Computational Fluid Dynamics Practice Test 7

1. The realizable k-ε model is best for predicting __________

mixing layers

smooth boundary layer flows

spreading of jets

wake formation

2. To construct a high-resolution scheme, the monotonic profile in the range 0\(\leq\widetilde{\phi_c}\leq\)1 should pass through __________ in the NVD.

points (1,0) and (1,1)

points (0,0) and (1,1)

points (0,1) and (1,1)

points (0,0) and (0,1)

3. At high Reynolds numbers, the first wall damping function becomes ___________

∞

-1

4. Cross-stresses are caused by ___________

Resolved flow

Convection term

SGS eddies

Interaction of SGS eddies and resolved flow

5. The first wall damping function in the Spalart-Allmaras model is a function of ___________

the product of the dynamic eddy viscosity parameter and the dynamic eddy viscosity

the product of the kinematic eddy viscosity parameter and the kinematic eddy viscosity

the ratio of the dynamic eddy viscosity parameter and the dynamic eddy viscosity

the ratio of the kinematic eddy viscosity parameter and the kinematic eddy viscosity

6. The averaging interval in RANS equation is based on ____________

the time interval of the problem

the grid size

the fluctuations

the eddy size

7. Which of these is not a high-resolution scheme?

SMART

MINMOD

SIMPLE

MUSCL

8. The dynamic eddy viscosity used in the RNG k-ε model is ____________

thrice that of the k-ε model

twice that of the k-ε model

the same as that of the k-ε model

half of the that of the k-ε model

9. The realizable k-ε model falls into which of these categories?

Non-linear three-equation turbulence models

Linear two-equation turbulence models

Non-linear two-equation turbulence models

10. Which of these values vanish near the wall boundary?

Velocity and Reynolds number

k-value and Reynolds number

Velocity and k-value

Velocity and turbulent viscosity