Section 3 - practice problems - Concept Review 9-1C The divergence theorem is where is a vector, V

the divergence theorem in words.

9-3C What does it mean when we say that two or more differential equations are coupled?

9-4C For a three-dimensional, unsteady, incompressible flow field in which temperature variations are insignificant, how many unknowns are there? List the equations required to solve for these unknowns.

9-5C For an unsteady, compressible flow field that is two-dimensional in the x-y plane and in which temperature and density variations are significant, how many unknowns are there? List the equations required to solve for these unknowns. (Note: Assume other flow properties like viscosity, thermal conductivity, etc., can be treated as constants.)

9-6C For an unsteady, incompressible flow field that is two-dimensional in the x-y plane and in which temperature variations are insignificant, how many unknowns are there? List the equations required to solve for these unknowns

9-22C If a flow field is compressible, what can we say about the material derivative of density? What about if the flow field is incompressible?

9-28 Consider the steady, two-dimensional velocity field given by = (u, v) = (1 + 1) + (1 − 1. 8 y)

. Verify that this flow field is incompressible.

9-35 The u velocity component of a steady, two-dimensional, incompressible flow field is u = 3ax 2 − 2 bxy, where a and b are constants. Velocity component v is unknown. Generate an expression for v as a function of x and y.

Concept Review

9-1C The divergence theorem is

where is a vector, V is a volume, and A is the surface area that encloses and defines the volume. Express

the divergence theorem in words.

9-3C What does it mean when we say that two or more differential equations are coupled?

9-4C For a three-dimensional, unsteady, incompressible flow field in which temperature variations are

insignificant, how many unknowns are there? List the equations required to solve for these unknowns.

9-5C For an unsteady, compressible flow field that is two-dimensional in the x-y plane and in which

temperature and density variations are significant, how many unknowns are there? List the equations

required to solve for these unknowns. (Note: Assume other flow properties like viscosity, thermal

conductivity, etc., can be treated as constants.)

9-6C For an unsteady, incompressible flow field that is two-dimensional in the x-y plane and in which

temperature variations are insignificant, how many unknowns are there? List the equations required to

solve for these unknowns

9-22C If a flow field is compressible, what can we say about the material derivative of density? What

about if the flow field is incompressible?

Section 3 - practice problems

Introduktion til vindenergi (46000)

Danmarks Tekniske Universitet

Anbefalet til dig

Kommentarer

Studerende så også

Andre relaterede dokumenter

Forhåndsvisning af tekst

Concept Review

9-1C The divergence theorem is

where is a vector, V is a volume, and A is the surface area that encloses and defines the volume. Express

the divergence theorem in words.

9-93 Repeat Example 9-17, except for the case in which the wall is inclined at angle α (Fig. P9-93).

agrees with that of Example 9-17 when α = 90°. [Hint: It is most convenient to use the (s, y, n) coordinate

system with velocity components (us, v, un), where y is into the page in Fig. P9-93. Plot the dimensionless