Experimental and numerical investigation of binary coalescence: Liquid bridge building and internal flow fields

2012 ◽  
Vol 24 (6) ◽  
pp. 062108 ◽  
Author(s):  
R. T. Eiswirth ◽  
H.-J. Bart ◽  
A. A. Ganguli ◽  
E. Y. Kenig
Keyword(s):  
Numerical Investigation ◽  
Liquid Bridge ◽  
Internal Flow ◽  
Flow Fields ◽  
Bridge Building

Turbulence Model Influence on Numerical Investigation of Transonic Axial Compressor Rotor

2011 ◽  
Vol 308-310 ◽  
pp. 1519-1522
Author(s):  
Fang Xie ◽  
Chang Jiang Liu ◽  
You Jun Wang
Keyword(s):  
Experimental Data ◽  
Numerical Investigation ◽  
Turbulence Model ◽  
Characteristic Curve ◽  
Axial Compressor ◽  
Internal Flow ◽  
Turbulent Model ◽  
Compressor Rotor ◽  
Transonic Axial Compressor ◽  
Point Forecast

Numerical method using HI and HOH meshing combined B - L turbulent model and S - A turbulent model separately based on the Rotor 37 compressor Rotor was applied to the steady flow. results on pressure characteristic curve, stall point forecast etc were compared with related experimental data. This paper discussed calculation precision influenced by the turbulence model and numerical computation grid. This numerical investigation was basis for subsequent compressor internal flow field study.

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

Numerical Investigation of Internal Flow in a Salient Pole Synchronous Generator

2020 ◽  
Vol 2020 (0) ◽  
pp. 17B12
Author(s):  
Takuma MUTOH ◽  
Akira OZAWA ◽  
Teppei IKUTA ◽  
Takumi ITO ◽  
Nobumichi FUJISAWA ◽  
...  
Keyword(s):  
Numerical Investigation ◽  
Internal Flow ◽  
Synchronous Generator ◽  
Salient Pole

Transient characteristics of internal flow fields of mixed-flow pump with different tip clearances under stall condition

2020 ◽  
pp. 095765092096225
Author(s):  
Leilei Ji ◽  
Wei Li ◽  
Weidong Shi ◽  
Ramesh Agarwal
Keyword(s):  
Swirling Flow ◽  
Internal Flow ◽  
Flow Fields ◽  
Design Flow ◽  
Tip Clearance ◽  
Tip Leakage Flow ◽  
Mixed Flow ◽  
Transient Characteristics ◽  
Initial Starting ◽  
Flow Pump

This paper investigates the influence of different tip clearances on the transient characteristics of mixed-flow pump under stall condition. The instantaneous internal flow fields of mixed-flow pump with four tip clearances (0.2 mm, 0.5 mm, 0.8 mm and 1.1 mm) are explored by conducting unsteady time accurate simulations. Reynolds-averaged Navier-Stokes (RANS) equations are employed in the simulations and the results of computations are compared with experimental data. The results show that the pump head decreases by 22.1% and the pump efficiency drops by 13.9% at design flow condition when the impeller tip clearance increases from 0.2 mm to 1.1 mm. The swirling flow occurs in the inlet pipe of the mixed-flow pump with different tip clearances under stall condition, and the initial starting point of the swirling flow gets further away from the impeller inlet with increase in tip clearance because of increase in circumferential velocity and change in momentum of the tip leakage flow (TLF). The high turbulent eddy dissipation (TED) regions in the flow are attributed to the TLF, swirling flow, back flow and stall vortex, and their intensity are affected by the change in tip clearance. The oscillating trend of time domain distribution of TED enhances first and then decreases with increase in tip clearance and it exhibits a propagation feature under the effect of stall vortex, while most of the energy in the frequency domain remains concentrated in the low frequency part under stall condition.

Investigation of Pre-Stall Behavior in an Axial Compressor Rotor—Part II: Flow Mechanism of Spike Emergence

2012 ◽  
Vol 134 (5) ◽  
Author(s):  
Yanhui Wu ◽  
Qingpeng Li ◽  
Jiangtao Tian ◽  
Wuli Chu
Keyword(s):  
Axial Flow ◽  
Internal Flow ◽  
Propagation Speed ◽  
Suction Side ◽  
Flow Fields ◽  
Development Stage ◽  
Tip Clearance ◽  
The Self ◽  
Flow Mechanism ◽  
Compressor Rotor

To investigate the pre-stall behavior of an axial flow compressor rotor, which was experimentally observed with spike-type stall inception, systematic experimental and whole-passage simulations were laid out to analyze the internal flow fields in the test rotor. In this part, emphases were put on the analyses of the flow fields of whole-passage simulation, which finally diverged, and the objective was to uncover the flow mechanism of short length scale disturbance (or spike) emergence. The numerical result demonstrated that the test rotor was of spike-type stall initiation. The numerical probes, arranged ahead of the rotor to monitor the static pressure variation, showed that there first appear two pips on the curves. After one rotor revolution, there was only one pip left, spreading at about 33.3% rotor speed. This propagation speed was almost the same as that of the spike observed in experiments. The further analysis of the flow field revealed a concentrated blockage sector on the flow annuls ahead of rotor developed gradually with the self-adjustment of flow fields. The two pins on monitoring curves corresponded to two local blockage regions in near-tip passages, and were designated as B1 and B2, respectively. The correlation between the tip secondary vortices (TSVs) in the preceding and native passages was the flow mechanism for propagation of B2 and B1, thereby leading to their spread speed approximate to the active period of the TSV in one passage. Furthermore, the self-sustained unsteady cycle of TSVs was the underlying flow mechanism for the occurrence of the so-called “tip clearance spillage flow” and “tip clearance backflow.” Because B2 was the tip-front of the blockage sector, TSVs associated with its propagation became stronger and stronger, so that the “tip clearance backflow” induced by it was capable of spilling into the next passage below the blade tip. This phenomenon was regarded as the threshold event where B2 started to evolve into a spike. The distinctive flow feature during the development stage of the spike was the occurrence of a separation focus on the suction side in the affected passages, which changed the self-sustained unsteady cycle of the TSV substantially. A three-dimensional vortex originating from this focus led to a drastic increase in the strength of the TSV, which, in turn, led to a rapid increase in the “tip clearance backflow” induced by the TSV and the radial extent of spillage flow.

Experimental Investigation of the Full Flow Field in a Molten Salt Pump by Particle Image Velocimetry

2015 ◽  
Vol 137 (10) ◽  
Author(s):  
Chunlei Shao ◽  
Jianfeng Zhou ◽  
Boqin Gu ◽  
Wenjie Cheng
Keyword(s):  
Particle Image Velocimetry ◽  
Molten Salt ◽  
Particle Image ◽  
Weighted Average ◽  
Internal Flow ◽  
Flow Fields ◽  
Flow Angle ◽  
Divergent Flow ◽  
Image Velocimetry ◽  
Distribution Uniformity

Particle image velocimetry (PIV) technology was used to study steady and unsteady internal flow fields in a molten salt pump under both internal and external synchronization modes. The velocity fields in the suction chamber, impeller passage and volute were analyzed at different flow rates. The velocity distribution uniformity, velocity weighted average divergent flow angle, and circumferential component of absolute velocity were calculated on the basis of the obtained flow fields. The research is meaningful to the development of molten salt pumps, and the experimental method serves as a reference to similar rotating fluid machinery.

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