Thermophysical properties of lubricants
Thermophysical properties of lubricants
(OP)
Hi all,
I'm looking for the thermophysical and transport properties(density, specific heat, thermal conductivity, kinematic or dynamic viscosity, surface tension, etc.) of lubricants as cooling/heating media.
I'd found out something on:
a) Neale's Tribology Handbook, but he points out - except the viscosity - generic/average values (Btw: we know that all properties are strongly sensitive to the temperature);
b) Rosenhow-Hartnett's, Handbook, Kays-Crawford's textbook Convective Heat and Mass Transfer, and others ref. books, but all of them list the properties for generic mineral oils.
Do you know any other reference handbooks/textbooks or web sites (or lubricants producers) where reliable thermophysical and transport data on lubricants are shown?
Thanks very much in advance for the help.
Gianfranco
lopad@tin.it
I'm looking for the thermophysical and transport properties(density, specific heat, thermal conductivity, kinematic or dynamic viscosity, surface tension, etc.) of lubricants as cooling/heating media.
I'd found out something on:
a) Neale's Tribology Handbook, but he points out - except the viscosity - generic/average values (Btw: we know that all properties are strongly sensitive to the temperature);
b) Rosenhow-Hartnett's, Handbook, Kays-Crawford's textbook Convective Heat and Mass Transfer, and others ref. books, but all of them list the properties for generic mineral oils.
Do you know any other reference handbooks/textbooks or web sites (or lubricants producers) where reliable thermophysical and transport data on lubricants are shown?
Thanks very much in advance for the help.
Gianfranco
lopad@tin.it





RE: Thermophysical properties of lubricants
You should bear in mind though that those data relate to the use in heating systems. This means that usually non-laminar flow exists and that there are restrictions to the maximum heatflux that is allowed to avoid local cracking of the fluid.
In an engine the oilflow is usually laminar - which means that the heattransporting capacity is much lower - whereas the heatflux might be much higher locally. The latter in these applications is not usually a problem because the oil is changed frequently.
RE: Thermophysical properties of lubricants
RE: Thermophysical properties of lubricants
Therminol
Dow
RE: Thermophysical properties of lubricants
Thanks for your useful obs/data.
Gianfranco
RE: Thermophysical properties of lubricants
viscosity/temperature: as per the ASTM chart, the abscissa is log10ToC, the ordinate is log10log10(cS+0.6). The chart works so well that the viscosity-temperature characteristics are frequently specified as "ASTM slope".
specific heat, Cp, J/kgK:
where s is the specific gravity at 60oF.
thermal conductivity, K, W/mK: for a rough estimation,
thermal diffusivity, d, m2/s:
where rho is the density [kg/m3].
RE: Thermophysical properties of lubricants
The relationship given in ASTM D341 (viscosites over 2cst)
Log10.log10(v + 0.7) = A-B.log10(T+273) where v is kinematic viscosity in Cst at T degC. Sorry i am not allowed to say which oil company nor what relationship.
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I am curious about the relationship refreenced to from Stachowiak and Batchelor as this differs from the ASTM equation i have beeen using for everything from quench oils to asphalts, including lubricants and fuel oils. Do you have a reference to the ASTM standard from which this is taken? There are a variety of these equations used, some open to very poor results if misused such as the Shell V50 equation (designed for a specific case and often misapplied).
RE: Thermophysical properties of lubricants
RE: Thermophysical properties of lubricants