Is it possible to define custom fluid properties?

[billtubbs]

Hi, this package looks interesting and I would like to use it. But my application requires calculating properties for SYLTHERM 800 which is a thermal oil produced by Dow.

As far as I can tell this is not built in, but I'm struggling to determine if it's possible for the user to define their own fluids.

I'm interested in the following properties and modelling how they vary with temperature using simple empirical models based on the manufacturers property table.

• Heat capacity
• Density
• Thermal conductivity
• Viscosity
• Vapor pressure

So I guess I would prefer not to define every possible property if I don't need them.

Please advise if / how I might do this.

[CalebBell]

Hi Bill,
Yes, thermo supports user-defined fluids; the Flasher based interface allows components to be created by the user and does not require all properties to be entered. Some properties may be unavailable if not defined or estimated by low accuracy methods like liquid viscosity.
A complete example of using a heat trasnfer fluid is here:
https://thermo.readthedocs.io/Examples/Working%20with%20Heat%20Transfer%20Fluids%20-%20Therminol%20LT.html
Sincerely,
Caleb

[billtubbs]

I asked Claude to look into adapting the Therminol LT example and it pointed out that SYLTHERM 800 is a hydrocarbon mixture, not a single chemical component like Therminol LT. Furthermore we don't know the molecular weight of SYLTHERM.

Are these surmountable issues? Any advice on how to easily do it?
Thanks for your help.

[billtubbs]

Actually, just realized it's 98% Polydimethylsiloxane (PDMS) so approximately not a mixture. So this may not be as much of a problem as I thought.