Boundary Layer Flow 12 - Blasius Solutions for Flow over a Flat Plate

Question 1

Conditions for the Blasius problem

Answer 1

Flat and infinitely long plate submerged in uniform free stream with zero angle of attack
BL flow is laminar, steady and incompressible
Since free stream flow is uniform, there is zero pressure gradient

Question 2

What is an ordinary differential equation?

Answer 2

Differential equation containing only one independent variable

Question 3

Physical interpretation of Blasius solution

Answer 3

Assumptions - infinitely long plate, uniform free stream velocity
No reason for any specific location to be different from others, except for BL thickness changes
Local velocity profiles at any location x should all have the same profile (self-similar) - u=u(x,y) at different x can be made identical by selecting suitable scaling factors for u and y

Question 4

What is skin friction caused by?

Answer 4

Viscous stress at the wall

Question 5

Relationships of boundary layer thickness

Answer 5

Inversely proportional to root of free stream velocity
Directly proportional to root of x