Explore topic-wise MCQs in Computational Fluid Dynamics.

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.

LES Reynolds stresses are caused by ____________

A. Source term
B. Resolved flow
C. SGS eddies
D. Diffusion term
Answer» D. Diffusion term
Discussion
2.

Cross-stresses are caused by ___________

A. Convection term
B. Resolved flow
C. SGS eddies
D. