161 Study on the flow field of a small axial flow fan in narrow spaces through LDV and PIV : Effect of tip clearance

2014 ◽  
Vol 2014.49 (0) ◽  
pp. 119-120
Author(s):  
Kouta CHIBA ◽  
Ken-ichi FUNAZAKI ◽  
Hideo TANIGUCHI ◽  
Yusuke MAKINO
Keyword(s):  
Flow Field ◽  
Axial Flow ◽  
Tip Clearance ◽  
Axial Flow Fan ◽  
Small Axial Flow Fan

Experimental Investigation of Tip Clearance Flows of an Axial Flow Fan Using PDA

2002 ◽  
Author(s):  
Xiaocheng Zhu ◽  
Wanlai Lin ◽  
Zhaohui Du ◽  
Yan Zhao
Keyword(s):  
Flow Field ◽  
Reverse Flow ◽  
Axial Flow ◽  
Tip Clearance ◽  
Measurement Technology ◽  
Dynamics Modeling ◽  
Tip Leakage Flow ◽  
Axial Flow Fan ◽  
Tip Leakage Vortex ◽  
Tip Leakage

The three-dimensional flow field in the tip region of an isolated axial flow fan rotor with two different tip clearances are investigated using a three-color, dual-beam PDA system (Particle Doppler Anemometer, DANTEC Measurement Technology). The global performance is also obtained, and is compared favorably with CFD (Computational Fluid Dynamics) modeling of this fan flow at a zero tip clearance. The detailed flow field measurements are taken at 15 axial locations upstream, inside and at the exit of the rotor. In the radial direction, 15 measurement locations are arranged from 50% of the blade span to the casing wall, mainly focusing on the tip region from 90% of the blade span location to the casing wall (about 10 measurement locations). The PDA data has provided a quantitative understanding of the flow phenomena in the tip region of the fan rotor. For both tip clearances, it has been observed that the tip leakage flow rolls up into a tip leakage vortex. Due to the rotation of the rotor, this tip leakage vortex moves away from the suction surface of the fan blade. A reverse flow is induced in the main flow passage because of the tip leakage vortex. The depth and extent of the tip leakage vortex grow noticeably with the increase of the tip clearance.

Performance and Flow Field around a Rotor of a Small Axial Flow Fan Used in Narrow Space

2017 ◽  
Vol 2017.70 (0) ◽  
pp. 307
Author(s):  
Kazuki TATEWAKA ◽  
Norimasa SHIOMI ◽  
Yoichi KINOUE ◽  
Toshiaki SETOGUCHI
Keyword(s):  
Flow Field ◽  
Axial Flow ◽  
Axial Flow Fan ◽  
Small Axial Flow Fan ◽  
Narrow Space

The Measurement of Three-Dimensional Flow Field in an Axial Flow Fan Using PDA

2002 ◽  
Author(s):  
Zhaohui Du ◽  
Wanlai Lin ◽  
Xiaocheng Zhu ◽  
Yan Zhao
Keyword(s):  
Flow Field ◽  
Three Dimensional ◽  
Axial Flow ◽  
Flow Fields ◽  
Tip Clearance ◽  
Measurement Technology ◽  
Particle Dynamic ◽  
Axial Flow Fan ◽  
Three Dimensional Flow ◽  
Dimensional Flow

In this paper, a three-color dual-beam PDA (Particle Dynamic Analyzer) system (made by DANTEC Measurement Technology) is used to measure the three-dimensional velocity of an axial flow fan. Due to the geometrical limit of fan rotor, non-orthogonal velocity components are measured first, from which the orthogonal three-dimensional components of the velocity field are computed through transformation equations. The detailed flow fields at 15 axial locations upstream, inside and at the exit of the rotor are measured, respectively. On each cross section perpendicular to the rotating axis, the flow field measurement at 15 different radial locations from 50% of the blade span to the region inside the tip clearance (between the tip blade and the casing wall) are taken. The experimental technique is described, and the three dimensional flow fields (including the tip clearance flow) are presented and analyzed.

