COBEM99

SR28 Tribologia

Title:

CORRELATION BETWEEN COLLAPSE PRESSURE AND MATERIAL LOSS IN CAVITATION EROSION

Summary :

ABSTRACT: CAVITATION OCCURS IN HYDRAULIC MACHINERY DUE TO THE REPEATED GROWTH AND COLLAPSE OF BUBBLES, WHICH CAN ARISE DURING THE FLOW OF A LIQUID. THE STRESS GENERATED BY THIS COLLAPSE IS HIGH ENOUGH TO CAUSE A SEVERE WEAR IN THE NEARBY SURFACES. UNTIL TODAY, IT IS IMPOSSIBLE TO PREDICT THE SERVICE LIFE OF A COMPONENT SUBJECTED TO CAVITATION. THE REASON FOR THIS LACK OF PREDICTABILITY IS THAT THE MECHANISMS INVOLVED IN MATERIAL LOSS ARE NOT COMPLETELY UNDERSTOOD. DURING THE LAST YEARS, THE INTEREST IN THE USE OF SENSORS TO STUDY CAVITATION EROSION HAS INCREASED. THE AIM OF THIS PAPER IS TO INVESTIGATE THE MECHANISMS OF CAVITATION EROSION BY MEANS OF A PIEZOELECTRIC POLYMER FILM SENSOR (PVDF). THE SENSOR WAS POSITIONED NEAR A CAVITATION ZONE CREATED BY A VIBRATORY DEVICE. OVER THAT SENSOR WAS PLACED AN ALUMINUM PLATE. THIS EXPERIMENTAL ARRANGEMENT PERMITTED TO ACQUIRE DATA ABOUT THE BEHAVIOR OF THIS MATERIAL DURING THE TEST. THE RESULTS SHOWED THAT THERE IS GOOD CORRELATION BETWEEN THE INFORMATION FROM THE SIGNAL AND THE MASS LOSS OF THE SAMPLE. TESTS WERE PERFORMED AT DIFFERENT AMPLITUDES IN ORDER TO VERIFY THE INFLUENCE OF THIS PARAMETER IN THE MASS LOSS OF THE SAMPLE. KEY WORDS: CAVITATION, PVDF, SENSOR, SIGNAL ANALYSIS

Author :

Castanho, Flávio 0
Cuppari, Marcio G. D Vernieri
Oraggio, Alex Fabiano
Padovese, Linilson Rodrigues

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