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


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.



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.
Velocity distribution



Nice one @pankajkumar979!!