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Real Viscous Flows

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1 / 45

Which of the following equations is referred to as the ideal gas equation of state

2 / 45

The Falkner-Skan similarity solution can be applied to analyze which of the following cases?

3 / 45

The Blasius solution for laminar boundary layers can be used for:

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The cascade of energy from large to small eddies leads to:

(Select the two correct answers.)

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When a viscous fluid flows with a uniform velocity over a flat plate, a boundary layer starts forming at the leading edge and its thickness continues to _____________ along the length of the plate.

6 / 45

For a supersonic flow over 2d wedge as shown in the figure, the shock waves formed can be categorized as

7 / 45

Consider the Blasius boundary layer equation for a flat plate shown here below.

$f^{'''}+\frac{1}{2}ff^{''}=0$

To solve the equation we need the following boundary conditions:

$f (\eta=0)=0$

$f^{'} (\eta=0)=0$

$f^{'} (\eta \rightarrow \infty)=1$

The third of these boundary conditions indicates that:

8 / 45

Consider the Moody diagram where friction factor varies with flow Reynolds number. The information on the axes has been removed, and four regions have been marked ($3$ and $4$ are divided by the red dashed line). Based on this plot, which region identifies the laminar regime?

9 / 45

In the Moody diagram, for Reynolds numbers past the Complete Turbulence line, we can assume that:

10 / 45

By definition, the drag force generated by a flow over a body acts:

11 / 45

Which of the following state variables are introduced using the second law of thermodynamics?

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Which of the following statements are true regarding the characteristics of turbulence?

(Select the two correct answers.)

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Which of the following are examples of rotating devices?

(Select the two correct answers.)

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Using the Boussinesq approximation to close the RANS equations leads to reducing the $9$ unknowns to:

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The minor losses at the entrance of a pipe, especially due to a sharp turn at the corner, are due to:

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Which of the following is true for an irreversible process according to the 2nd law of thermodynamics?

17 / 45

Analytical solutions can be obtained for external flows over:

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Which of the following statements are true regarding turbulent flows?

(Select the three correct answers.)

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For a straight leveled pipe the head loss is caused by:

20 / 45

Which of the following equations is used to calculate the Lift coefficient, $C_L$?

21 / 45

Based on area and wetted perimeter, hydraulic diameter for internal flows is defined as _______

22 / 45

Which of the following are associated with stall of an aircraft wing?

(Select the three correct answers.)

23 / 45

In the viscous sublayer of a turbulent boundary layer:

(Select the two correct answers.)

24 / 45

In an internal flow, which of the following is the correct mathematical definition of the $K$-factor?

25 / 45

In case of laminar mixing layer, after a self-similar profile is reached, which of the following conditions is satisified at the interface between the two fluids?

(Select the two correct answers.)

26 / 45

The only mode of heat transfer occuring in vaccuum is:

27 / 45

A mixing layer is formed when

28 / 45

For a symmetric airfoil such as NACA 0012, before the stall AoA, the relationship between lift coefficient and angle of attack is

29 / 45

When a flow network in a fluid system is represented using the electrical network analogy, the total voltage potential (between the inlet and outlet) in the electrical network is analogous to:

30 / 45

For an inertially dominant flow, based on Prandtl's boundary layer theory, the effect of the viscosity is ________

31 / 45

If the flow through a turbomachine is perpendiculat to the axis of rotation, then we can say that the apparatus is:

32 / 45

Adverse pressure gradient refers to a situation where

33 / 45

The parameters affecting the friction coefficient for a flow over the flat plate are:

(Select the three correct answers)

34 / 45

Consider a turbulent boundary layer. In the picture below, three vertical dashed lines divide the plot into four regions. In which of the regions would the buffer layer be located?

35 / 45

According to the 1st law of thermodynamics, the difference of the heat transfer into the system and the work done by the system is equal to the change of ______

36 / 45

For a turbulent boundary layer, what is the extent of the laminar sublayer in terms of the non-dimensional distance from the wall ($y^+$) ?

37 / 45

Which of the following are examples of Internal flows?

(select the three correct answers.)

38 / 45

In order to close the RANS equations ______ need to be modeled.

39 / 45

The inner layer of a turbulent boundary layer does NOT depend on:

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Consider the classical two-dimensional laminar boundary layer equations for a fluid at a large $Re$. The Y-momentum equation states that:

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In a laminar boundary layer flow over a flat plate, the relationship between the hydrodynamic boundary layer thickness and Reynolds number along the length of the plate is given by:

42 / 45

The wall shear stress exerted by a flow over any body acts:

43 / 45

Which of the following factors can help in reattachment of separated laminar flow?

(Select the two correct answers.)

44 / 45

The following statements are true regarding the field of thermodynamics.

(Select the two correct answers.)

45 / 45

For a round pipe, if the flow is turbulent, the entrance length can be estimated as _____, where $D$ is the diameter of the pipe and $Re$ is the Reynolds number of the flow based on the diameter

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