# Theory-based Quiz

#### Total number of Questions - 45

Times up!

Real Viscous Flows

If you get stuck, you can skip the current question and navigate between the different questions by using the "Previous" and "Next" buttons.

Once you have finished the exam, click on the 'Mark Complete' button to save your progress and move to the next section.

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:

4 / 45

5 / 45

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?

12 / 45

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

13 / 45

Which of the following are examples of rotating devices?

14 / 45

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

15 / 45

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

16 / 45

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:

18 / 45

Which of the following statements are true regarding turbulent flows?

19 / 45

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?

23 / 45

In the viscous sublayer of a turbulent boundary layer:

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?

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

33 / 45

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

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?

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:

40 / 45

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

41 / 45

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?
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