[PDF] Standard Test Method For Cavitation Erosion Using Vibratory Apparatus eBook

Author : Georges L. Chahine
Publisher :
Page : 35 pages
File Size : 31,16 MB
Release : 2018
Category : Cavitation erosion
ISBN :

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Predicting cavitation erosion under full-scale operating conditions is difficult and relies on laboratory testing using accelerated methods such as ASTM G32-09, Standard Test Method for Cavitation Erosion Using Vibratory Apparatus, and ASTM G134-95, Standard Test Method for Erosion of Solid Materials by a Cavitating Liquid Jet. The main difficulty is that full-scale cavitation intensity is often unknown, and correlating cavitation field characteristics of the accelerated method and the full scale is not obvious. The problem is more acute for compliant polymeric coatings, used for protection or repair of parts subject to cavitation. Extensive testing of such materials shows that, unlike metallic surfaces, they are highly resistant to low-intensity cavitation but fail catastrophically when the intensity exceeds a certain threshold. Such behavior creates the risk of accepting a candidate coating for its resistance to cavitation if the coating was tested at a low cavitation intensity not representative of the application field conditions. This highlights the need to conduct tests with a range of cavitation intensities rather than a single intensity. This article uses results from extensive tests under various forms of cavitation to propose a generalized definition of cavitation intensity. It then presents data on the response of both metals and polymeric coatings to various levels of accelerated cavitation. A new method to test the coatings at varying cavitation intensities is then presented. Such tests provide maps of material resistance to different levels of cavitation and are helpful to make an informed decision. The tests also show that during cavitation exposure, the coatings are subjected not only to mechanical stress but also to significant heating, which dynamically modifies their properties during the exposure. Temperature rise in the coating when exposed to cavitation is directly connected to the cavitation intensity to which it is exposed, and this interaction needs to be considered.

Author : Spencer Court
Publisher :
Page : 14 pages
File Size : 20,4 MB
Release : 2018
Category : Cavitation erosion
ISBN :

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Cavitation erosion has to be taken into consideration during material selection in many industrial sectors, e.g., offshore, marine, and oil and gas, in which components operate under severe working conditions. The cavitation erosion equipment, located at the University of Southampton, uses a vibratory apparatus to compare, rank, and characterize the cavitation erosion performance of materials. This article highlights some of the results obtained from industrial research (consultancy) work employing a Hielscher UIP1000hd 20 kHz ultrasonic transducer (Hielscher Ultrasonics GmbH, Teltow, Germany). The transducer is attached to a titanium horn to induce the formation and collapse of cavities in a liquid, creating erosion (material loss) of the specimen undergoing testing. The results from erosion cavitation testing (in accordance with ASTM G32-16, Standard Test Method for Cavitation Erosion Using Vibratory Apparatus (Superseded)) of two commercially available steels are presented herein and are shown to have less resistance to cavitation when compared to polyether(ether ketone), ceramic, and carbide materials. These materials are presented, along with Nickel 200, which was used to normalize the results. A plot of cumulative erosion versus exposure time was determined by periodic interruption of the test.

Author : Ki-Han Kim
Publisher : Springer
Page : 407 pages
File Size : 33,21 MB
Release : 2014-07-08
Category : Technology & Engineering
ISBN : 9401785392

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This book provides a comprehensive treatment of the cavitation erosion phenomenon and state-of-the-art research in the field. It is divided into two parts. Part 1 consists of seven chapters, offering a wide range of computational and experimental approaches to cavitation erosion. It includes a general introduction to cavitation and cavitation erosion a detailed description of facilities and measurement techniques commonly used in cavitation erosion studies, an extensive presentation of various stages of cavitation damage (including incubation and mass loss) and insights into the contribution of computational methods to the analysis of both fluid and material behavior. The proposed approach is based on a detailed description of impact loads generated by collapsing cavitation bubbles and a physical analysis of the material response to these loads. Part 2 is devoted to a selection of nine papers presented at the International Workshop on Advanced Experimental and Numerical Techniques for Cavitation Erosion Prediction (Grenoble, France, 1-2 March 2011) representing the forefront of research on cavitation erosion. Innovative numerical and experimental investigations illustrate the most advanced breakthroughs in cavitation erosion research.

Author : Y. Meged
Publisher :
Page : 30 pages
File Size : 41,14 MB
Release : 2014
Category : Cavitation erosion
ISBN :

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In the framework of the International Cavitation Erosion Test (ICET), 119 vibratory cavitation erosion tests were performed. Seventy of these tests were with vibrating specimens (VRV), and forty-nine with stationary specimens (VRS). From these tests, twenty tests of each type were chosen for this study. VRV tests are covered by ASTM G32-10, whereas for VRS, no standard has yet been published. This anomaly stems from the difficulties encountered in both testing and evaluating of VRS tests. All forty cavitation erosion-time curves were analyzed by the Transient Response for Erosion (TRE) method. For each curve, all three parameters were determined, namely: time lag (TL), time constant (?), and the asymptotic value of the mean depth of erosion, mean depth of erosion (MDE) MDEMAX. These parameters were further applied to calculate the scatter of test results as obtained from various specimens tested under identical conditions. This method enables the determination of the absolute and relative scatter values at any time value along the test. Finally, several guidelines are specified for preparation of a future VRS standard.