Fluid is a substance which is capable of flowing OR Fluid is substance which deforms continuously under the influence of a shear or tangential force. OR The tendency to deform continuously is called fluidity and act of continuous deformation is called as flow.
Classification of fluids-
|Ideal Fluid||Real Fluid|
|Fluids which don’t have viscosity and are incompressible are termed as ideal fluid such fluid do not offer shear resistance.||Fluids which do posses viscosity are termed as real fluids. These fluids always offer shear resistance.|
Real Fluid further classified into two types
Newtonian fluid- The fluids which obey Newton’s law of viscosity are called as Newtonian fluids such fluids exhibit linear relationship between shear stress and rate of angular deformation. Eg. - water , air etc.
Non-Newtonian Fluid- Fluids which do not follow the linear relation between shear stress and rate of angular deformation are termed as Non Newtonian fluids. Hence for such fluids;