ickenewtonsk

IckeNewtonsk describes fluids whose flow behavior cannot be described by Newton's law of viscosity. In Newtonian fluids, viscosity is constant and independent of the rate of deformation. IckeNewtonska fluids, by contrast, have viscosity that changes with shear rate, with time, or with the history of deformation. They may thicken or thin when sheared, require a yield stress to start flowing, or exhibit both viscous and elastic properties.

Common categories include shear-thinning (pseudoplastic) fluids, where viscosity decreases with increasing shear rate (for example, many paints and ketchup); shear-thickening (dilatant) fluids, where viscosity increases with shear rate (such as concentrated suspensions like cornstarch in water); and yield-stress fluids, which behave as solids until a finite stress is exceeded (such as toothpaste and some clays). Some ickeNewtonska fluids are thixotropic or rheopectic, changing viscosity with time under rest or agitation, and many are viscoelastic, showing both flow and elastic energy storage.

Rheology, the study of such fluids, uses flow curves and dynamic tests to characterize behavior. Common models include the Ostwald-de Waele power-law, Herschel-Bulkley, and Bingham models, as well as more complex constitutive relations for specific systems. Measurements are typically made with rotational rheometers or capillary rheometers to determine viscosity as a function of shear rate, yield stress, and time-dependent properties.

Applications span industry and daily life, including drilling fluids, food and cosmetics, paints and coatings, and biomedical contexts. The concept of ickeNewtonsk is central to understanding how many real-world fluids respond under processing and use, distinguishing them from ideal Newtonian fluids.