Interesting Facts (and Myths) about Cavitation - a PDH Online Course for Engineers and Surveyors

Interesting Facts (and Myths) about Cavitation

Course Outline

The term cavitation describes the phenomenon of liquid-to-gas and gas-to-liquid phase changes that occur when the local fluid pressure in areas of accelerated flow drops below the vapor pressure of the fluid. The gas-to-liquid phase change produces extremely high local pressures as vapor cavities implode. Damage, erosion, and even corrosion occur when implosions occur near boundaries of solid flow surfaces. Collapsing cavitation bubbles cause noise, vibration, and elevated temperature. Erosion damage leads to drops in efficiency and ultimately major damage to equipment. Significant shortened equipment service life results when cavitation occurs.

This course provides micro and macro, theoretical as well as practical viewpoints about the process of cavitation. It will provide you with some interesting facts and some widely accepted, but inaccurate beliefs regarding cavitation.

This course includes a multiple choice quiz at the end, which is designed to enhance the understanding of the course materials.

Learning Objective

At the conclusion of this course, you will learn the:

Concept of cavitation and how it was discovered;
Difference in cavitation, boiling, and flashing;
Theory of cavitation;
History of cavitation research;
Why, where, and when of cavitation;
Types of cavitation;
Damage that can be produced from cavitation;
Phenomena of bubble instability and asymmetry;
Concepts of reentrant micro jet and remnant cloud shock;
Process of cavitation in pumps;
Process of cavitation in valves;
Process of cavitation in marine propellers;
Process of cavitation in mechanical heart valves;
Process of cavitation in large scale hydraulic flows;
Process of cavitation in turbulent flow contractions;
Difficulty in cavitation damage prediction;
Role of fluid properties on damage rates and severity; and
Techniques for troubleshooting and rectifying cavitation.

Intended Audience

This course is for anyone interested in hydraulics, hydrofoils in rotating equipment, or those who are generally inquisitive about the science of liquid and vapor interaction. It will also be informative for anyone who has boating or marine propulsion interests.

Benefits for Attendees

Attendees of this course will learn little known facts about the cavitation process and the broad range of circumstances in which cavitation occurs. Widely held misconceptions about cavitation are presented and debunked.

Course Content

The course content is in a PDF file (1438 KB) Interesting Facts (and Myths) about Cavitation.

Please click on the above underlined hypertext to view, download or print the document for your study.

Course Summary

Cavitation commonly occurs in hydroelectric turbines, hydraulic and marine structures, fluid power equipment, valves, and agitators. Cavitation has been documented in human heart mechanical valve implants. Detection of the cavitation phenomenon is not straightforward. Because cavitation is such a common detrimental occurrence, vast amounts of research have been conducted to understand the why, where, and when of the process. This course outlines the information about this phenomenon developed from this research.

Additional Resources

There is a wealth of published information on liquid cavitation. Here are some informative additional resources that will supplement the material presented in this course:

The cavitation home page at the University of Texas at Austin: http://cavity.ce.utexas.edu/
Comprehensive information about control valve cavitation: http://www.samson.de/pdf_en/l351en.pdf
Theory of cavitation and more specifically about bubble dynamics: http://caltechbook.library.caltech.edu/22/01/chap6.htm
Boat propeller cavitation: http://www.hydrocompinc.com/knowledge/library.htm

Quiz

Once you finish studying the above course content, you need to take a quiz to obtain the PDH credits.

DISCLAIMER: The materials contained in the online course are not intended as a representation or warranty on the part of PDH Center or any other person/organization named herein. The materials are for general information only. They are not a substitute for competent professional advice. Application of this information to a specific project should be reviewed by a registered architect and/or professional engineer/surveyor. Anyone making use of the information set forth herein does so at their own risk and assumes any and all resulting liability arising therefrom.