I call non-Newtonian fluids rascals because they do not follow the rules. Every time I review the characteristics of both fluids, I get caught up in the overwhelming array of nomenclature and technical terms. Fluids fall into two classifications-Newtonion or non-Newtonion. Chapters from Biophysics.Before you select a pump for any service, you need to know and understand the characteristic properties of the fluid you wish to pump. Portal:Questions_for_final_examination_in_biophysics_(2._LF_UK,_GM)īlood flow Bibliography Īmler E. Biological fluids: blood, saliva, semen, mucus, synovial fluid.Natural substances: magma, lava, extracts and gum.Foods: ketchup, mayonnaise, soup, butter, jam, yogurt.Medicine - understand more about our body and improve health tecniques.Safety - creating body vest / armours that behave like non-Newtonian fluids for Police or Military uses.Prevent disasters - planning the place to construct a house or building depending on the soil of the terrain.Understanding the behaviour of non-Newtonian fluids has important applications: Stress depends on normal and shear strain rates and also the pressure applied on it Nail polish, whipped cream, ketchup, syrups, paper pulp in water, latex paint, ice, blood, some sillicone oils and some sillicone coatings
Suspensions of corn starch in water (Oobleck), sand in waterĪpparent viscosity decreses with increased stress Yogurt, xanthan gum solutions, aqueous iron oxide gels, gelatin gels, pectin gels, synovial fluid, hydrogenated castor oil, some clays, carbon black suspension in molten tire rubber, some drilling muds, many paints, many colloidal suspensionsĪpparent viscosity increases with increased stress Some lubricants, whipped cram, Silly PuttyĪparrent viscosity increases with duration of stressĪpparent viscosity decreases with duration of stress "Parallel" linearstic combination of elastic and viscous effects Instead, they are studied best through several other rheological proprieties that relate to stress and strain rate tensors under many different flow conditions which are measured using different devices or rheometers.Ĭomparating Viscoelastic, Non-Newtonian and Newtonian proprieties we can observe: In case of the Non-Newtonian fluids, the concept of vicosity usually used in fluid mechanics to characterize the shear proprieties of a fluid is not quite adequate. In a Non-Newtonian fluid the relation between the shear stress and the shear rate is different and can even be time-dependent (Time Dependent Viscosity) - a constant coefficient of viscosity cannot be defined for Non-Newtonian fluids as its possible for Newtonian fluids. In a Newtonian fluid the relation between shear stress and the shear rate is linear, passing through the origin, the constant of proportionality being coefficient of viscosity. The result of that stress is described as strain. In science, stress means that a force is applied to a body. Usually, the viscosity of non-Newtonian fluids is dependent on shear rate or shear rate history, or their viscosity is shear independent but still exhibit normal stress-differences or other Non-Newtonian behavior. The viscosity changes as the force applied changes. Non-Newtonian fluids have viscosities that change according to the amount of force that is applied upon the fluid. The viscosity remains constant as the force applied changes. For example: fluids like water, have lower viscosity unlike fluids such as honey or syrup.įor Newtonian fluids, changing the force you apply to the fluid will not change their viscosity. Viscosity, measures a fluids ability to resist gradual deformation by shear or tensile stresses, in other words, is a propriety that measures how easily a fluid move: if a fluid has high viscosity, then the fluid will move slower if a fluid has low viscosity, then it will move faster. Newtonian fluids have a constant viscosity (flow). Two types of fluids exist: Newtonian fluids and Non-Newtonian fluids. Non-Newtonian fluid Ī Non-Newtonian fluid is a fluid whose flow ( viscosity) properties differ from those of Newtonian fluids, described by Sir Isaac Newton. 1.2 Types of Non-Newtonian fluid behaviour.1.1 Newtonian fluid VS Non-Newtonian fluid.
0 kommentar(er)
