Master CFD Basics: A Comprehensive Guide for Beginners

Question 1

Which numerical method is most commonly used in CFD?

Accepted Answer

Finite volume method

Answer

Finite difference method

Answer

Finite element method

Answer

Boundary element method

Question 2

What is the purpose of turbulence models in CFD?

Accepted Answer

Predicting turbulent flow behavior

Answer

Simplifying governing equations

Answer

Improving CFD solution accuracy

Answer

Reducing computational costs

Question 3

Which numerical method is most commonly used in CFD to solve the governing equations?

Accepted Answer

Finite volume method

Answer

Finite element method

Answer

Boundary element method

Answer

Spectral method

Question 4

What type of boundary condition is used to specify the flow velocity at a boundary where the fluid enters the domain?

Accepted Answer

Dirichlet boundary condition

Answer

Neumann boundary condition

Answer

Cauchy boundary condition

Answer

Periodic boundary condition

Question 5

Which software package is widely used for commercial CFD simulations?

Accepted Answer

ANSYS Fluent

Answer

COMSOL Multiphysics

Answer

OpenFOAM

Answer

MATLAB

Question 6

Specify the type of boundary condition that prescribes the flow velocity at a boundary.

Accepted Answer

Dirichlet Boundary Condition

Answer

Neumann Boundary Condition

Answer

Mixed Boundary Condition

Answer

Periodic Boundary Condition

Question 7

What is the primary purpose of a boundary condition in CFD?

Accepted Answer

To define the physical behavior at the boundaries of the computational domain

Answer

To solve the governing equations more efficiently

Answer

To improve the accuracy of the solution

Answer

To reduce computational time

Question 8

Which numerical method is commonly used in CFD due to its conservation properties?

Accepted Answer

Finite volume method

Answer

Finite element method

Answer

Boundary integral method

Answer

Lattice Boltzmann method

Question 9

What is a key advantage of using CFD over experimental methods in fluid mechanics?

Accepted Answer

Ability to simulate complex geometries

Answer

Lower cost

Answer

Faster results

Answer

Higher accuracy

Question 10

Which condition is used in CFD to ensure numerical stability?

Accepted Answer

Courant-Friedrichs-Lewy (CFL) condition

Answer

Maximum allowable time step size

Answer

Convergence criteria

Answer

Accuracy requirements

Question 11

In CFD, what is the difference between Dirichlet and Neumann boundary conditions?

Accepted Answer

Dirichlet: Prescribes the value; Neumann: Prescribes the gradient

Answer

Dirichlet: Prescribes the gradient; Neumann: Prescribes the value

Answer

Both prescribe the flow velocity

Answer

Both prescribe the pressure

Question 12

In the momentum equation for incompressible flow, what is the physical meaning of the pressure gradient term?

Accepted Answer

It represents the force per unit volume acting on the fluid due to a pressure difference.

Answer

It measures the pressure change over a distance.

Answer

It is only significant in compressible flows.

Question 13

What is the primary purpose of a computational mesh in CFD?

Accepted Answer

To discretize the computational domain

Answer

To visualize the flow field

Answer

To solve the governing equations directly

Answer

To apply boundary conditions

Question 14

Which boundary condition is employed to specify the velocity at a solid wall?

Accepted Answer

No-slip boundary condition

Answer

Slip boundary condition

Answer

Far-field boundary condition

Answer

Pressure boundary condition

Question 15

What is a key advantage of using CFD for fluid flow analysis?

Accepted Answer

CFD can solve complex flow problems that are difficult or impossible to solve analytically.

Answer

CFD is inherently more accurate than experimental methods

Answer

CFD is always faster than experimental methods

Question 16

Which of the following is not a factor that can influence the accuracy of CFD simulations?

Accepted Answer

Experience of the user

Answer

Numerical scheme

Answer

Boundary conditions

Answer

Computational mesh quality

Question 17

Describe the fundamental difference between explicit and implicit numerical schemes in CFD.

Accepted Answer

Explicit schemes solve the equations at each time step independently, while implicit schemes solve the equations simultaneously.

Answer

Explicit schemes are invariably more accurate than implicit schemes

Question 18

Which flow regime is characterized by low Reynolds numbers, resulting in dominant viscous effects?

Accepted Answer

Laminar flow

Answer

Compressible flow

Answer

Supersonic flow

Answer

Turbulent flow

Question 19

What is the primary purpose of using a turbulence model in CFD simulations?

Accepted Answer

To account for the effects of turbulence on the flow field and enhance the accuracy of the simulation.

Answer

To reduce the computational cost

Answer

To simplify the governing equations

Question 20

Which software is commonly used for CFD simulations?

Accepted Answer

ANSYS Fluent

Answer

Excel

Answer

SolidWorks

Answer

MATLAB

Question 21

What is the fundamental distinction between CFD and experimental fluid dynamics?

Accepted Answer

CFD employs numerical methods to solve governing equations while experimental fluid dynamics relies on physical experiments and measurements.

Answer

CFD is more expensive than experimental fluid dynamics