Numerical Simulation and Experiment Research on Pressure Fluctuation and Aerodynamic Noise Field of a Multi-Blade Centrifugal Fan

2012 ◽  
Vol 468-471 ◽  
pp. 2231-2234
Author(s):  
Feng Gao ◽  
Wei Yan Zhong

Numerical simulation of the three-dimensional steady and unsteady turbulent flow in the whole flow field of a multi-blade centrifugal fan is performed. Unstructured grids is used to discrete the computational domain. Pressure boundary conditions are specified to the inlet and the outlet. The SIMPLE algorithm in conjunction with the RNG k-ε turbulent model is used to solve the three-dimensional Navier-Stokes equations. The moving reference frame is adopted to transfer data between the interfaces of the rotating field and the stationary field. Based on the calculation of the inner-flow in the fan, the pressure pulsation of some important monitoring points and the aerodynamic noise distribution, banding together experiment data were farther analyzed The simulation results are of important significance to the optimal design and noise control of the fan.

2011 ◽  
Vol 317-319 ◽  
pp. 2157-2161
Author(s):  
Yong Chao Zhang ◽  
Qing Guang Chen ◽  
Yong Jian Zhang ◽  
Xiang Xing Jia

The full flow field model of a widely used multi-blade centrifugal fan was built, and unstructured grids were used to discrete the computational domain. The moving reference frame is adopted to transfer data between the interfaces of the rotating field and the stationary field. Pressure boundary conditions are specified to the inlet and the outlet. The SIMPLE algorithm in conjunction with the RNG k-ε turbulent model was used to solve the three-dimensional Navier-Stokes equations. The steady and unsteady numerical simulations of the inner flow in the fan at different working conditions were presented using the CFD method. The numerical simulation results were validated by contrasting to the experiment results. The results displayed the characteristics of the velocity field, pressure field, pressure fluctuation at two monitoring points in the centrifugal fan. The results can provide basis for optimizing the fan design and the internal flow, and have important value of engineering applications in the increase of the overall performance in operation.


2004 ◽  
Vol 126 (5) ◽  
pp. 735-742 ◽  
Author(s):  
Kwang-Yong Kim ◽  
Seoung-Jin Seo

In this paper, the response surface method using a three-dimensional Navier-Stokes analysis to optimize the shape of a forward-curved-blade centrifugal fan is described. For the numerical analysis, Reynolds-averaged Navier-Stokes equations with the standard k-ε turbulence model are discretized with finite volume approximations. The SIMPLEC algorithm is used as a velocity–pressure correction procedure. In order to reduce the huge computing time due to a large number of blades in forward-curved-blade centrifugal fan, the flow inside of the fan is regarded as steady flow by introducing the impeller force models. Four design variables, i.e., location of cutoff, radius of cutoff, expansion angle of scroll, and width of impeller, were selected to optimize the shapes of scroll and blades. Data points for response evaluations were selected by D-optimal design, and a linear programming method was used for the optimization on the response surface. As a main result of the optimization, the efficiency was successfully improved. Effects of the relative size of the inactive zone at the exit of impeller and momentum fluxes of the flow in scroll on efficiency were further discussed. It was found that the optimization process provides a reliable design of this kind of fan with reasonable computing time.


2016 ◽  
pp. 92-97
Author(s):  
R. E. Volkov ◽  
A. G. Obukhov

The rectangular parallelepiped explicit difference schemes for the numerical solution of the complete built system of Navier-Stokes equations. These solutions describe the three-dimensional flow of a compressible viscous heat-conducting gas in a rising swirling flows, provided the forces of gravity and Coriolis. This assumes constancy of the coefficient of viscosity and thermal conductivity. The initial conditions are the features that are the exact analytical solution of the complete Navier-Stokes equations. Propose specific boundary conditions under which the upward flow of gas is modeled by blowing through the square hole in the upper surface of the computational domain. A variant of parallelization algorithm for calculating gas dynamic and energy characteristics. The results of calculations of gasdynamic parameters dependency on the speed of the vertical blowing by the time the flow of a steady state flow.


2013 ◽  
Vol 694-697 ◽  
pp. 56-60
Author(s):  
Yue Jun Ma ◽  
Ji Tao Zhao ◽  
Yu Min Yang

In the paper, on the basis of three-dimensional Reynolds-averaged Navier-Stokes equations and the RNG κ-ε turbulence model, adopting Three-dimensional unstructured grid and pressure connection the implicit correction SIMPLEC algorithm, and using MRF model which is supported by Fluent, this paper carries out numerical simulation of the internal flow of the centrifugal pump in different operation points. According to the results of numerical simulation, this paper analyzes the bad flow phenomena of the centrifugal pump, and puts forward suggests about configuration perfected of the centrifugal pump. In addition, this paper is also predicted the experimental value of the centrifugal pump performance, which is corresponding well with the measured value.


2013 ◽  
Vol 378 ◽  
pp. 418-423
Author(s):  
Gang Liu ◽  
Jia Wu ◽  
Wei Li

The three-dimensional construct of concentration field in an oscillatory flow reactor (OFR) containing periodically spaced conic ring baffles was investigated by numerical simulation employing Reynolds-averaged Navier-Stokes equations. The computation covered a range of Oscillatory Reynolds number (Reo) from 623.32 to 3116.58 at Strouhal number (St) 0.995 and 1.99. The contour of concentration field showed that the concentration in the most part of the channel is relative uniform and a small retention area is found below the conic ring baffles, which means a region of relative poor mixing. In addition, the turbulent diffusion coefficient calculated from the simulation results implied the greater oscillatory amplitude and oscillatory frequency superimposed to the fluid, the stronger is the turbulence intensity.


Author(s):  
Jianjun Liu

This paper describes the numerical simulation of the asymmetric exhaust flows by using a 3D viscous flow solver incorporating an actuator disc blade row model. The three dimensional Reynolds-Averaged Navier-Stokes equations are solved by using the TVD Lax-Wendroff scheme. The convergence to a steady state is speeded up by using the V-cycle multigrid algorithm. Turbulence eddy viscosity is estimated by the Baldwin-Lomax model. Multiblock method is applied to cope with the complicated physical domains. Actuator disc model is used to represent a turbine blade row and to achieve the required flow turning and entropy rise across the blade row. The solution procedure and the actuator disc boundary conditions are described. The stream traces in various sections of the exhaust hood are presented to demonstrate the complicity of the flow patterns existing in the exhaust hood.


2006 ◽  
Vol 28 (3) ◽  
pp. 134-144
Author(s):  
Nguyen The Duc

The paper presents a numerical method to simulate two-phase turbulent cavitating flows in ducts of varying cross-section usually faced in engineering. The method is based on solution of two-phase Reynolds-averaged Navier-Stokes equations of two-phase mixture. The numerical method uses artificial compressibility algorithm extended to unsteady flows with dual-time technique. The discreted method employs an implicit, characteristic-based upwind differencing scheme in the curvilinear grid systems. Numerical simulation of an unsteady three-dimensional two-phase cavitating flow in a duct of varying cross-section with available experiment was performed. The unsteady important characteristics of the unsteady flow can be observed in results of numerical simulation. Comparison of predicted results with experimental data for time-averaged velocity and phase fraction are provided.


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