If we speak of Pseudoplastic these are ones that are believed to exhibit common behavior of both plastic flow and Newtonian flow. (14.37) has two domains of solution which interconnect at r = R0. γ At both sufficiently high and very low shear rates, viscosity of a polymer system is independent of the shear rate. the velocity profile is flat. Such a flow behaviour is called pseudoplastic. The bubbly flow in an internal airlift loop reactor is simulated with a steady Reynolds averaging two‐fluid model combined with a validated two‐phase flow k‐ϵ turbulence model. FIGURE 5.20. On the other hand, reversible materials, such as agar and impression compound, soften upon heating and solidify slightly above body temperature with no chemical change taking place. Polymer viscosity at different shear rates. 5.4, the calculated µp at any shear rate can never be higher than at zero shear rate. [CLICK] Therefore, they must be mixed manually on a mixing pad. The surface of a Bingham plastic can hold peaks when it is still. K g ) ⋅ . An example of dilatant fluid is sand in water. Thermal Properties. The condition for non-flow is then: Figure 2.9. There are not as many natural dilatants, although certain proportions of sand and water mixed together can display dilatant properties. 14.13, it is seen that at a radial position r = R0 both dv/dr and τrz change signs. Substitution, followed by integration, gives the velocity profile as follows: The velocity profile is clearly not parabolic as in the case of Newtonian flow (s = 1). Examples An example of a plastic material is toothpaste. ) 16.3. On the other hand, when r > R0, the right-hand side of the equation has a negative sign, since R02r