Go Back   Physics Help Forum > College/University Physics Help > Advanced Waves and Sound

Advanced Waves and Sound Advanced Waves and Sound Physics Help Forum

Reply
 
LinkBack Thread Tools Display Modes
Old Jan 9th 2019, 09:28 AM   #1
Junior Member
 
Join Date: Jan 2019
Posts: 5
Free surface flow

''' The surface can move with the fluid and so must be found as part of the solution '''; How can consider the surface as part of solution?! this topic is depends on flowing of fluid with free surface perturbed by an obstacle.
meriam04 is offline   Reply With Quote
Old Jan 9th 2019, 09:38 AM   #2
Senior Member
 
Woody's Avatar
 
Join Date: Jun 2016
Location: England
Posts: 750
It does seem like an invalid sentence,
however, without additional context,
it is difficult to decide if the sentence is wrong or just poorly worded.
__________________
~\o/~
Woody is offline   Reply With Quote
Old Jan 10th 2019, 02:15 AM   #3
Senior Member
 
Join Date: Oct 2017
Location: Glasgow
Posts: 291
Originally Posted by meriam04 View Post
''' The surface can move with the fluid and so must be found as part of the solution '''; How can consider the surface as part of solution?! this topic is depends on flowing of fluid with free surface perturbed by an obstacle.
Flow problems depend heavily on geometry as well as the relative flow speed, $\displaystyle U_{\infty}$. If a substance is flowing past an object and the object starts to move, the $\displaystyle U_{\infty}$ reduces relative to the surface of the object and the flow could be different.

Last edited by benit13; Jan 10th 2019 at 02:45 AM.
benit13 is offline   Reply With Quote
Old Jan 10th 2019, 02:37 AM   #4
Junior Member
 
Join Date: Jan 2019
Posts: 5
Originally Posted by Woody View Post
It does seem like an invalid sentence,
however, without additional context,
it is difficult to decide if the sentence is wrong or just poorly worded.
Please, take a look on page 02 pragraph 02 :
https://pdfs.semanticscholar.org/58a...6c20f52be0.pdf
meriam04 is offline   Reply With Quote
Old Jan 10th 2019, 03:12 AM   #5
Senior Member
 
Join Date: Oct 2017
Location: Glasgow
Posts: 291
Originally Posted by meriam04 View Post
Please, take a look on page 02 pragraph 02 :
https://pdfs.semanticscholar.org/58a...6c20f52be0.pdf
Yes, if you want to calculate any flows around some kind of object, the geometry of the object must be taken into account. If the object moves, that must also be taken into account.

As for how to take it into account? Perhaps it is discussed in the thesis you just linked?
benit13 is offline   Reply With Quote
Old Jan 10th 2019, 03:25 AM   #6
Junior Member
 
Join Date: Jan 2019
Posts: 5
Originally Posted by benit13 View Post
Yes, if you want to calculate any flows around some kind of object, the geometry of the object must be taken into account. If the object moves, that must also be taken into account.

As for how to take it into account? Perhaps it is discussed in the thesis you just linked?
But in this paragraph, he talked about the free surface without relating to an objects!
meriam04 is offline   Reply With Quote
Old Jan 10th 2019, 05:59 AM   #7
Senior Member
 
Join Date: Oct 2017
Location: Glasgow
Posts: 291
Originally Posted by meriam04 View Post
But in this paragraph, he talked about the free surface without relating to an objects!
That's fine. The same is true if the object is instead another fluid. Different fluids passing across each other interact in really interesting ways.
benit13 is offline   Reply With Quote
Old Jan 10th 2019, 09:34 AM   #8
Senior Member
 
Woody's Avatar
 
Join Date: Jun 2016
Location: England
Posts: 750
I took a look at Charlotte's thesis via your link
and it is as Benit points out.

The free surface she is describing is free to move as the fluid forces act upon it
rather than a fixed surface which will simply force the fluid out of the way.

The interface between two immiscible fluids is an obvious example,
indeed during my (very quick) scan of the thesis, I found that waves feature prominently.
__________________
~\o/~
Woody is offline   Reply With Quote
Old Jan 16th 2019, 01:05 PM   #9
Junior Member
 
Join Date: Jan 2019
Posts: 5
Originally Posted by Woody View Post
I took a look at Charlotte's thesis via your link
and it is as Benit points out.

The free surface she is describing is free to move as the fluid forces act upon it
rather than a fixed surface which will simply force the fluid out of the way.

The interface between two immiscible fluids is an obvious example,
indeed during my (very quick) scan of the thesis, I found that waves feature prominently.

But, she mentioned the word 'solution' ; Please, what solution she meant?
meriam04 is offline   Reply With Quote
Old Jan 17th 2019, 02:28 AM   #10
Senior Member
 
Join Date: Oct 2017
Location: Glasgow
Posts: 291
You know... form equations... then solve them... the result is the solution...

If you read the thesis, there is a literature review describing the equations used and solution methods. It seems that for most of the cases presented, the author calculates the pressure distribution across a fluid at some point in time (or as a function of time).

I'm not an expert on fluid mechanics, but the thesis seems very well written (as it should!) and at face value it seems there is plenty of information available in the text.
benit13 is offline   Reply With Quote
Reply

  Physics Help Forum > College/University Physics Help > Advanced Waves and Sound

Tags
flow, free, surface


« Quicksilver lamp | - »

Thread Tools
Display Modes


Similar Physics Forum Discussions
Thread Thread Starter Forum Replies Last Post
surface tension mak29 Thermodynamics and Fluid Mechanics 5 Dec 21st 2018 05:40 PM
surface tension mak29 Thermodynamics and Fluid Mechanics 1 Dec 5th 2018 10:06 AM
Calculating equal flow through parallel flow pipes? clone477 Thermodynamics and Fluid Mechanics 7 Mar 28th 2018 07:33 PM
multi-surface problem in refraction at spherical surface. asdfgh Advanced Optics 1 Feb 18th 2011 02:41 AM
controlling the inlet flow and outlet flow simonsam86 Thermodynamics and Fluid Mechanics 5 Sep 1st 2009 03:39 AM


Facebook Twitter Google+ RSS Feed