AllExperts > Aeronautical Engineering 
Search      
Aeronautical Engineering
Volunteer
Answers to thousands of questions
 Home · More Aeronautical Engineering Questions · Answer Library  · Encyclopedia ·
More Aeronautical Engineering Answers
Question Library

Ask a question about Aeronautical Engineering
Volunteer
Experts of the Month
Expert Login

Awards

About Us
Tell friends
Link to Us
Disclaimer

 
 
 
 
About Paul Soderman
Expertise
Aeronautics, Fluid Mechanics, Aeroacoustics, Noise Control, Muffler Design, Wind Tunnel Research.... I know nothing about India - do not ask about schools, jobs, application requirements, career choices, etc. for India. Please, no text message verbiage; I prefer full words in full sentences. Thanks.

Experience
38 years as research engineer at NASA

Publications
AIAA, NASA

Education/Credentials
B.S. and M.S. Aeronautical Engineering - U. of Washington Graduate work Standford U.

Awards and Honors
AIAA Associate Fellow (American Institute of Aeronautics and Astronautics)

 
   

You are here:  Experts > Science > Aerospace/Aviation > Aeronautical Engineering > Gas pressurized vessel

Aeronautical Engineering - Gas pressurized vessel


Expert: Paul Soderman - 11/5/2009

Question
Hello Paul,
I am trying to understand the relationship’s involved with a carbon fiber pressure vessel filled with a compressed gas / air at 4500psi. The volume of the vessel is 20inch^3. How would I calculate the amount of volume of gas and speed of the gas being release so that the constant flow would last 15 minutes?  Also any material you could refer me to help understand solving the problem would be appreciated.

If you were not the right person to ask this question to, could you please refer me to a expert that might be able to help or point me in the right direction because I have found it very difficult to find any material  on the internet about solving this problem.

Thank you for your help Paul.
-Russell

Answer
Russell
Assuming ambient temperature, the ideal gas laws indicate that your vessel would contain 0.27 lb of air and would expand to about 6115 in^3 at atmospheric pressure.  But the velocity and time of discharge is complicated by the fact that the flow starts out supersonic.  As the pressure in the vessel decreases the velocity decreases and eventually goes subsonic.  Without some kind of variable throttle it would not be possible to hold constant flow rate.  Knowing more about the problem I might be able to solve it, but you haven't explained your objectives or constraints.  An expert in gas dynamics could solve this for you.  I haven't worked this kind of problem in 40 years and would have to dig out my old text books to spin up.  So unless it is really important, I will have to pass.
Paul

Add to this Answer   Ask a Question


 
User Agreement | Privacy Policy | Kids' Privacy Policy | Help
Copyright  © 2008 About, Inc. AllExperts, AllExperts.com, and About.com are registered trademarks of About, Inc. All rights reserved.