Rice kheer is prepared by boiling rice in milk (@ 6-7 g of rice/100 g milk) and then simmerring gently till rice grains are softened and begin disintegrating). With reference to the question, consider just the rice-milk mix (without any other ingredient) heated in an indirect heat exchanger using steam as heating agent. Will the rice-milk mix inside the heat exchanger behave like a Newtonian or non-Newtonian fluid?
Sure, it is non-Newtonian behavior. However, proper characterization needs proper measurement. If you use oscillatory rheology, you can find gel point if it will have. You can characterize viscoelastic properties and even you can predict solid-like or liquid-like behavior. Steady shear measurement will provide you yield and then you can use HB model or power type relationship to further characterize.
Sure, it is non-Newtonian behavior. However, proper characterization needs proper measurement. If you use oscillatory rheology, you can find gel point if it will have. You can characterize viscoelastic properties and even you can predict solid-like or liquid-like behavior. Steady shear measurement will provide you yield and then you can use HB model or power type relationship to further characterize.
Sure. it is non newtonian fluid.In order to describe the variation in the rheological
properties of samples under steady shear, the data
were fitted to the well-known power law model
(Eqn. 1), which is used extensively to describe
the flow properties of non-Newtonian liquids
in theoretical analysis as well as in practical
engineering applications (21).
= Kn (1)
where,
= the shear stress (Pa),
= the shear rate (s-1),
K = the consistency index (Pa sn),
n = the flow behaviour index (dimensionless).
Reference :EFFECTS OF OZONATION ON THERMAL,
STRUCTURE AND RHEOLOGICAL PROPERTIES OF RICE
STARCH IN AQUEOUS SOLUTION
Rice-kheer constitutes a two-phase system with rice as a dispersed phase in the milk that acts as the continuous phase. Rheology of two-phase systems is well-studied and methods to characterize the flow behavior of such systems are equally well documented. Under certain shear-rate conditions, rice-kheer could behave as a Newtonian fluid while, in general, in the common range of shear rates, it should show non-Newtonian characteristics. For understanding the deformation response of rice-kheer, you could borrow ideas discussed in the book Aroon V. Shenoy, Rheology of Filled Polymer Systems, Kluwer Academic Publishers, Netherlands (1999). If you are specifically looking for heat transfer behavior in non-Newtonian fluids, then you could look up the following: A. V. Shenoy, Natural convection heat transfer to power-law fluids, Handbook of Heat and Mass Transfer, Gulf Publishing Company, Houston, Tx, Vol. 1, Chapter 5, p. 183 (1986). A. V. Shenoy, Natural convection heat transfer to viscoelastic fluids, Encyclopedia of Fluid Mechanics, Gulf Publishing Company, Houston, Tx, Vol. 7, Chapter 10, p. 287 (1988). A. V. Shenoy, Non-Newtonian fluid heat transfer in porous media, Advances in Heat Transfer, Academic Press, N. Y., Vol. 24, p. 101 (1994).
In my opinion rice kheer can't be think as a single phase fluid. Because of the presence of rice, it will be like solid-fluid mixture, whose universal properties will be difficult to determine. If one tries to measure the rheology response of rice kheer it will depend how rice particles are distributed in milk. The distribution of rice particles may be different at different time, and hence the rheology measurements.
In other non-Newtonian fluids for examples slurries, the solid particles are so fine that they mix homogeneously in water and will be difficult to observe as an independent particles unless they start settling down under very low flow conditions. In contrast to that in rice kheer, rice particles can be easily observed. Therefore if one need to model the behaviour of flow of rice kheer, one should consider a mixture of Newtonian fluid (milk) and solid particles (rice).
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