K-1514 Numerical Analysis for the Air Flow of Cross-Flow Fan : Development of the Inner Unit of an Air Conditioner

2001 ◽  
Vol II.01.1 (0) ◽  
pp. 301-302
Author(s):  
Hirokazu SAKAI ◽  
Satoshi TOKUSHIGE
Author(s):  
Hironobu Yamakawa

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.


2016 ◽  
Vol 693 ◽  
pp. 251-256
Author(s):  
Zhi Qiang Yang ◽  
C.J. Wu

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.


2008 ◽  
Vol 28 (14-15) ◽  
pp. 1853-1864 ◽  
Author(s):  
Yang-Cheng Shih ◽  
Hung-Chi Hou ◽  
Hsucheng Chiang

2012 ◽  
Vol 538-541 ◽  
pp. 462-465 ◽  
Author(s):  
Yong Chao Zhang ◽  
Qing Guang Chen ◽  
Wei Bin Wang ◽  
Bin Xie

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.


2012 ◽  
Vol 58 (2) ◽  
Author(s):  
New Mei Yet ◽  
Vijay R. Raghavan ◽  
W.M. Chin

A detailed characterization is carried out on a typical cross flow fan used in the Heating, Ventilation, and Air Conditioning (HVAC) industry, in order to understand the fan design in detail. The study is carried out numerically by use of the software FLUENT and followed by experimental validation. Appropriate grid size selection has done, the RMS error is less than 7%. From the study, it is concluded that the thickness of the blade determines the total flow area and flow rate delivered. When the internal blade angle is at 90°, shock free entry is incurred and maximum flow rate can be achieved. The external blade angle should be within 20 to 45 degrees, to avoid rapid drop of pressure coefficient and efficiency. Lastly, the formation of the eccentric vortex zone inside the cross flow fan and flow field pattern are observed. The forming location and size of the zone determines the total air flow rate delivered and the amount of flow leakage through the tongue. Thus, the efficiency of the fan is highly sensitive to the flow structure in this zone.


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