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. |
The mixing length for a 2-D turbulent boundary layer depends on ____________ |
| A. | the distance from the wall and the boundary layer thickness |
| B. | the distance from the wall and von Karman s constant and dimensionless distance |
| C. | von Karman s constant |
| D. | the boundary layer thickness |
| Answer» C. von Karman s constant | |
| 2. |
Consider a turbulent flow of viscosity t, diffusivity t and Prandtl/Schmidt number t. Let be a flow property which can be decomposed into = + . What is the turbulent scalar flux given by? |
| A. | = <sub>t</sub> ( frac{ partial Phi}{ partial x} ) |
| B. | = <sub>t</sub> ( frac{ partial Phi}{ partial x} ) |
| C. | = <sub>t</sub> ( frac{ partial Phi}{ partial x} ) |
| D. | = <sub>t</sub> ( frac{ partial Phi}{ partial x} ) |
| Answer» B. = <sub>t</sub> ( frac{ partial Phi}{ partial x} ) | |
| 3. |
Mixing length model cannot be used for _____________ |
| A. | turbulent jets |
| B. | turbulent mixing layers |
| C. | turbulent wakes |
| D. | turbulent flows with separation |
| Answer» E. | |
| 4. |
The mixing length model can be used to get the turbulent scalar fluxes also using _____________ |
| A. | turbulent Prandtl/Reynolds number |
| B. | turbulent Reynolds/ Schmidt number |
| C. | turbulent Prandtl/Schmidt number |
| D. | turbulent Reynolds/Nusselt number |
| Answer» D. turbulent Reynolds/Nusselt number | |
| 5. |
What is the mixing length for the outer layer of a 2-D turbulent boundary layer? |
| A. | 0.09 times the boundary layer thickness |
| B. | 0.08 times the boundary layer thickness |
| C. | 0.07 times the boundary layer thickness |
| D. | 0.06 times the boundary layer thickness |
| Answer» B. 0.08 times the boundary layer thickness | |
| 6. |
For a 2-D flow, what is the mixing length of the mixing layer turbulence model? |
| A. | 0.1 of layer width |
| B. | 0.09 of layer width |
| C. | 0.08 of layer width |
| D. | 0.07 of layer width |
| Answer» E. | |
| 7. |
The value of mixing length depends on ____________ |
| A. | small eddies |
| B. | large eddies |
| C. | turbulence |
| D. | time scales |
| Answer» D. time scales | |
| 8. |
If t is the turbulent kinematic viscosity, lm is the mixing length and U is the mean flow velocity in the x-direction, which of these gives the Prandtl mixing length model equation? |
| A. | ( _t =l_m^2 Big| frac{ U}{ x} Big| ) |
| B. | ( _t =l_m^2 Big| frac{ U}{ y} Big| ) |
| C. | ( _t =l_m Big| frac{ U}{ y} Big| ) |
| D. | ( _t =l_m^2 Big| frac{ U}{ x} Big| ) |
| Answer» C. ( _t =l_m Big| frac{ U}{ y} Big| ) | |
| 9. |
The mixing length model links _____________ with _____________ |
| A. | length scale with mean flow properties |
| B. | velocity scale with mean flow properties |
| C. | length scale with position coordinates |
| D. | velocity scale with position coordinates |
| Answer» C. length scale with position coordinates | |
| 10. |
The mixing length model defines the turbulence dynamic viscosity as a function of ____________ |
| A. | position |
| B. | mean flow properties |
| C. | fluctuating components |
| D. | velocities |
| Answer» B. mean flow properties | |