IDEA viscosity

mfmohdyasin · March 14, 2011, 08:33

Dear all,
I tried to plot the Dynamic viscosity of different fuels that are implemented in OpenFOAM using the function given in NSRDSfunc1.H and the coefficients given in liquids/IDEA.C.

Based on the plot that I attached, IDEA dynamic viscosity increases after about 550K which is not physical. Does anyone know about this issue?

Best
Fairus

niklas · March 14, 2011, 12:54

Hmmm...I added that. I will look into it tomorrow.

niklas · April 7, 2011, 08:46

Its because the alphaMethyl napthalene properties are the way they are.
I have checked the numbers and they are correct as according to the NSRDS tables.

check the viscosity of aC11H10 and you will see how it looks.

for more info on how the idea fuel was constructed look into the file
src/thermophysicalModels/liquids/IDEA/IDEA.H

N

niklas · April 7, 2011, 08:50

looking into the table again I see that the valid temperature range for the liquid viscosity is only
250-450 K, which might explain the behavior.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Eulerian Modeling: Frictional Viscosity Help	meangreen	FLUENT	1	January 25, 2018 16:13
Turbulence viscosity limited	Madhukar Rapaka	FLUENT	0	June 26, 2006 04:17
kinematic viscosity at diff temperatures,pressures	Mecobio	Main CFD Forum	0	November 7, 2005 13:55
Turbulent viscosity in a riser	ap	FLUENT	8	April 19, 2003 09:00
Problem of Turbulent Viscosity Ratio Limited	David Yang	FLUENT	3	June 3, 2002 07:13

March 14, 2011, 12:54		#2
niklas Super Moderator Niklas Nordin Join Date: Mar 2009 Location: Stockholm, Sweden Posts: 693 Rep Power: 29	Hmmm...I added that. I will look into it tomorrow.

April 7, 2011, 08:46		#3
niklas Super Moderator Niklas Nordin Join Date: Mar 2009 Location: Stockholm, Sweden Posts: 693 Rep Power: 29	Its because the alphaMethyl napthalene properties are the way they are. I have checked the numbers and they are correct as according to the NSRDS tables. check the viscosity of aC11H10 and you will see how it looks. for more info on how the idea fuel was constructed look into the file src/thermophysicalModels/liquids/IDEA/IDEA.H N

April 7, 2011, 08:50		#4
niklas Super Moderator Niklas Nordin Join Date: Mar 2009 Location: Stockholm, Sweden Posts: 693 Rep Power: 29	looking into the table again I see that the valid temperature range for the liquid viscosity is only 250-450 K, which might explain the behavior.