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. |
When the flow is not aligned with the grid lines, the diffusion produced by the upwind scheme is ____________ |
| A. | false advection |
| B. | false convection |
| C. | anti-diffusion |
| D. | false diffusion |
| Answer» D. false diffusion | |
| 2. |
The upwind scheme is _____________ |
| A. | conservative but wiggles |
| B. | bounded and conservative |
| C. | bounded but not conservative |
| D. | neither conservative nor bounded |
| Answer» C. bounded but not conservative | |
| 3. |
The advantage of the upwind scheme is over the central-difference scheme is _____________ |
| A. | accuracy |
| B. | stability |
| C. | high convergence rate |
| D. | consistency |
| Answer» B. stability | |
| 4. |
Consider the stencil. Give the advection flux at face w \((\dot{m_w}\phi_W)\) using the downwind scheme.(Note: \(\dot{m}\) and Φ are the mass flow rate and the flow variable respectively). |
| A. | \(\dot{m_w}\phi_W = -max(\dot{m_w},0)\phi_C+max(\dot{m_w},0)\phi_W\) |
| B. | \(\dot{m_w}\phi_W = max(\dot{m_w},0)\phi_C+max(\dot{m_w},0)\phi_W\) |
| C. | \(\dot{m_w}\phi_W = -max(-\dot{m_w},0)\phi_C+max(\dot{m_w},0)\phi_W\) |
| D. | \(\dot{m_w}\phi_W = max(-\dot{m_w},0)\phi_C+max(\dot{m_w},0)\phi_W\) |
| Answer» D. \(\dot{m_w}\phi_W = max(-\dot{m_w},0)\phi_C+max(\dot{m_w},0)\phi_W\) | |
| 5. |
The order of accuracy of the upwind scheme is _____________ |
| A. | first-order |
| B. | second-order |
| C. | third-order |
| D. | fourth-order |
| Answer» B. second-order | |
| 6. |
Consider the following stencil. Give the relationship between \(\frac{\phi_C-\phi_W}{\phi_E-\phi_W}\) and Peclet number (Pe) for the upwind scheme while used for the convection term.(Note: Φ is the flow variable). |
| A. | \(\frac{\phi_C-\phi_W}{\phi_E-\phi_W} = \frac{2-max(Pe,0)}{4+\big|Pe\big|} \) |
| B. | \(\frac{\phi_C-\phi_W}{\phi_E-\phi_W} = \frac{2-max(-Pe,0)}{4+\big|Pe\big|} \) |
| C. | \(\frac{\phi_C-\phi_W}{\phi_E-\phi_W} = \frac{2+max(Pe,0)}{4+\big|Pe\big|} \) |
| D. | \(\frac{\phi_C-\phi_W}{\phi_E-\phi_W} = \frac{2+max(-Pe,0)}{4+\big|Pe\big|} \) |
| E. | for the upwind scheme while used for the convection term.(Note: Φ is the flow variable).a) \(\frac{\phi_C-\phi_W}{\phi_E-\phi_W} = \frac{2-max(Pe,0)}{4+\big|Pe\big|} \) b) \(\frac{\phi_C-\phi_W}{\phi_E-\phi_W} = \frac{2-max(-Pe,0)}{4+\big|Pe\big|} \) c) \(\frac{\phi_C-\phi_W}{\phi_E-\phi_W} = \frac{2+max(Pe,0)}{4+\big|Pe\big|} \) d) \(\frac{\phi_C-\phi_W}{\phi_E-\phi_W} = \frac{2+max(-Pe,0)}{4+\big|Pe\big|} \) |
| Answer» E. for the upwind scheme while used for the convection term.(Note: Φ is the flow variable).a) \(\frac{\phi_C-\phi_W}{\phi_E-\phi_W} = \frac{2-max(Pe,0)}{4+\big|Pe\big|} \) b) \(\frac{\phi_C-\phi_W}{\phi_E-\phi_W} = \frac{2-max(-Pe,0)}{4+\big|Pe\big|} \) c) \(\frac{\phi_C-\phi_W}{\phi_E-\phi_W} = \frac{2+max(Pe,0)}{4+\big|Pe\big|} \) d) \(\frac{\phi_C-\phi_W}{\phi_E-\phi_W} = \frac{2+max(-Pe,0)}{4+\big|Pe\big|} \) | |
| 7. |
The neighbour coefficients yielded by the upwind scheme for convection is _____________ |
| A. | zero |
| B. | cannot predict |
| C. | negative |
| D. | positive |
| Answer» D. positive | |
| 8. |
Consider the stencil. Give the advection flux at face e \((\dot{m_e}\phi_E)\) using the upwind scheme.(Note: \(\dot{m}\) and Φ are the mass flow rate and the flow variable respectively). |
| A. | \(\dot{m_e}\phi_E=max(\dot{m_e},0)\phi_C-max(-\dot{m_e},0)\phi_E\) |
| B. | \(\dot{m_e}\phi_E=min(\dot{m_e},0)\phi_C-max(-\dot{m_e},0)\phi_E\) |
| C. | \(\dot{m_e}\phi_E=max(\dot{m_e},0)\phi_C-min(-\dot{m_e},0)\phi_E\) |
| D. | \(\dot{m_e}\phi_E=min(\dot{m_e},0)\phi_C-min(-\dot{m_e},0)\phi_E\) |
| Answer» B. \(\dot{m_e}\phi_E=min(\dot{m_e},0)\phi_C-max(-\dot{m_e},0)\phi_E\) | |
| 9. |
The upwind scheme is dependent on the _____________ |
| A. | Convection term |
| B. | Peclet number |
| C. | Flow direction |
| D. | Gradient |
| Answer» D. Gradient | |
| 10. |
The upwind scheme is suitable for _____________ |
| A. | convection term |
| B. | diffusion term |
| C. | both convection and diffusion terms |
| D. | either convection or diffusion term |
| Answer» B. diffusion term | |