### Private: Basics of Fluid Dynamics

Certification Exam

# Theory-based Quiz

#### Total number of Questions - 45

Times up!

Basics of Fluid Dynamics ITC

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 / 44

In the case of Couette flow between two moving plates, the distribution of shear stress inside the fluid is:

2 / 44

A massless particle in an unsteady flow is tracked from an initial position at ($x_0$,$y_0$,$z_0$) at $t=t_0$ to a second position at ($x_1$,$y_1$,$z_1$) at $t=t_1$. The curve traced out by the particle is referred to as a ________.

3 / 44

We wish to use CFD to model the air flow around a car. The car is travelling north at a speed of $60$ $mph$. The wind is blowing south with wind speeds of $10$ $mph$. What inlet boundary velocity value should be used?

4 / 44

Brinkman Number is defined as the ratio of

5 / 44

Which of the following flow visualization technique is useful for observing shock waves in supersonic flows?

6 / 44

Which of the following statements are true regarding the "specific gravity"?

7 / 44

When a force is applied to both a solid and fluid, which of the following is true?

8 / 44

What is the expression of the pressure force component of surface forces in terms of surface integrals?

9 / 44

Consider the barometer shown in the picture. In order to maintain the same height $h$ for the same atmospheric pressure, on a planet with twice the gravitational acceleration, we could:

10 / 44

Consider the manometer shown in the picture. The pressure difference $\Delta p$ is equal to:

11 / 44

For a potential flow past a circular cylinder, which of the following conditions is referred to as the D'Alembert's paradox?

12 / 44

The peak of Mount Everest is at an altitude of $8.84$ $km$ above sea level. To reach the summit, climbers trek through the Everest base camp, which is at an altitude of $5.4$ $km$ above the sea level. Assuming an isothermal atmosphere (temperature, $T$), what is the ratio of atmospheric pressures at the summit to that of the base camp.

13 / 44

An american football is flying horizontally in air. The plot shows the pressure contours of the ball moving from right to left. Which region has the lowest pressure?

14 / 44

In the case of 2D Poiseuille flow in a 2D planar channel, the maximum velocity occurs at:

15 / 44

A system can be considered as an open system when :

16 / 44

The fundamental physical dimensions used in fluid dynamics are:

17 / 44

What is a reasonable simplifying modeling assumption for air at standard temperature and pressure flowing over a uniform wing section of an aircraft?

18 / 44

When a fluid is at rest, the total gravitational force exerts a ________ force on any surrounding surfaces as a result of _____________.

19 / 44

Fluid statics can be used for ______

20 / 44

Consider steady laminar axisymmetric flow of a viscous fluid between two long concentric cylinders where the inner cylinder of radius $R_{i}$ is stationary while the outer cylinder of radius $R_{o}$ moves about the axis at $U$. Assuming the viscosity of the fluid to be $\mu$, the velocity can be expressed as:

21 / 44

What are two reasonable simplifying modeling assumptions for a laminar jet flow from a circular nozzle?

22 / 44

What is the correct value of Poiseuille number for laminar flows in round pipes?

23 / 44

What is the missing factor (?) in the non-dimensional form of the incompressible x-momentum equation? Equation is below:

$\rho^\ast\left[\frac{\partial u^\ast}{\partial t^\ast}+\mathrm{\nabla}\bullet\left({\vec{V}}^\ast u^\ast\right)\right]=-\frac{\partial p^\ast}{\partial x^\ast}+{(?)\mathrm{\nabla}}^2u^\ast$

24 / 44

In a pitot tube mounted on an aircraft, what is the difference between the total and static pressures inside the total pressure tube?

25 / 44

Consider an aircraft flying horizontally at an altitude of $8\ km$ with a speed of $250\ m/s$. The drag force is ______ with respect to the direction of motion of the aircraft.

26 / 44

The maximum velocity in an axisymmetric fully developed flow in a round pipe (radius = $R$) (Axisymmetric Hagen-Poiseuille Flow) occurs at ($r$= radial distance from the centerline):

27 / 44

In a vertical circular water pipe $3\ m$ long with constant diameter ($D = 1\ cm$), water is flowing from inlet (bottom) to outlet (top), in a direction opposite to the gravitational force. The static pressure at the inlet is $101\ kPa$ and inlet velocity is $0.001\ m/s$. Assuming water as an incompressible fluid, the static pressure at the outlet:

28 / 44

Which of the following statements are true in the context of an aircraft stall?

29 / 44

Which of the following statements are true about the operation of the venturi tube :

30 / 44

What does the Reynolds Number physically represent?

31 / 44

The definition of an incompressible flow is: a fluid flow that always has a constant ________ .

32 / 44

An airplane is traveling at a Mach Number = $2$. This means the airplane is traveling at the speed which is _______ times the local speed of sound.

33 / 44

Which of the following is true when the velocity is a function of time?

34 / 44

Which of the following are examples for external flows?

35 / 44

In which of the following examples is it important to consider gravitational forces acting on the fluid?

36 / 44

What is the integral form of the body force due to the gravitational acceleration?

37 / 44

Which of the following equations represents the conversation of mass equation under the incompressible flow assumption?

38 / 44

What’s an example of a solid behaving like a fluid?

39 / 44

In the case of Couette flow between two moving plates, the velocity profile is:

40 / 44

The mean velocity for an axisymmetric fully developed flow in a round pipe (Axisymmetric Hagen-Poiseuille Flow) is:

41 / 44

Which of the following terms represent the unsteady, time varying behavior of the conversation of mass equation?

42 / 44

On this symmetric airfoil with $0$ angle of attack, where is the point of highest pressure located? Please see the image below as reference.

43 / 44

The phase of a substance depends on :