h&f lecture 3

Question 1

What forces act on the CV to allow us to apply the momentum equation?

Answer 1

Body forces ( gravitational, magnetic)

Surface Forces ( act on the CV)

Question 2

What are the two catagories of surface force?

Answer 2

Pressure force (due to presence of surrounding fluid: always acts inward)

surface forces ( shear and normal stresses pushing and tugging)

Question 3

what type of diffusion occurs and what direction is it in when shear stresses are present on a 2D body?

Answer 3

diffusion of momentum in the high to low shear direction (look for terms du/dy, dv/dx etc)

Question 4

when normal stress occurs, on a 2D body, which stress is greater? sigma1 or sigma2?

Answer 4

sigma 2

Question 5

what does the term u * du/dx represent?

Answer 5

convection of u in x-direction

Question 6

what does the term v * du/dy represent?

Answer 6

convection of u in the y-direction

Question 7

what does the term u/p (d^2u/dx^2) represent?

Answer 7

diffusion of u in the x direction due to normal stresses for constant velocity

Question 8

what does the term u/p(d^2u/dy^2) represent?

Answer 8

diffusion of u in the y-direction due to shear stresses for constant velocity