In an ideal flow, there is no existence of shear force because of vanishing viscosity. Figure Shear stress and deformation rate relationship of different fluids. For a fluid, the relationship between shear stress and shear strain is proportional. (B) The The different characteristics of solids, liquids and gases result from. As a result, if we look at a plot of shear stress versus shear rate (See Figure 1) ( Shear Thinning or Thickening) or the deformation history (Thixotropic fluids). In contrast to Newtonian fluids, non-Newtonian fluids display either a non-linear relation it is the segregation of the different phases in the flow that causes a shear.
Cartoon showing the molecular difference between solids, liquids and gases. Definition of Fluid[ edit ] Fluid in motion: Itaipu Dam Fluid Mechanics is the study of fluids at rest fluid statics and in motion fluid dynamics. A fluid is defined as a substance that continually deforms flows under an applied shear stress regardless of the magnitude of the applied stress.
Fluid Mechanics for Mechanical Engineers/Introduction
Whereas a solid can resist an applied force by static deformation. Deformation of a solid and a fluid exposed to an applied force Liquidsgasesplasmas and, to some extent, plastic solids are accepted to be fluids. A perfect fluid offers no internal resistance to change in shape and, consequently, they take on the shape of their containers.
Liquids form a free surface that is, a surface not created by their container whereas gases and plasmas do not, but, instead, they expand and occupy the entire volume of the container. Behavior of liquids, gases and plasmas in a container Motivation for studying fluid mechanics[ edit ] Hurricane Katrina August 28 NASA The importance of flow phenomena is out of question.
Non-Newtonian fluid - Wikipedia
Natural phenomena or technological applications are completely or partially involves flow phenomena. It can be met in a diverse range of length of time scales.
Atmospheric flows and blood flows are two examples for this diversity. Applying force to Oobleck, by sound waves in this case, makes the non-Newtonian fluid thicken. Seuss book Bartholomew and the Oobleck.
A person may walk on a large tub of oobleck without sinking due to its shear thickening properties, as long as the individual moves quickly enough to provide enough force with each step to cause the thickening. Also, if Oobleck is placed on a large subwoofer driven at a sufficiently high volume, it will thicken and form standing waves in response to low frequency sound waves from the speaker. If a person were to punch or hit oobleck, it would thicken and act like a solid.
After the blow, the oobleck will go back to its thin liquid like state. Flubber material Flubber, also commonly known as slime, is a non-Newtonian fluid, easily made from polyvinyl alcohol —based glues such as white "school" glue and borax. It flows under low stresses but breaks under higher stresses and pressures.
- Non-Newtonian fluid
This combination of fluid-like and solid-like properties makes it a Maxwell fluid. Its behaviour can also be described as being viscoplastic or gelatinous. The sudden application of force —by stabbing the surface with a finger, for example, or rapidly inverting the container holding it—causes the fluid to behave like a solid rather than a liquid.