705 Numerical Analysis of Complex Vortical Flow Phenomena in Transonic Internal Flow Fields

2001 ◽  
Vol 2001 (0) ◽  
pp. 97
Author(s):  
Masato FURUKAWA ◽  
Kazutoyo YAMADA ◽  
Aritoshi IMAZATO ◽  
Masahiro INOUE
Keyword(s):  
Numerical Analysis ◽  
Internal Flow ◽  
Flow Fields ◽  
Vortical Flow ◽  
Flow Phenomena

Internal Flow Condition of Fluid Food Pump Using Semi-Open Impeller

2015 ◽  
Author(s):  
Toru Shigemitsu ◽  
Hirotaka Shinohara ◽  
Takumi Matsubara ◽  
Junichiro Fukutomi
Keyword(s):  
Numerical Analysis ◽  
Flow Condition ◽  
Design Method ◽  
Internal Flow ◽  
Axial Position ◽  
Flow Conditions ◽  
Flow Passage ◽  
Flow Phenomena ◽  
Turbo Pump

Fluid machineries for fluid food have been used in wide variety of field i.e. transportation, filling, and improvement of quality of fluid food. Although, flow conditions of these are quite complicated because fluid food is different from water. Therefore, a design method based on the internal flow conditions is not conducted. In this research, turbo-pump having small number of blade was used to decrease shear loss and keep wide flow passage. The flow phenomena were not clarified in detail, although, it was found that internal flow condition was complex in the test pump in previous studies. In order to investigate the complex internal flow condition, the unsteady numerical analysis using low viscous fluid was conducted. In this paper, the internal flow conditions at each axial position of the centrifugal pump having semi-open impeller were investigated by the numerical analysis results. In addition to that, the influence of the internal flow conditions on its head was clarified.

Magnetophoresis Effects on the Flow Characteristics of Oil-Based Ferrofluids in Rectangular Enclosures

2015 ◽  
Vol 15 (10) ◽  
pp. 7451-7456
Author(s):  
Hyeon-Seok Seo ◽  
Jin-Hyo Boo ◽  
Youn-Jea Kim
Keyword(s):  
Magnetic Fields ◽  
Permanent Magnet ◽  
Flow Characteristics ◽  
Flow Fields ◽  
Working Fluid ◽  
Magnetic Flux Density ◽  
Magnetic Field Direction ◽  
Analysis Model ◽  
Rectangular Enclosure ◽  
Flow Phenomena

This study numerically investigated the flow characteristics in a rectangular enclosure filled with oil-based ferrofluid (EFH-1, Ferrotec.) under the influence of external magnetic fields. The rectangular enclosure contained obstacles with different shapes, such as a rectangle and a triangle mounted on the top and bottom wall surfaces. In order to generate external magnetic fields, a permanent magnet was located in the lower part of the rectangular enclosure, and its direction was selected to be either horizontal or vertical. Our results showed that the ferrofluid flow fields were affected by the applied external magnetic field direction and eddy flow phenomena in the working fluid were generated in the vicinity of high magnetic flux density distributions, such as at the edge of the permanent magnet. It was also confirmed that the magnetophoretic force distributions in the analysis model played a significant role in the development of the ferrofluid flow fields.

Visualization of Internal Flow Field of Propeller Fan

2017 ◽  
Author(s):  
Takaya Onishi ◽  
H. Sato ◽  
M. Hayakawa ◽  
Y. Kawata
Keyword(s):  
Flow Field ◽  
High Performance ◽  
Laser Light ◽  
Internal Flow ◽  
Light Sheet ◽  
Tip Vortex ◽  
Laser Light Sheet ◽  
Blade Surface ◽  
Similar Tendency ◽  
Flow Phenomena

