Note: This discussion is about an older version of the COMSOL Multiphysics® software. The information provided may be out of date.

Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.

Heat Transfer

Please login with a confirmed email address before reporting spam

I am trying to design a model which will b use for heat transfer .I am trying to design this model in Nanomete Scale (Surface and Rod).Rod i put on the surface and i did simulation but no change in temperature bottom side and top side .First it showed error then i removed error .now how can i get temperature variation??

4 Replies Last Post Oct 30, 2016, 10:57 a.m. EDT

Please login with a confirmed email address before reporting spam

Posted: 7 years ago Oct 23, 2016, 4:19 a.m. EDT

I am trying to design a model which will b use for heat transfer .I am trying to design this model in Nanomete Scale (Surface and Rod).Rod i put on the surface and i did simulation but no change in temperature bottom side and top side .First it showed error then i removed error .now how can i get temperature variation??


In nanoscale you won't get any temperature differences because heat transfer is so fast. You can compare this with the famous Einstein formula for diffusion length, d ~ sqrt(D*t), i.e. the time in which particle leaps over the distance d is d^2/D. If d = 100 nm and D = 1e-5 cm^2/s, time needed is 10 microsec. Heat transfer is even more efficient, temperature differences disappear in nanoseconds in nanoscale.

BR
Lasse
[QUOTE] I am trying to design a model which will b use for heat transfer .I am trying to design this model in Nanomete Scale (Surface and Rod).Rod i put on the surface and i did simulation but no change in temperature bottom side and top side .First it showed error then i removed error .now how can i get temperature variation?? [/QUOTE] In nanoscale you won't get any temperature differences because heat transfer is so fast. You can compare this with the famous Einstein formula for diffusion length, d ~ sqrt(D*t), i.e. the time in which particle leaps over the distance d is d^2/D. If d = 100 nm and D = 1e-5 cm^2/s, time needed is 10 microsec. Heat transfer is even more efficient, temperature differences disappear in nanoseconds in nanoscale. BR Lasse

Please login with a confirmed email address before reporting spam

Posted: 7 years ago Oct 29, 2016, 10:22 a.m. EDT
Thanks sir
Thanks sir

Please login with a confirmed email address before reporting spam

Posted: 7 years ago Oct 29, 2016, 11:31 a.m. EDT
Dear Sir ,
But I want to Nano-Modification to enhance the surface area .how it possible?Is it Possible to make separately surface in nanometer scale and rod will meter scale ??
Dear Sir , But I want to Nano-Modification to enhance the surface area .how it possible?Is it Possible to make separately surface in nanometer scale and rod will meter scale ??

Please login with a confirmed email address before reporting spam

Posted: 7 years ago Oct 30, 2016, 10:57 a.m. EDT
I do not believe that it is possible, but I am not 100% sure.
I do not believe that it is possible, but I am not 100% sure.

Note that while COMSOL employees may participate in the discussion forum, COMSOL® software users who are on-subscription should submit their questions via the Support Center for a more comprehensive response from the Technical Support team.