HTHS calculation

[GMorg]

Does anyone here know if HTHS can be calculated (as opposed to measured). If so, can someone share an equation that describes HTHS of two mixed fluids?

 

[TallPaul]

I suppose the closest we are going to get (and it may not be very close) is to run the two fluid's HTHS numbers throught the oil blending equation.

 

[mechtech]

It would probably be a litle less than the calculated average.

 

[Mitch Alsup]

And don't forget to convert from cSt to cP.

 

[TallPaul]

Exactly. The viscosity calculator will do that. When you 50/50 combine a 12 cSt with a 14 cSt the difference is insignificant (12.96 vs 13), but try some 100 cSt additive on a 30 weight and the blender will come up much lower than arithmetic mean.

If you have a decent calculator you can do it yourself. The blended viscosity is the antilog of the weighted averages of the logs of each oil mixed into the blend (or simply 10 raised to the "weighted averages of the logs of each oil" power.