Propeller fans are required not only to have high performance but also to be extremely quiet. The internal flow field of ventilation propeller fans is even more complicated because they usually have a very peculiar configuration with protruding blades upstream. Thus, many kinds of internal vortices yield which cause noise and their cause and countermeasures are needed to be clarified. The purposes of this paper are to visualize the internal flow of the propeller fan from the static and rotating frame of reference. The internal flow visualization measured from the static frame gives approximately the scale of the tip vortex. The visualization from the rotating coordinate system yields a better understanding of the flow phenomena occurring at the specific blade. The experiment is implemented by using a small camera mounted on the shaft of the fan and rotated it to capture the behavior of the vortices using a laser light sheet to irradiate the blade surface. Hence, the flow field of the specific blade could be understood to some extent. The visualized results are compared with the CFD results and these results show a similar tendency about the generation point and developing process of the tip vortex. In addition, it is found that the noise measurement result is relevant to the effect of tip vortex from the visualization result.

scholarly journals Internal Flow of a High Specific-Speed Diagonal-Flow Fan (Rotor Outlet Flow Fields with Rotating Stall)

2003 ◽  
Vol 9 (5) ◽  
pp. 337-344 ◽  
Author(s):  
Norimasa Shiomi ◽  
Wen-Xin Cai ◽  
Akio Muraoka ◽  
Kenji Kaneko ◽  
Toshiaki Setoguchi
Keyword(s):  
Internal Flow ◽  
Flow Fields ◽  
Rotating Stall ◽  
Outlet Flow ◽  
Specific Speed

scholarly journals Numerical Analysis of a Model Pump-turbine Internal Flow Behavior in Pump Hump District

2014 ◽  
Vol 22 (3) ◽  
pp. 032040 ◽  
Author(s):  
Yao Yangyang ◽  
Xiao Yexiang ◽  
Zhu Wei ◽  
Zhai Liming ◽  
An Soo Hwang ◽  
...  
Keyword(s):  
Numerical Analysis ◽  
Flow Behavior ◽  
Internal Flow ◽  
Pump Turbine

Effect of Wakes and Secondary Flow on Re-attachment of Turbine Exit Annular Diffuser Flow

2009 ◽  
Vol 131 (4) ◽  
Author(s):  
David Kluß ◽  
Horst Stoff ◽  
Alexander Wiedermann
Keyword(s):  
New York ◽  
Secondary Flow ◽  
Internal Flow ◽  
Free Jet ◽  
Diffuser Flow ◽  
Ansys Cfx ◽  
Flow Phenomena ◽  
Annular Diffuser ◽  
Commercial Solver ◽  
Turbine Exhaust

In this paper numerical results of wake and secondary flow interaction in diffuser flow fields are discussed. The wake and secondary flow are generated by a rotating wheel equipped with 30 cylindrical spokes with a diameter of 10 mm as a first approach to the turbine exit flow environment. The apex angle of the diffuser is chosen such that the flow is strongly separated according to the well-known performance charts of Sovran and Klomp (1967, “Experimentally Determined Optimum Geometries for Rectilinear Diffusers With Rectangular, Conical or Annular Cross-Section,” in Fluid Mechanics of Internal Flow, Elsevier, New York, pp. 272–319). This configuration has been tested in an experimental test rig at the Leibniz University Hannover (Sieker and Seume 2007, “Influence of Rotating Wakes on Separation in Turbine Exhaust Diffusers,” Paper No. ISAIF8-54). According to these experiments, the flow in the diffuser separates as free jet for low rotational speeds of the spoke-wheel, as expected by theory. However, if the 30 spokes of the upstream wheel rotate beyond the value of 500 rpm the measurements indicate that the flow remains attached to the outer diffuser wall. It will be shown by the present numerical analysis with the commercial solver ANSYS CFX-10.0 that only an unsteady approach using the elaborate scale adaptive simulation with the shear stress transport turbulence model is capable of predicting the stabilizing effect of the rotating wheel to the diffuser flow at larger rotational speeds. The favorable comparison with the experimental data suggests that the mixing effect of wakes and secondary flow pattern is responsible for the reattachment. As a result of our studies, it can be stated that the considerably higher numerical costs associated with unsteady calculations must be accepted in order to increase the understanding of the physical flow phenomena in turbine exit flow and its interaction with the downstream diffuser.

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