Numerical Simulation on Axial Flow Fan Performance with Changing Tip Clearance

2013 ◽  
Vol 732-733 ◽  
pp. 577-580
Author(s):  
Zhou Ye ◽  
Hai Yang Zhao ◽  
Lu Zhang ◽  
Chun Li ◽  
Wei Gao
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Total Pressure ◽  
Great Influence ◽  
Axial Flow ◽  
Tip Clearance ◽  
Axial Flow Fan ◽  
Flow Solver ◽  
Fan Performance ◽  
Relative Value

Taking the relative tip clearance as the variable, we numerically simulated the effect of tip clearance size on the performance of a straight-blade axial flow fan using the 3-D viscous flow solver. The tip clearance is referenced in the relative value. By comparing the flow field corresponding to five different values of the tip clearance 0, 0.5%, 1.0%, 1.5% and 2.0% with other parameters kept constant, we concluded that the changing of the tip clearance has a great influence on the performance of the axial flow fan. Both the efficiency and the total pressure decrease with the increase of the tip clearance.

The Design of a Large Diameter Axial Flow Fan for Air-Cooled Heat Exchanger Applications

2017 ◽  
Author(s):  
Michael B. Wilkinson ◽  
Johan van der Spuy ◽  
Theodor W. von Backström
Keyword(s):  
Flow Field ◽  
Large Diameter ◽  
Axial Flow ◽  
Pressure Rise ◽  
Design Procedure ◽  
Axial Flow Fan ◽  
Disk Model ◽  
Actuator Disk ◽  
Static Efficiency ◽  
Air Cooled Heat Exchanger

An axial flow fan design methodology is developed to design large diameter, low pressure rise, rotor-only fans for large air-cooled heat exchangers. The procedure aims to design highly efficient axial flow fans that perform well when subjected to off design conditions commonly encountered in air-cooled heat exchangers. The procedure makes use of several optimisation steps in order to achieve this. These steps include optimising the hub-tip ratio, vortex distribution, blading and aerofoil camber distributions in order to attain maximum total-to-static efficiency at the design point. In order to validate the design procedure a 24 ft, 8 bladed axial flow fan is designed to the specifications required for an air-cooled heat exchanger for a concentrated solar power (CSP) plant. The designed fan is numerically evaluated using both a modified version of the actuator disk model and a three dimensional periodic fan blade model. The results of these CFD simulations are used to evaluate the design procedure by comparing the fan performance characteristic data to the design specification and values calculated by the design code. The flow field directly down stream of the fan is also analysed in order to evaluate how closely the numerically predicted flow field matches the designed flow field, as well as determine whether the assumptions made in the design procedure are reasonable. The fan is found to meet the required pressure rise, however the fan total-to-static efficiency is found to be lower than estimated during the design process. The actuator disk model is found to under estimate the power consumption of the fan, however the actuator disk model does provide a reasonable estimate of the exit flow conditions as well as the total-to-static pressure characteristic of the fan.

Effects of Stator Wakes and Spanwise Nonuniform Inlet Conditions on the Rotor Flow of an Axial Turbine Stage

1993 ◽  
Vol 115 (1) ◽  
pp. 128-136 ◽  
Author(s):  
J. Zeschky ◽  
H. E. Gallus
Keyword(s):  
Flow Field ◽  
Three Dimensional ◽  
Axial Flow ◽  
Tip Clearance ◽  
Hot Wire ◽  
Turbine Stage ◽  
Static Pressure Distribution ◽  
Inlet Conditions ◽  
Experimental Values ◽  
Rotor Flow

Detailed measurements have been performed in a subsonic, axial-flow turbine stage to investigate the structure of the secondary flow field and the loss generation. The data include the static pressure distribution on the rotor blade passage surfaces and radial-circumferential measurements of the rotor exit flow field using three-dimensional hot-wire and pneumatic probes. The flow field at the rotor outlet is derived from unsteady hot-wire measurements with high temporal and spatial resolution. The paper presents the formation of the tip clearance vortex and the passage vortices, which are strongly influenced by the spanwise nonuniform stator outlet flow. Taking the experimental values for the unsteady flow velocities and turbulence properties, the effect of the periodic stator wakes on the rotor flow is discussed.

Effect of the uneven circumferential blade space on the performance of small axial flow fan

2016 ◽  
Vol 25 (6) ◽  
pp. 492-500
Author(s):  
Yang Liu ◽  
Zhe Lin ◽  
Peifeng Lin ◽  
Yingzi Jin ◽  
Toshiaki Setoguchi ◽  
...  
Keyword(s):  
Axial Flow ◽  
Axial Flow Fan ◽  
Small Axial Flow Fan
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