# Numerical error in two phase flow simulation

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 October 24, 2015, 05:36 Numerical error in two phase flow simulation #1 New Member   Shobit Garg Join Date: Oct 2015 Posts: 2 Rep Power: 0 I am trying to simulate regimes occurring after a drop falls on a liquid pool using in-house code. However there seem to errors in the solution - 1.) We are using levels set approach to get the interface. However we are getting mass loss in the drop (we are reinitializing the level set.) 2.) The drop, when it reaches near the pool, suddenly shoots upwards. This is against gravity. Please help me to find why we are getting these errors. Time step - 10E-7 Grid - 450*1000

October 24, 2015, 06:29
#2
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Michael Prinkey
Join Date: Mar 2009
Location: Pittsburgh PA
Posts: 363
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Quote:
 Originally Posted by cfdamateur I am trying to simulate regimes occurring after a drop falls on a liquid pool using in-house code. However there seem to errors in the solution - 1.) We are using levels set approach to get the interface. However we are getting mass loss in the drop (we are reinitializing the level set.) 2.) The drop, when it reaches near the pool, suddenly shoots upwards. This is against gravity. Please help me to find why we are getting these errors. Time step - 10E-7 Grid - 450*1000
I don't think anyone can offer much advice to you given so little information. Do you have a reference for the algorithm that your code implements? Is your grid Cartesian? Is there grid stretching? What is the density ratio between the two fluids?

October 24, 2015, 06:48
#3
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Shobit Garg
Join Date: Oct 2015
Posts: 2
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Quote:
 Originally Posted by mprinkey I don't think anyone can offer much advice to you given so little information. Do you have a reference for the algorithm that your code implements? Is your grid Cartesian? Is there grid stretching? What is the density ratio between the two fluids?
Ohk..sorry for that. So we are trying to implement coupled level set volume of fluid method on an axisymmetric case. Our grid is Cartesian and I guess no grid stretching. Two fluids are water and oil so density ratio (oil/water) of about 0.86.