How to calculate various constants like consistency index and flow behavior index, used in the Herschel Bulky model from exp data (shear stress vs shear rate) in Origin or excel?
If I need to calculate constants and other values used in Casson fluid model, how can I calculate them using Origin or Excel?
Dear Dr. Mayank Srivastava
If you have the data, you can use Rheocalc software for that,
Regards,
Akram
Akram Jassim Jawad ....I suppose that such software is to be helpful only when used with the Rheometer of certain model.
I personally dont own rheometer in my lab, but have the data of shear stress, shear rate, viscosity etc.with me...
Mayank Srivastava
I think you can use OriginPro program to create an ideal equation as a model, then you can calculate fitting values between experimental and theoretical data.
Regards.
From the shear stress -shear rate data you can calculate the parameters of the Herschel Bulky model such as yelid stress, consistency coefficient and flow behavior index using your rheometer software or you can curve fitting statistical software using non linear estimation method. If you have any doubt free fell to contact me trough mail of my mail id [email protected]
The rheometer manufacturer should provide the appropriate software. Thanks to this, we do not have to transfer data. If not, the nonlinear regression method based mainly on the Marquardt-Levenberg algorithm is available in many popular programs: Statistica, MATLAB, Origin etc. But it's best to learn to program yourself. Then we really know what we're counting.
Thank you everyone for your much needed help. I have curve fitted the data using Origin Pro.
Regards
Mayank Srivastava, Original Pro is only a tool. The built-in algorithms will not select the approximating function. This you can do. By the way, what function / equation did you ultimately choose to describe the flow curve?
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