Talk:Non-Newtonian fluid
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Blood
- Blood shows up in two seemingly mutualy exclusive examples. Anyone know the correct answer?
Classification of generalized Newtonian fluids
- I think that the table in the article could be improved. For example, it shows (or suggests) that power-law fluids, Bingham plastics, and generalized Newtonian fluids are distinct categories of non-Newtonian fluids. Rheology and fluid mechanics textbooks classify power-law fluids and Bingham plastics as subsets of generalized Newtonian fluids. (A clarification concerning this point would also address the confusion over the classification of blood, noted in the preceding section.) YinDW 00:15, 12 Jan 2005 (UTC)
Proposed new table
I think YinDW is right, I think the table is just confusing. Many of the attributes of non-Newtonian fluids are orthogonal; it is, for example, possible to have a dilatant material that exhibits viscoelasticity (Silly Putty), or a plastic solid that is Newtonian past the yield point (grease). How's this:
| Type of fluid | Also known as | Behaviour |
| Dilatant | shear thickening | viscocisty increases as shear rate increases |
| Pseudoplastic | shear thinning | viscosity decreases as shear rate increases |
| Thixotropic |   | viscocity decreases with duration of shearing force |
| Rheopectic |   | viscocity increases with duration of shearing force |
| Viscoelastic |   | fluid will rebound when shear force is removed |
| Plastic solid |   | substance that will not flow with shearing force below a threshold called the yeild point |
And it should be pointed out explicitly that many non-Newtonian fluids exhibit more than one characteristic; perhaps a chart that lists substances in the left column, and the non-Newtonian characteristics to the right:
| Substance | Non-Newtonian properties |
| Silly Putty | Viscoelastic, shear thickening |
| Lubricating grease | Plastic solid |
| Ketchup | Thixotropic, pseudoplastic |
| Gypsum paste | Rheopectic |
And as should be apparent from the horrid formatting of my tables, I'll probalby need some help cleaning them up if I do this... scot 20:30, 4 Mar 2005 (UTC)
I saw the recent reports of research on shear thickening fluid based composites for body armor. Damnit, I should have patented that when I first thought of it, over 15 years ago. Never did get around to putting together a sample of Silly Putty and Kevlar composite and shooting it, however... scot 14:55, 25 Mar 2005 (UTC)
External links of interest
http://www.research-equipment.com/viscosity%20chart.html http://www.edasolutions.com/Groups/sizepump.htm