Why water compressibility is neglicable

  • Context: Undergrad 
  • Thread starter Thread starter bigbrother
  • Start date Start date
  • Tags Tags
    Compressibility Water
Click For Summary

Discussion Overview

The discussion centers around the concept of compressibility, specifically comparing the compressibility of water, oil, and synthetic oils. Participants explore definitions, implications of compressibility in different fluids, and the conditions under which the incompressible assumption may be applied.

Discussion Character

  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • Compressibility is defined as the change in volume with change in pressure, or change in density with respect to pressure.
  • Water's density varies only about 2% up to pressures of about 7000 psi, suggesting it can often be treated as incompressible.
  • Some participants express uncertainty about the compressibility of oil compared to water, seeking clarification on whether they are similar.
  • One participant notes that both water and oil can be considered incompressible up to very high pressures, but specific numerical comparisons are not provided.
  • A link to a resource on bulk modulus is shared, but its implications for the discussion are not fully explored.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the compressibility of oil compared to water, with some suggesting they are similar while others seek further confirmation and clarification.

Contextual Notes

The discussion lacks specific numerical data on oil compressibility and relies on generalizations about incompressibility without resolving the differences between fluids under varying conditions.

Who May Find This Useful

Individuals interested in fluid mechanics, engineering applications involving fluid dynamics, and those studying the properties of different fluids under pressure may find this discussion relevant.

bigbrother
Messages
4
Reaction score
0
can anyone help me to have simple definition for compressibility and oil compressibility and why water compressibility is neglicable and for synthetic oils what is the effect of compressibilit on them compared to wter and diesel
 
Physics news on Phys.org


Compressibility can be looked at as the change in volume with change in pressure. Or, similarly, you can look at in terms of change in density with respect to pressure.

If you look at the density of air over a range of pressures, you'll see that it doesn't take much pressure to have a significant affect on the density. However water's density will only vary about 2% up to pressures of about 7000 psi.

It is a judgment call on whether or not to use the incompressible assumption or not.
 


many thanks for your response but kindly could you advice about the oil comperssibility compared to water
 


They are both incompressible up to some very large pressures. I'll see if I can't dig some actual numbers up.
 


many thanks for this valuable link
but could you please confirm with me what i understood from this is that oil comperssibility is the same as water,no great diferrences between them
is that true
 

Similar threads

High School Why is my experimental spring constant an order of magnitude off?
  • · Replies 4 ·
Replies
4
Views
2K
High School How to advoid water condensation in compressed air piping
  • · Replies 2 ·
Replies
2
Views
2K
Undergrad Compressed air Pushing a Column of Water
  • · Replies 11 ·
Replies
11
Views
4K
High School The physics of flywheel launchers (like tennis ball shooters)
  • · Replies 60 ·
3
Replies
60
Views
7K
Undergrad Will This Friction Clamp Hold the Weight?
  • · Replies 10 ·
Replies
10
Views
2K
Undergrad How Does Pressure Affect the Boiling Point of Water?
  • · Replies 2 ·
Replies
2
Views
7K
Undergrad Sound waves in a 'compressed' liquid
  • · Replies 6 ·
Replies
6
Views
2K
Graduate Divergence of downhill flowing water
  • · Replies 11 ·
Replies
11
Views
2K
High School Compressing Water: Can It Be Done?
  • · Replies 3 ·
Replies
3
Views
5K
Graduate Compression of air entrained in water
  • · Replies 4 ·
Replies
4
Views
3K