometry of a lock is far more complex than here, the SIM is hard to satisfy the demands for a optimal design, while the CFD method is a nice choice for this purpose.

Numerical Simulation of Gas Flow and Heat Transfer in Cross-Wavy Primary Surface Channel for Microtubine Recuperators

2005 ◽  
Author(s):  
H. X. Liang ◽  
Q. W. Wang ◽  
L. Q. Luo ◽  
Z. P. Feng
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Gas Turbine ◽  
Numerical Study ◽  
High Reliability ◽  
Three Dimensional ◽  
Operating Conditions ◽  
Flow And Heat Transfer ◽  
High Heat Transfer ◽  
The Cross

Three-dimensional numerical simulation was conducted to investigate the flow field and heat transfer performance of the Cross-Wavy Primary Surface (CWPS) recuperators for microturbines. Using high-effective compact recuperators to achieve high thermal efficiency is one of the key techniques in the development of microturbine in recent years. Recuperators need to have minimum volume and weight, high reliability and durability. Most important of all, they need to have high thermal-effectiveness and low pressure-losses so that the gas turbine system can achieve high thermal performances. These requirements have attracted some research efforts in designing and implementing low-cost and compact recuperators for gas turbine engines recently. One of the promising techniques to achieve this goal is the so-called primary surface channels with small hydraulic dimensions. In this paper, we conducted a three-dimensional numerical study of flow and heat transfer for the Cross-Wavy Primary Surface (CWPS) channels with two different geometries. In the CWPS configurations the secondary flow is created by means of curved and interrupted surfaces, which may disturb the thermal boundary layers and thus improve the thermal performances of the channels. To facilitate comparison, we chose the identical hydraulic diameters for the above four CWPS channels. Since our experiments on real recuperators showed that the Reynolds number ranges from 150 to 500 under the operating conditions, we implemented all the simulations under laminar flow situations. By analyzing the correlations of Nusselt numbers and friction factors vs. Reynolds numbers of the four CWPS channels, we found that the CWPS channels have superior and comprehensive thermal performance with high compactness, i.e., high heat transfer area to volume ratio, indicating excellent commercialized application in the compact recuperators.

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