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cuspaceflight / bamboo

Cooling system modelling for liquid rocket engines.
GNU Affero General Public License v3.0
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Water model for thermo vs CoolProp #19

Closed dug20 closed 3 years ago

dug20 commented 3 years ago

Large discrepancies between CoolProp and thermo when using water in the coolant jacket. I'm not sure if there's a bug with the implementation of thermo (maybe it's using the transport properties for steam for some reason?).

Pressure is no higher than 20 bar, which should apparently give a boiling point of 212.5 deg C (https://www.engineeringtoolbox.com/boiling-point-water-d_926.html), so coolant boil-off would not be expected I think.

CoolProp pure water cooling jacket thermo pure water cooling jacket

dug20 commented 3 years ago

Pressure drop plot when using thermo (the CoolProp one is indistinguishable). 19.5 bar corresponds to a water boiling point of 211.2 deg C.

image

dug20 commented 3 years ago

May have to force thermo to use liquid properties - e.g. chemical.kl and chemical.mul instead of chemical.k and chemical.mu

dug20 commented 3 years ago

Added a 'force_phase' argument to the TransportProperties class, which lets you force thermo to use a certain phase (e.g. liquid or gas) when calculating transport properties. The results when using thermo now align well with CoolProp:

image