CFD Online Logo CFD Online URL
Home > Forums > Main CFD Forum

What is negative pressure meaning for a head?

Register Blogs Members List Search Today's Posts Mark Forums Read

LinkBack Thread Tools Display Modes
Old   March 27, 1999, 20:25
Default What is negative pressure meaning for a head?
Dong Li
Posts: n/a
I am doing some research for the head using in drive. Appreciated if somebody can explain how the negative presusure generate. Thanks in advance.
  Reply With Quote

Old   March 27, 1999, 22:10
Default Re: What is negative pressure meaning for a head?
Allan Morrison
Posts: n/a
To me your question is unclear - so I will try to answer what I think your question is. I will assume this is a very basic question about the units used to measure pressure.

1 ATM pressure = 101.3 kpa = 14.7 psi = 10.33 m of water etc. It is common in civil engineering to describe pressure in terms of equivalent height if water pressure as "head" pressure. Therefore a civil engineer could describe one atmospheric pressure as 10.33 meters of water. If the pressure is less than one atmosphere then the pressure is said to be negative (or a vacuum = the amount the pressure is BELOW atmospheric pressure). The units used are the same as those to measure the pressure above atmosphere so it can be said that a pressure that is negative 0.1 atmosphere = negative 1.033 meters of water pressure or a vacuum of +1.033 meters. Hope this is the answer you wanted. Otherwise please repost with more details.


  Reply With Quote


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
Physical meaning of pressure in pressure eqn dontknow Main CFD Forum 2 August 30, 2010 10:12
negative static pressure at inlet nino FLUENT 7 July 27, 2007 08:22
negative static pressure Selo melo FLUENT 5 December 18, 2006 10:30
Hydrostatic pressure in 2-phase flow modeling (CFX4.2) HB &DS CFX 0 January 9, 2000 14:19
Hydrostatic pressure in 2-phase flow modeling (long) DS & HB Main CFD Forum 0 January 8, 2000 16:00

All times are GMT -4. The time now is 12:24.