Validation of numerical simulations of cavitating flow in hydraulic system using an optoelectronic system

2015 ◽  
Author(s):  
A. Niedzwiedzka ◽  
S. Lipinski ◽  
W. Sobieski
Keyword(s):  
Numerical Simulations ◽  
Hydraulic System ◽  
Cavitating Flow ◽  
Optoelectronic System

scholarly journals On the Scaling of Bubble Cluster Collapse in Cloud Cavitating Flow Around a Slender Projectile

2015 ◽  
Author(s):  
Yiwei Wang ◽  
Chenguang Huang ◽  
Xiaocui Wu
Keyword(s):  
Phase Change ◽  
Numerical Simulations ◽  
Scaling Law ◽  
Cavitating Flow ◽  
Cavitation Model ◽  
Bubble Cluster ◽  
Collapse Pressure ◽  
Variation Range ◽  
Main Factors ◽  
Similarity Law

The scaling law of bubble cluster collapse in cloud cavitating flow around a slender projectile is investigated in the present paper. The influence of compressibility is mainly discussed. Firstly the governing parameters are obtained by dimensional analysis, and the numerical method is established in order to verify the similarity law and obtain the influence of parameters based on a mixture approach with Singhal cavitation model. Moreover, the similarity law is validated by numerical simulations. Two main factors of compressibility of mixture fluid, including compressibility of non-condensable gas and phase change, are studied, respectively. Results indicated that the phase change has little influence on both flowing and collapse pressure. In the condition that the variation range of the mixture compressibility is small, the compressibility of non-condensable gas has notable impact the local collapse pressure peaks, however the macroscopic flow pattern does not change.

Numerical and Experimental Investigations of the Cavitating Flow in a Centrifugal Pump Impeller

2002 ◽  
Author(s):  
Moritz Frobenius ◽  
Rudolf Schilling ◽  
Jens Friedrichs ◽  
Gu¨nter Kosyna
Keyword(s):  
Numerical Simulations ◽  
Centrifugal Pump ◽  
Bubble Dynamics ◽  
Cavitating Flow ◽  
Experimental Investigations ◽  
Pump Impeller ◽  
Pump Head ◽  
Flow Through ◽  
Technical University ◽  
Centrifugal Pump Impeller

This paper presents numerical simulations and experimental investigations of the cavitating flow through a centrifugal pump impeller of low specific speed. The experimental research was carried out at the Pfleiderer-Institute of the Technical University of Braunschweig, while the numerical simulations were performed at the Institute for Hydraulic Machinery and Plants at the Technical University of Munich (LHM). The cavitation model used is based on bubble dynamics and is able to describe the complicated and transient growth and collapse of the cavitation bubbles. The model has been implemented in the 3D CFD-code CNS3D developed at the LHM. The CNS3D-code has been applied to simulate the cavitating flow through a centrifugal pump impeller. The computed pump head, incipient NPSH and three-percent head drop are compared to the experimental data. Also the pressure distributions measured on the blades are compared with the computed ones. Finally, the numerically investigated void fraction distributions are shown in comparison with pictures of the cavitation zones on the blade.

Hydraulic Control of Speed and Position of a Pneumatic Actuator

2015 ◽  
Vol 772 ◽  
pp. 334-338
Author(s):  
Mihai Avram ◽  
Constantin Bucşan ◽  
Despina Duminică ◽  
Dana Rizescu ◽  
Daniel Besnea
Keyword(s):  
Mathematical Model ◽  
Numerical Simulations ◽  
Hydraulic System ◽  
Experimental Results ◽  
Pneumatic Actuator ◽  
Hydraulic Control ◽  
Hydraulic Circuit

The paper presents an original pneumo-hydraulic system that controls the speed and the position of the actuated load by using a hydraulic circuit containing a hydraulic proportional throttle. A mathematical model of the solution is developed and numerical simulations are performed. The experimental results obtained on the built model confirm the theoretical ones.

scholarly journals Vibrations of water hydraulic systems – an experimental approach

2019 ◽  
Vol 85 ◽  
pp. 06006
Author(s):  
Andrei Dragomirescu ◽  
Carmen-Anca Safta ◽  
Nicolae Orăşanu ◽  
Ioan Magheţi ◽  
Lucian Mândrea
Keyword(s):  
Experimental Study ◽  
High Frequency ◽  
Hydraulic System ◽  
Experimental Approach ◽  
Cavitating Flow ◽  
Hydraulic Systems ◽  
Butterfly Valve ◽  
Flow Rates ◽  
Drive Motor ◽  
Water Hydraulic

This paper presents an experimental study of the vibrations induced both by cavitating and by non-cavitating flow in a hydraulic installation that comprises the main elements of a water hydraulic system. The cavitation was triggered by progressively closing a butterfly valve. The vibrations were measured on the pump, on the bearings housing, on the pump drive motor, and at nine measurement points located upstream and downstream of the main elements of the installation. The measurements were carried out at different flow rates obtained at different openings of the butterfly valve. The results suggest that the phenomena that take place inside the pump and inside the bearings cause vibrations having frequencies of up to 10 kHz. The results also indicate that the cavitation that occurs at the butterfly valve causes vibrations of high frequency, above 3 kHz, that have a distinct peak at about 18 kHz. These results could be useful in establishing proper maintenance plans for hydraulic installations.

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