Thermodynamics and Fluid Mechanics Thermodynamics and Fluid Mechanics Physics Help Forum

 Feb 12th 2018, 12:10 PM #1 Member   Join Date: Mar 2013 Posts: 32 capillary Does the height of liquid in a capillary tube increase with an increase in temperature? If the liquid is water or another liquid.
 Feb 12th 2018, 04:09 PM #2 Senior Member   Join Date: Apr 2015 Location: Somerset, England Posts: 1,028 There is no simple answer to this. A simple formula for the capillary rise , h is h = 2TcosL / r p g T is the surface tension, L is the contact angle, r is the tube radius p the liquid density and g the gravitational acceleration. Now both the surface tension and the density decrease with increasing temperature. The tube radius will increase. the other quantities are unaffected. So it depends upon the relative changes for the liquid concerned. In general the surface tension will win out and the upstanding column will fall slightly. Somewhere near the liquids 'critical temperature' the surface tension will reduce to zero and the rise will disappear altogether. benit13 likes this.
 Feb 12th 2018, 11:29 PM #3 Member   Join Date: Mar 2013 Posts: 32 The tube radius is constant. If surface tension increases, adhesion will be bigger and the liquid will rise with increasing temperature?

 Tags capillary

 Thread Tools Display Modes Linear Mode

 Similar Physics Forum Discussions Thread Thread Starter Forum Replies Last Post capillaryQuestions Advanced Thermodynamics 1 Apr 29th 2014 09:39 AM r.samanta Thermodynamics and Fluid Mechanics 2 Oct 19th 2009 05:07 AM mint Thermodynamics and Fluid Mechanics 1 May 9th 2009 10:31 PM MathGuru Thermodynamics and Fluid Mechanics 1 Aug 1st 2008 11:56 AM