'Performance of a split air-conditioner in a domestic setting' simulation project by pankajkumar979


#1

I created a new simulation project called 'Performance of a split air-conditioner in a domestic setting':

Aim of this project is to assess the performance of a Split air-conditioner and to compare it with analytic calculations.


More of my public projects can be found here.


#2

Description

Objective of this project is to compare the results of two different Turbulence models i.e. K-epsilon and the SST -k- \omega. Requirements of two models are different and depends on the y+ value at the boundary.

Flow near the wall is divided into three layers:

  1. Viscous sublayer or laminar sublayer.
  2. Buffer layer.
  3. Log-law region.


By aokomoriuta(青子守歌) (Own work) [CC BY-SA 3.0 (https://creativecommons.org/licenses/by-sa/3.0) or GFDL (http://www.gnu.org/copyleft/fdl.html)], via Wikimedia Commons

Above figure shows the mean velocity distribution adjacent to a smooth wall, showing the logarithmic distribution away from the viscous region next to the wall and the linear region in the viscous sublayer.

Following link shows a fantastic discussion on various turbulence models:

From the above two links we understand that in case of k epsilon model, wall functions are used for the analytic flow calculation in the viscous sublayer near the wall. The technique offers good convergence and isn’t memory-intensive. In order to not resolve the viscous sub layer, y+ values are calculated and if the mesh satisfies 30 < Y+ < 300, then k-epsilon model and the wall functions are used.

For using the SST k-\omega, Y+ values are kept to the minimum i.e. y+~1 as this model resolves till the laminar sublayer.


Figure shows the Geometry of the model.
sstvelocitz
Velocity distribution
Velocity
Temp


Streamlines


#3

Nice one @pankajkumar979!!