The Cavermod Device: Hydrodynamic Aspects and Erosion Tests

1999 ◽  
Vol 121 (2) ◽  
pp. 305-311 ◽  
Author(s):  
E. G. Filali ◽  
J. M. Michel
Keyword(s):  
Rotation Rate ◽  
Cavitation Erosion ◽  
Companion Paper ◽  
Core Collapse ◽  
Pure Aluminium ◽  
Force Measurements ◽  
Test Device ◽  
Erosion Model ◽  
Erosion Test

The Cavermod (CAVitation ERosion MODel) is an erosion test device first described by Dominguez-Cortazar et al. (1992, 1997). Recently, it was modified in two steps: first by increasing its maximum rotation rate (from 4500 to 8000 rpm) and second by shortening its vapor core (from 156 to 66 mm). This paper plans to present the main results which are obtained in both configurations (long and short vortex) and for “slow” or “rapid” regime of rotation. They mainly concern 1. the hydrodynamic aspects of the vapor core collapse, as deduced from observation of rapid films (evolution of the vortex length, collapse, velocity), 2. the erosion patterns produced on metallic targets such as pure aluminium and copper. A second companion paper will present the results of force measurements in both configuration and an attempt to estimate the local erosive pressures.

Analysis of the External Conditions Affecting on the Cavitation Resistance of a Steel

2019 ◽  
Vol 946 ◽  
pp. 31-36
Author(s):  
Hussam L. Alwan ◽  
N. Lezhnin ◽  
Yury Korobov
Keyword(s):  
Surface Resistance ◽  
Cavitation Erosion ◽  
Medium Carbon Steel ◽  
Cavitation Resistance ◽  
Nacl Solution ◽  
Medium Carbon ◽  
Test Conditions ◽  
External Conditions ◽  
Erosion Test ◽  
Testing Liquid

The aim of this study is to analyze the effect of cavitation erosion test conditions on the surface resistance of medium carbon steel. The ultrasonic vibratory specimen system was used to perform the experiments under the laboratory conditions. The vibratory frequency and the displacement amplitude were 20 kHz and 20 μm, respectively. In design of experiments, four various cavitation behaviors have been studied based on four cavitation test conditions corresponding to those behaviors. These conditions can be summarized as follows: (1) the usage of water as a testing liquid; (2) replacement the water with 3.5% NaCl solution; (3) applying a certain voltage to cause a combined electrochemical action working simultaneously with the water; and (4) applying the same voltage by using the 3.5% NaCl solution instead of water. The obtained results showed that the mass loss differs by test modes applied.

The Cavermod Device: Force Measurements

1999 ◽  
Vol 121 (2) ◽  
pp. 312-317 ◽  
Author(s):  
E. G. Filali ◽  
J. M. Michel ◽  
S. Hattori ◽  
S. Fujikawa
Keyword(s):  
Solid Wall ◽  
Axial Direction ◽  
Companion Paper ◽  
Point Of View ◽  
Pvdf Film ◽  
Force Measurements ◽  
Hard Materials ◽  
Force Signal ◽  
Ceramic Transducer ◽  
Film Transducer

The Cavermod device, as described in the companion paper (Filali et al., 1999), allows us to produce the axial collapse of a cavitating vortex at high velocities. From a global point of view, we can consider that it produces a high momentum in the axial direction. Large forces, concentrated on a small area and able to produce erosion pits on hard materials, result from the sudden momentum stopping against a solid wall. In this paper, the results of the forces measurements are given. Four different measurements devices are used to analyze the Cavermod performance in both cases of long and short vortex: dislocations in MgO (Magnesium Oxide) single crystal, two special piezoelectric ceramic transducers and a PVDF film transducer. Special attention is given to the PVDF film response which is found twice the response of other devices. In addition, an attempt is made to interpret the temporal force signal given by a ceramic transducer in terms of local erosive pressure.

The Cavitation Behavior of Fe-Cr-C-Si-Ni Alloys

2006 ◽  
Vol 510-511 ◽  
pp. 274-277
Author(s):  
Ji Hui Kim ◽  
Kwang Su Na ◽  
Seon Jin Kim
Keyword(s):  
Work Hardening ◽  
Cavitation Erosion ◽  
Erosion Resistance ◽  
Hardfacing Alloy ◽  
Ni Alloys ◽  
Ni Addition ◽  
Work Hardening Rate ◽  
Erosion Test ◽  
Cavitation Behavior ◽  
Cavitation Erosion Resistance

The cavitation erosion behavior of Fe-Cr-C-Si-xNi (x = 1, 2 and 3 wt.%) alloys were investigated for 50 hours using a 20 kHz vibratory cavitation erosion test equipment. 1 wt.% Ni added Fe-based hardfacing alloy showed excellent cavitation erosion resistance, comparable to the stellite 6. Above 1 wt.% Ni, however, the erosion resistance deteriorated quickly. It is conjectured that Ni addition above 1 wt.%, which has been shown to increase the stacking fault energy (SFE), resulted in reduction of the work hardening rate during the erosion test. Therefore, the enhanced cavitation erosion resistance of the 1 wt.% Ni alloy over the 2 and 3 wt.% Ni alloys could be explained in terms of the SFE, Ms temperature and work hardening.

scholarly journals Cavitation Erosion – Phenomenon and Test Rigs

2018 ◽  
Vol 18 (2) ◽  
pp. 15-26 ◽  
Author(s):  
A. K. Krella ◽  
D. E. Zakrzewska
Keyword(s):  
Cavitation Erosion ◽  
Erosion Resistance ◽  
Test Design ◽  
Test Device ◽  
Test Conditions ◽  
Cavitation Erosion Resistance ◽  
Cavitating Jet

AbstractThe cavitation and cavitation erosion phenomenon have been shortly presented. The main four types of test rigs to investigate the cavitation erosion resistance have been shown. Each type of test design is described and an example of a design is shown. A special attention has been payed to the designs described in the International ASTM Standards: a vibratory design and a cavitating jet cell. There was shown that the design of a test device and the test conditions affect the resistance to cavitation erosion of a material.

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