### Private: Basics of Fluid Dynamics

Certification Exam

# Theory-based Quiz

#### Total number of Questions - 45

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Basics of Fluid Dynamics ITC

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1 / 44

For a fluid flow to be considered a steady flow, it must be:

2 / 44

Brinkman Number is defined as the ratio of

3 / 44

Which of the following are examples of internal flows?

4 / 44

An altimeter uses _______ to measure altitude.

5 / 44

A system can be considered as an open system when :

6 / 44

Which of the following is true about Taylor number ($Ta$)?

7 / 44

Which of the following statements are true for irrotational flows?

8 / 44

The dynamic viscosity for a non-newtonian fluid is a function of which of the following?

9 / 44

Which of the following is an example of 'internal flow'?

10 / 44

An isothermal incompressible fluid flows through a perfectly insulated coiled tube. To describe the problem, how many unknowns need to be solved for from the system of equations ?

11 / 44

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

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

12 / 44

Using the Stokes' approximation, you were asked to calculate the non-dimensional drag coefficient for a creeping flow around a cylinder (under 2D assumptions). What do you find out?

13 / 44

When comparing with experiments, the validity range of Oseen's approximation for low Reynolds number flows was found to be _____

14 / 44

The sensor connected to the pitot tube on a racing car is sending a record of increasing total pressure values, while the static pressure is constant. This means that the car is

15 / 44

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

16 / 44

Which of the following is caused by the surface tension of a fluid?

17 / 44

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

18 / 44

What does the Reynolds Number physically represent?

19 / 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.

20 / 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:

21 / 44

The liquid in a manometer is at the same height on both the tubes. This means that:

22 / 44

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

23 / 44

What are the basic elements of a mathematical model of a fluid dynamics problem?

24 / 44

Which of these statements is true about 2D planar simplification?

25 / 44

Which of the following is a non-intrusive (i.e. the measurement process does not disturb the flow) method of measuring temperature?

26 / 44

The following measurement technique is applicable for measuring velocity :

27 / 44

Given basic dimensions of mass $M$, length $L$ and time $T$, what would be dimensions of Energy/Work:

28 / 44

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

29 / 44

Which of the following is the correct expression for skin friction coefficient for laminar flows in round pipes? ($Re_{D}=\frac{\rho \bar{u}D}{\mu}$)

30 / 44

What is the definition of the Knudsen number?

31 / 44

$1/5^{th}$ model of car is tested in a wind tunnel. For the flow over the test model to be dynamically similar to that of the full-scale car, the wind tunnel velocity for the model must be: [Hint: both the model and full-scale car are being tested in the same wind-tunnel].

32 / 44

Which of the following represents the Fourier's Law? ($k$ is the thermal conductivity of the fluid)

33 / 44

The fundamental physical dimensions used in fluid dynamics are:

34 / 44

Given the fluid velocity field $\overline{V}$, Which of the following is the correct expression for vorticity?

35 / 44

Consider a body moving through a viscous fluid. The magnitude of the normal component of the viscous stress acting on the body surface is:

36 / 44

Consider a hot air balloon up in the air that is subject to neutral buoyancy. The weight of the balloon structure cannot be neglected.

The balloon can drop altitude if :

37 / 44

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

38 / 44

Poiseuille (pipe) flows are laminar for:

39 / 44

In which of the following cases does pressure drag dominate compared to the viscous drag?

40 / 44

Which fundamental law of physics is the foundation for the conservation of momentum?

41 / 44

The fluid flow over which of the following cases can be considered as a supersonic flow?

42 / 44

Consider the barometer shown in the picture. If the atmospheric pressure decreases, then the height $h$:

43 / 44

The velocity profile corresponding to an axisymmetric fully developed flow in a round pipe (Axisymmetric Hagen-Poiseuille Flow) is

44 / 44

Two different incompressible laminar fluid flows - $A$ and $B$, through identical venturi tubes such that the pressure drop across the two venturi tubes is the same for both the fluids. If we know that the density of fluid $B$ ($\rho_B$) is four times that of fluid $A$ ($\rho_A$), then which of the following statements is true?