Search results

Simulation on balde duct vortex in a Francis turbine runner based on S-A model Yongzhong Zeng1,a and Xiaobing Liu1,b 1School of Energy and Environment, Xihua University, Chengdu, 610039, China azyzzyzhome@163.com, bliuxb @mail.xhu.edu.cn Keywords: Spalart-Allmaras model, blade duct vortex, low specific speed, turbine Abstract.
Introduction With the rapid development of computational fluid dynamics (CFD), the using of turbulence theory to calculate the flow field in the turbine runner has become a powerful tool for the hydraulic design and performance analysis of the runner, and the calculation results have been approved by[1,2] .
Numerical Simulation of Vortex Flow in Draft Tube of Turbine 3.1 Geometric model and grid A Francis turbine with long and short blades and with the model of HLA542-LJ-130 was used for the calculation.
[2] YUAN Shouqi, HE Youshi, YUAN Jianping, et al., PIV measurements and numerical simulations of flow in centrifugal pump impellers with splitting vanes, Chinese Journal of Mechanical Engineering, 42(5) (2006), pp.60-63
Bui, A parallel finite-volume algorithm for large-eddy simulation of turbulent flows, Computer & Fluids; 2000, 29: 877-915

With the help of CFD.
The numerical simulation method can solve the actual problem.
Numerical simulation of steady flow in vortex pump.
Optimization design and test of vortex pump based on CFD orthogonal test.
CFD-PBM coupled calculation on liquid-solid two-phase flow field in a vortex pump.

And the detailed comparison between numerical simulation and wind tunnel test is given.
The distribution of surface wind pressure and wind speed of Hangzhou bay bridge, offshore platform and sightseeing tower is numerically simulated based on Fluent of professional CFD software in this paper.
Numerical simulation Mathematical modeling.
Numerical simulation of laminar flow past a circular cylinder [J].
Numerical Simulation of Steady Flow around a 3D High-rise Building[J].

Bouquet, F. et al. (2001) [7] compares the thrust and specific impulse of igniters obtained from experimental analysis with numerical simulation.
Unstructured tetrahedral mesh is generated using ANSYS ICEM CFD.
CFD analysis is performed to obtain the fluid flow and mixing characteristics inside the each of the Igniter flow domains using ANSYS FLUENT 14.5.
Breussin, CFD Calculations on Hydrogen and Oxygen Combustion in Small Devices, 37th AIAA Joint Propulsion Conference, 2001-3712, (2001), pp. 1-9.

Performance analysis of the new helicopter-lift device Yueming Yang, Qinyu Yang, Jinbo Yao, Yuankai LI Air Force Aviation University, Changchun, 130022, China email:cyym1@126.com Keywords: Helicopter; Lift device; Aerodynamic characteristics; Numerical Simulation Abstract.
Based on 2D N-S equations and Spalart-Allmaras turbulence model, the device numerical simulation of two-dimensional aerodynamic characteristics.
This paper established a simplified model of the lift device, and its two-dimensional CFD numerical simulation and aerodynamic characteristics.
Simulation used solver; fluid material to the ideal gas; momentum using second-order upwind discretization scheme; pressure and velocity coupling the SIMPLE algorithm; airfoil surface is non-slip adiabatic boundary.
Beijing: 2005.9.1 [4] Hanzhan Zhong, Wang Jing,Lan xiaoping.FLUENT fluid engineering simulation and application examples [P].

Simulation of mixed convection around a square by using LBM A.
Chatterjee and Amiroudine [8] carried out simulation of mixed convection from tandem square obstacles to flow in order to explore the effect of buoyancy and Prandtl number on flow properties and heat transfer in various conditions as: 1≤Re≤30, 0.7≤ Pr ≤100 and 0≤Ri≤1.
The inherent advantages of lattice Boltzmann method such as simple calculation procedures, suitable for parallel computation, so on, create a great interest in researchers to accept LBM as alternative method to conventional CFD methods.
Nor Azwadi, "Cubic-Interpolated-Pseudo-Particle lattice Boltzmann method for simulation of natural convection heat transfer in an enclosure with different aspect ratios, “Computer and Automation Engineering, vol.5,268-273 (2010).

The Effects of Environment Wind on Heat Transfer Performance of Direct Air Cooled Island and Its Improvements Pei GAO a , Xuelei Zhang, Xinwei YU School of Energy, Power and Mechanical Engineering, North China Electric Power University, Baoding 071003, China agaopei88633@163.com Keywords: Air-cooling island; Windy conditions; Windproof net; Air-cooled Condenser Cell; Numerical simulation Abstract.
Using a CFD software, the numerical simulation of a 2×300MW direct air-cooled unit is done by multi-stage modeling method. the effect of the environmental wind on the heat-exchanging performance of the air-cooling island is analyzed by numerical simulation.
Fig.6 Under different wind speed change of volumetric efficiency Conclusions Taking 300MW direct air-cooled unit as an example, the effect of the environmental wind on the heat-exchanging performance of the air-cooling island is analyzed by numerical simulation.
References [1] Zhou Lan xin, Bai Zhong hua,Li Wei hua,et al.Numerical simulation for the effects of natural wind on heat exchange efficiency of air-cooled condenser[J].Journal of Power Engineering, 2008, 28(1): 104-107 [2] Zhao Wan li, Liu Pei qing.
Experimental researches of the effect of environmental wind on thermal recirculation under the tower of direct air cooled system[J].Journal of Power Engineering, 2008, 28(3), 390-394 [3] Zhou Lan xin, Li Jian bo, Li Wei hua, et al.Numerical simulation of direct air cooling units’ condenser added lower wind break[J].Journal of Power Engineering, 2008, 28(5): 744-747 [4] Zhang Xue lei , Wang Jin ping .

The active control method(jet flow) by applying the CFD technology based on Scale-Adaptive Simulation(SAS) model developed from two-equation SST turbulent model is used to simulate the changing of the dynamic noise in the standard cavity M219(the ratio of the length to the depth is 5), and studied the flow character, flow field structure and noise mechanism.
The SAS framework therefore offers an interesting approach for this type of simulation.
[4] Rowley C W, Cavity Flow Control Simulations and Experiments, AIAA-2005-0292
Egorov, The Scale-Adaptive Simulation Method for Unsteady Turbulent Flow Predictions.
[8] Chang K S, Hybrid RANS/LES Simulation of Deep Cavity Flow, AIAA-2004-53

The measured temperature values are compared with the results obtained from numerical simulation of the dynamic heat transport using non-stationary boundary conditions.
The value of heat flux determined by numerical simulation at the point between the columns is the same as the measured mean value of the local heat flux.
All results of simulation calculations have got sufficient accuracy.
Lausova, Experimental Measurement and Numerical Simulation of Dynamic Thermal Performance of External Timber Frame Wall.
Blejchar, M Bojko, M Kozubkova, CFD simulations of the effect of wind on the spontaneous heating of coal stockpiles, Fuel. 2014, vol. 118, pp. 107-112, ISSN 0016-2361, DOI: 10.1016/j.fuel.2013.10.064.

However, the simulation faces some difficulties.
Usually, the mishandling of grids will lead to the failure of simulation.
The computational accuracy of heat transfer in wall is of great importance to the precision of simulation.
The simulation result The first thermal boundary condition.
[2] Zhousan Cunshang:CFD and building environment design(China Architecture & Building Press, 2007)