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.

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.

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.

A physics-based zero-dimensional model for the mass flow rate of a turbocharger compressor with uniform/distorted inlet condition

2018 ◽  
Vol 20 (6) ◽  
pp. 624-639 ◽  
Author(s):  
Kang Song ◽  
Ben Zhao ◽  
Harold Sun ◽  
Weilin Yi
Keyword(s):  
Flow Field ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Fluid Dynamic ◽  
Dimensional Model ◽  
Inlet Pipe ◽  
External Work ◽  
Compressor Wheel ◽  
Inlet Flow

Turbocharger compressor, when fitted to a vehicle, usually operates with a curved inlet pipe which leads to distorted inlet flow field, hence deteriorating compressor flow capability. During the measurement of compressor performance, turbocharger-engine matching and controller design, the inlet flow field is, however, assumed to be uniform, which deviates from the real-world conditions. Consequently, the overall system performance could be compromised if the inlet distortion effect is ignored. To address this issue, in this article, a turbomachinery physics-based zero-dimensional model was proposed for the mass flow rate of a compressor with distorted inlet flow field due to 90° and 180° bent inlet pipe. The non-uniform flow is approximated as two-zone flow field, similar to parallel compressors, with the total pressure deviation between two zones modeled as a function of the flow velocity and pipe geometry. For each flow zone, the corresponding mass flow rate is estimated by approximating each sub-compressor as an adiabatic nozzle, where the fluid is driven by external work delivered by a compressor wheel governed by Euler’s turbomachinery equation. By including turbomachinery physics and compressor geometry information into the modeling, the model achieves high fidelity in compressor map interpretation and extrapolation, which is validated in experiments and the three-dimensional computational fluid dynamic simulation.

scholarly journals Investigating the In-Flow Characteristics of Multi-Operation Conditions of Cross-Flow Fan in Air Conditioning Systems

Processes ◽  
2019 ◽  
Vol 7 (12) ◽  
pp. 959
Author(s):  
Weijie Zhang ◽  
Jianping Yuan ◽  
Qiaorui Si ◽  
Yanxia Fu
Keyword(s):  
Pressure Distribution ◽  
Flow Rate ◽  
Total Pressure ◽  
Air Conditioning ◽  
Pressure Pulsation ◽  
Flow Characteristics ◽  
Cross Flow ◽  
Operating Conditions ◽  
Aerodynamic Noise ◽  
Cross Flow Fan

Cross-flow fans are widely used in numerous applications such as low-pressure ventilation, household appliances, laser instruments, and air-conditioning equipment. Cross-flow fans have superior characteristics, including simple structure, small size, stable airflow, high dynamic pressure coefficient, and low noise. In the present study, numerical simulation and experimental research were carried out to study the unique secondary flow and eccentric vortex flow characteristics of the internal flow field in multi-operating conditions. To this end the vorticity and the circumferential pressure distribution in the air duct are obtained based on the performed experiments and the correlation between spectral characteristics of multiple operating conditions and the inflow state is established. The obtained results show that when the area of the airflow passage decreases while the area of the eccentric vortex area gradually increases, then the airflow of the cross-flow fan decreases, the outlet expands, and the flow pattern uniformity reduces. It was found that wakes form in the vicinity of the blade and the tail of the volute tongue, which generate pressure pulsation, and aerodynamic noise. The pressure distribution along the inner circumference shows that the total minimum pressure appears in the eccentric vortex near the volute tongue and the volute returns near the zone. Moreover, it was found that the total pressure near the eccentric vortex is significantly smaller than that of the main flow zone. As the flow rate decreases, the pressure pulsation amplitude of the eccentric vortex region significantly increases, while the static and total pressure pulsation amplitudes are gradually increased. Close to the eccentric vortex on the inner side of the blade in the volute tongue area, total pressure is low, total pressure on the outside of the blade is not affected, and pressure difference between the inner and outer sides is large. When the flow rate of the cross-flow fan is 0.4 Qd, there is no obvious peak at the harmonic frequency of the blade passage frequency. This shows that the aerodynamic noise is caused by the main unstable flow.

Momentum Exchanges and Energy Transfers in Cross Flow Fans

1987 ◽  
Author(s):  
Joseph Mazur ◽  
Trilochan Singh
Keyword(s):  
Experimental Investigation ◽  
Flow Field ◽  
Cross Flow ◽  
Operating Conditions ◽  
Energy Transfers ◽  
Cross Flow Fan

An experimental investigation of the flow in a cross flow fan at three operating conditions is reported. Velocity and pressure maps for the flow field are presented along with a determination of the momentum exchanges and energy transfers between the blading and the flow field regions.

Internal Flow and Noise Investigations About the Cross-Flow Fan With Different Blade Angles

2012 ◽  
Vol 134 (5) ◽  
Author(s):  
Hua Ouyang ◽  
Jie Tian ◽  
You Li ◽  
Zhiming Zheng ◽  
Zhaohui Du
Keyword(s):  
Relative Velocity ◽  
Numerical Solutions ◽  
Cross Flow ◽  
Internal Flow ◽  
Flow Patterns ◽  
Far Field ◽  
Noise Characteristics ◽  
Aerodynamic Performances ◽  
Field Noise ◽  
Cross Flow Fan

The experimental and numerical studies have been carried out to investigate the flow and the noise characteristics of the three impellers with different blade angles in a cross-flow fan (CFF). First, the aerodynamic performances of the fan with these impellers are obtained experimentally, and the averaged flow patterns inside the impellers are measured by the three-hole probe. Second, the far-field noise generated by CFF with different impellers has been measured in a semianechoic chamber under different throttling conditions. Third, the two-dimensional unsteady CFD simulations have been performed by commercial software. The internal flow patterns influenced by the different blade angles have been summarized through the computational results. The accuracy of the calculations is validated by the corresponding experimental ones. The detail analysis has been carried out on the unsteady vortex flow properties of the three impellers, which is considered to be the main factor that influences the aerodynamic and aeroacoustic performance of the CFF. Finally, the relative far field noise generated by different impellers are evaluated by an empirical formula based on the assumption that the total sound pressure levels are proportional to the sixth power law of the relative velocity on the outer and inner circumferences of the impeller. The circumferential distributions of relative velocity are provided from the numerical solutions. The varying trends of predicted results agree well with the actual relative noise of the CFF with three different impellers.

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.

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