Numerical Simulation of the 3D Turbulent Flow Field in a Cross-Flow Fan Used in the Air Conditioner

2012 ◽  
Vol 538-541 ◽  
pp. 462-465 ◽  
Author(s):  
Yong Chao Zhang ◽  
Qing Guang Chen ◽  
Wei Bin Wang ◽  
Bin Xie
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Turbulent Flow ◽  
3D Model ◽  
Cross Flow ◽  
Internal Flow ◽  
Air Conditioner ◽  
Full Field ◽  
Overall Performance ◽  
Cross Flow Fan

Aiming at a cross-flow fan used in some kind of air conditioner, the full field 3D model was built, and the numerical simulation of the inner turbulent flow under design condition is resented. The results display the characteristics of flow field in the cross-flow fan, especially the velocity field, pressure field and the velocity distributing before the evaporator. 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.

The Influence of Non-Uniform Impeller on the Cross Flow Fan Noise

2016 ◽  
Vol 693 ◽  
pp. 251-256
Author(s):  
Zhi Qiang Yang ◽  
C.J. Wu
Keyword(s):  
Pressure Fluctuations ◽  
Flow Characteristics ◽  
Cross Flow ◽  
Internal Flow ◽  
Broadband Noise ◽  
Aerodynamic Noise ◽  
Air Conditioner ◽  
Fan Noise ◽  
Power Spectral ◽  
Cross Flow Fan

The aerodynamic noise of a cross flow fan with uneven blade spacing in room air-conditioner was simulated by computational aerodynamic acoustics (CAA) method. It is detailed to analyze the vorticity distribution of the flow field and the power spectral density of measured points’ pressure fluctuations, and the results demonstrate the non-uniform impeller used in this paper can significantly improve internal flow characteristics. Thus the broadband noise got reduced.

Numerical Simulation and Experiment Research of the Whole Flow Field inside a Multi-Blade Centrifugal Fan

2012 ◽  
Vol 468-471 ◽  
pp. 2255-2258
Author(s):  
Feng Gao ◽  
Wei Yan Zhong
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Field Model ◽  
Pressure Field ◽  
Internal Flow ◽  
Centrifugal Fan ◽  
Simulation And Experiment ◽  
Overall Performance ◽  
Unsteady Numerical Simulation ◽  
Cfd Method

The full flow field model of a widely used multi-blade centrifugal was built, using the CFD method, the steady and unsteady numerical simulation of the inner flow in the fan at different working conditions are presented. The numerical simulation results were validated by contrasting to the experiment results. The results displayed the characteristics of the velocity field, pressure field and pressure fluctuate 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.

Aerodynamic and Aeroacoustic Performance of Cross Flow Fan With Inlet Guide Vane

2012 ◽  
Author(s):  
Jie Tian ◽  
Hua Ouyang ◽  
Kangjie Sun ◽  
Xiaocheng Zhu ◽  
Zhiming Zheng ◽  
...  
Keyword(s):  
Flow Field ◽  
Power Consumption ◽  
Flow Rate ◽  
Cross Flow ◽  
Internal Flow ◽  
Inlet Guide Vane ◽  
Inlet Flow ◽  
Blade Passing Frequency ◽  
Different Types ◽  
Cross Flow Fan

Effect of internal flow field and aeroacoustics of cross flow fan (CFF) with different types of inlet guide vanes (IGVs) is analyzed by experimental and numerical methods. With the base type of IGV (BA), pressure rise of CFF is increased at the same flow rate as the one without IGV (Prototype-No IGV). However, power consumption of CFF with IGV is also increased at the same flow rate. Moreover, total sound pressure level of CFF with IGV is highly increased by 9dBA and more than 15 dBA increase of SPL is also found at the first three harmonics of blade passing frequency of CFF. Internal flow field of CFF with different types of IGVs is analyzed by numerical method. Design method of IGV used in CFF is discussed based on simulated results and improved IGV (OP) is manufactured and measured. Compared with BA, OP has lower flow rate and highly decreased noise not only in total SPL but also in the first three harmonics of blade passing frequency. Compared with the prototype, OP has a little larger noise but lower power consumption benefit at the same flow rate. According to the analysis, it can be concluded that inlet flow condition of CFF is improved with suitable IGV and inlet flow separation is reduced. Benefit of large decrease of power consumption with a little increase of noise penalty of CFF can be achieved with careful design of IGV. Moreover, alteration of airfoil in CFF from single arc to more complex airfoils is convenient to design with the help of IGV.

