MCQOPTIONS
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MCQOPTIONS
This section includes 10 Mcqs, each offering curated multiple-choice questions to sharpen your Computational Fluid Dynamics knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Numerical dispersion is a result of __________ |
| A. | higher-order interpolation profile |
| B. | unphysical behaviour of assumed interpolation profile |
| C. | first-order interpolation profile |
| D. | quadratic interpolation profile |
| Answer» C. first-order interpolation profile | |
| 2. |
What is the problem of numerical diffusivity? |
| A. | The simulated model has a higher diffusivity than the actual flow |
| B. | The simulated model has a lower diffusivity than the actual flow |
| C. | The simulated model has a different diffusivity than the actual flow |
| D. | The simulated model has a zero diffusivity |
| Answer» B. The simulated model has a lower diffusivity than the actual flow | |
| 3. |
Which of these is correct for the central difference scheme? |
| A. | Neither numerical dispersion nor numerical diffusion error arises |
| B. | Only numerical diffusion error arises |
| C. | Both numerical dispersion and numerical diffusion errors arise |
| D. | Only numerical dispersion error arises |
| Answer» E. | |
| 4. |
Which is correct regarding the upwind scheme? |
| A. | Neither numerical dispersion nor numerical diffusion error arises |
| B. | Only numerical diffusion error arises |
| C. | Both numerical dispersion and numerical diffusion errors arise |
| D. | Only numerical dispersion error arises |
| Answer» D. Only numerical dispersion error arises | |
| 5. |
Which of these methods can be used to evaluate the errors in convection-diffusion schemes? |
| A. | Using the exact solution of the source-free problem |
| B. | Using the exact solution of the source and diffusion-free problem |
| C. | Using the exact solution of the diffusion-free problem |
| D. | Using the first-order schemes |
| Answer» C. Using the exact solution of the diffusion-free problem | |
| 6. |
Numerical dispersion error causes __________ |
| A. | convergence problems |
| B. | accuracy problems |
| C. | boundedness problems |
| D. | stability problems |
| Answer» D. stability problems | |
| 7. |
Which of these methods cannot be used to reduce the errors due to cross-stream numerical diffusion? |
| A. | Interpolation in the direction of flow |
| B. | Higher order interpolation profile |
| C. | Multi-dimensional interpolation profiles |
| D. | Changing the direction of interpolation |
| Answer» E. | |
| 8. |
What is the cause of cross-stream numerical diffusion? |
| A. | One-dimensional nature of the assumed profiles |
| B. | Multi-dimensional nature of the assumed profiles |
| C. | Higher order of accuracy |
| D. | Higher order of interpolation |
| Answer» B. Multi-dimensional nature of the assumed profiles | |
| 9. |
Which of these ways can be used to overcome stream-wise numerical diffusion? |
| A. | Decreasing the order of interpolation |
| B. | Increasing the order of interpolation |
| C. | Increasing the number of neighbours considered |
| D. | Decreasing the number of neighbours considered |
| Answer» C. Increasing the number of neighbours considered | |
| 10. |
Numerical diffusion causes __________ |
| A. | smearing of sharp gradients |
| B. | oscillations |
| C. | undershoots and overshoots |
| D. | inaccuracy |
| Answer» B. oscillations | |