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. |
What is the relation between the E of the E-factor relaxation and the relaxation factor λ? |
| A. | E=\(\frac{1}{1-\lambda}\) |
| B. | E=\(\frac{\lambda}{1-\lambda}\) |
| C. | E=\(\frac{\lambda}{1+\lambda}\) |
| D. | E=\(\frac{1}{1+\lambda}\) |
| Answer» B. E=\(\frac{\lambda}{1-\lambda}\) | |
| 2. |
The time-step advancement of the E-factor relaxation is dependent on ___________ |
| A. | the convergence |
| B. | the stability |
| C. | the accuracy |
| D. | the cell volume |
| Answer» E. | |
| 3. |
Which of these statements about the Patankar’s under-relaxation is true? |
| A. | The value form the previous iteration is modified |
| B. | The diagonal coefficients are modified |
| C. | The whole equation is modified |
| D. | The neighbouring coefficient is modified |
| Answer» C. The whole equation is modified | |
| 4. |
Which of these relaxation techniques is used in the SIMPLE algorithm? |
| A. | Explicit over-relaxation |
| B. | Implicit over-relaxation |
| C. | Explicit under-relaxation |
| D. | Implicit under-relaxation |
| Answer» D. Implicit under-relaxation | |
| 5. |
What is the disadvantage of over-relaxation? |
| A. | Stability is decreased |
| B. | Divergence is increased |
| C. | Oscillations are increased |
| D. | Convergence is increased |
| Answer» B. Divergence is increased | |
| 6. |
There is no relaxation when the relaxation factor is __________ |
| A. | positive infinity |
| B. | negative infinity |
| C. | one |
| D. | zero |
| Answer» E. | |
| 7. |
When the relaxation factor is less than one, which of these will occur? |
| A. | Increase the speed of convergence |
| B. | Slow down the speed of convergence |
| C. | Decrease the stability |
| D. | Increase the divergence |
| Answer» C. Decrease the stability | |
| 8. |
The explicit under-relaxation method means that __________ |
| A. | the changes are made before each iteration |
| B. | the changes are made before the iteration process |
| C. | the changes are made after the iteration process |
| D. | the changes are made after each iteration |
| Answer» D. the changes are made after each iteration | |
| 9. |
The relaxation techniques slow down the __________ |
| A. | whole iterative process |
| B. | effect of the sources |
| C. | effect of the neighbouring elements and the source terms |
| D. | effect of the neighbouring elements |
| Answer» D. effect of the neighbouring elements | |
| 10. |
Relaxation techniques are used to ensure __________ |
| A. | convergence |
| B. | stability |
| C. | accuracy |
| D. | boundedness |
| Answer» B. stability | |