scholarly journals Attenuation of Cross-Flow Fan Noise Using Porous Stabilizers

2011 ◽  
Vol 2011 ◽  
pp. 1-10 ◽  
Author(s):  
Huanxin Lai ◽  
Meng Wang ◽  
Chuye Yun ◽  
Jin Yao
Keyword(s):  
Cross Flow ◽  
Sound Radiation ◽  
Internal Flow ◽  
Considerable Effect ◽  
Front Wall ◽  
Performance Curve ◽  
Fan Noise ◽  
Aerodynamic Performances ◽  
The Cross ◽  
Cross Flow Fan

This paper presents a qualitative analysis of controlling the cross-flow fan noise by using porous stabilizers. The stabilizer was originally a folded plate. It is changed into a porous structure which has a plenum chamber and vent holes on the front wall. In order to investigate the influences of using the porous stabilizers, experiments are carried out to measure the cross-flow fan aerodynamic performances and sound radiation. Meanwhile, the internal flow field of the fan is numerically simulated. The results show that the porous stabilizers have not produced considerable effect on the cross-flow fan's performance curve, but the noise radiated from the fan is strongly affected. This indicates the feasibility of controlling the cross-flow fan noise by using the porous stabilizers with selected porosity.

scholarly journals Role of Transient Characteristics in Fish Trajectory Modeling

2020 ◽  
Author(s):  
zhu gao ◽  
zu hao zhou ◽  
Helge I Andersson
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Turbulent Flow ◽  
Transient Flow ◽  
Simultaneous Recording ◽  
Fish Locomotion ◽  
Vertical Slot ◽  
Turbulent Flow Structure ◽  
General Method

In this paper, we analyzed the live fish trajectory recorded from an experiment in an experimental vertical slot fishway. Combined with a numerical simulation, we demonstrated that randomness shown in fish trajectory might not merely be attributed to fish's random choices in its swimming, also could be an adaption consequence to the bulk unsteady turbulent flow structure. Simple superposing the fish trajectory on the time-averaged flow field obtained either by interpolating on discrete point measurements or numerical simulation is not an ideal method for fish movement description in fishway engineering. How to model the fish paths in transient flow and the necessity of simultaneous recording of the flow field and the fish locomotion are challenging topics. The suggested spectrum analysis of the flow field may provide a new general method to reproduce the fish trajectory in a complex turbulent flow.

Development of High Efficiency and Low Noise Cross-Flow Fans for Room Air Conditioner Indoor Unit

2014 ◽  
Author(s):  
Hironobu Yamakawa
Keyword(s):  
High Efficiency ◽  
Length Distribution ◽  
Cross Flow ◽  
Low Noise ◽  
Navier Stokes ◽  
Outer Diameter ◽  
Air Conditioner ◽  
Blade Edge ◽  
Sinusoidal Shape ◽  
Cross Flow Fan

Cross flow fans are used for fan systems in a household room air conditioner indoor unit. In recently, in the view of environmental problem and cost saving, energy saving performance is important specification for users. Reducing fan motor electric power consumption is effective for this purpose. And also low noise fans are needed for comfortable circumferences. To meet these user needs, we developed a high efficiency and silent cross flow fan using CFD (Computational Fluid Dynamics) and experiments. In CFD, numerical model is calculated by commercial software using steady state, Reynolds-averaged Navier-Stokes (RANS) and k-ε turbulent flow model. The developed cross flow fan is geometrically characterized by the solidity (the ratio of the blade pitch and blade cord length) distribution, and the blade edge shape. The solidity average of developed fan was larger than the conventional fan and the solidity distribution was smooth. And the developed fan has the sinusoidal shape of the outer diameter edge. This sinusoidal shape edge makes pressure distribution on the tongue to be more dispersed compare to that of conventional straight edge so that tonal noise was restrained.

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