Computational Fluid Dynamics Practice Test 1

1. Which is the input part of a CFD problem?

Pre-processing

Solving

Post-processing

Flow visualization

2. Let,
V → Control Volume
B → Flow property
b → Intensive value of B in any small element of the fluid
ρ → Density of the flow
t → Instantaneous time
Which of these terms represent the ‘instantaneous total change of the flow property within the control volume’ after Leibniz rule is applied?

\( \int_v \frac{\partial}{\partial T}(b \rho)dV\)

\(\rho \int_v \frac{\partial b}{\partial T} dV \)

\(\rho \int_v \frac{\partial \rho}{\partial b} dV\)

\( \frac{d}{dt}(\int_vb \rho dV)\)

3. CFD packages solve the algebraic equations of flow using ____________ method.

Direct

Trial and error

Analytical

Iterative

4. Other than finite control volume and infinitesimal small element, what is the third possible modelling of fluid flow?

Discrete approach

Macroscopic approaches

Quantum approach

Microscopic approach

5. Computational fluid dynamic results are _________ wind tunnel results.

Energy consuming when compared to

Better than

Analogous to

More reliable than

6. Which one do you think is not possible with wind tunnels for testing trans-atmospheric vehicles?

Hypersonic flows

Simultaneously modelling high Mach numbers and high temperatures

Continuously changing Mach number

Transonic flows

7. Which of these will best define positions of the parcel in increasing time?

Pathline

Boundary line

Streakline

Streamline

8. ____________ of a mathematical model is a limitation to CFD.

Validity

Solvability

Reliability

Accuracy

9. Aerodynamics engineers obtain the lift and pressure drag by integrating the ___________ distribution over a surface.

Velocity

Viscosity

Temperature

Pressure

10. Energy conservation equation is necessary to solve this property of fluid flow.

Temperature

Density

Velocity

Pressure