The fluid flow in Newtonian theory is modelled as which of the following?

Wave

Stream of particles in conic section

Stream of particles in rectilinear motion

Particles moving in a random direction

Correct Answer : Stream of particles in rectilinear motion

Explanation : Newton formulated the Newtonian theory by modeling the fluid flow as a stream of particles that move in a rectilinear motion. The individual particles of the flow stream do not move in a random direction. The particles lose the momentum normal to the surface once it strikes. Its tangential momentum is retained without any loss.

Recently Updated in Aerodynamics Questions

Which of these laws is used to find the heat flux at a point in the fluid?

Fourier law

Fick�s law

Kepler�s law

Newton�s law

Correct Answer : Option (A) : Fourier law

Explanation : Fourier law which is also known as the law of heat conduction is used to find out the heat flux at any point in the fluid. It is given by the formula:

Where, heat flux is in the y – direction
Minus sign indicates that the heat flows from high temperature to low temperature and thus q?_y is in opposite direction to the temperature gradient.

What happens to the shear stress if the thickness between the two plates is increased in a Couette flow?

Increases

Decreases

Remains same

Becomes infinite

Correct Answer : Option (B) : Decreases

Which of these laws is obeyed by a Newtonian fluid?

Prandtl law

Newtonian law

Shear stress law

Incompressible fluid law

Correct Answer : Option (C) : Shear stress law

Explanation : Newtonian fluids are characterized by those fluids that obey the shear stress law. Aeronautics domain makes use of newtonian fluids only (air, other gases). Those fluids that don’t obey shear stress law are known as non – newtonian fluids (blood).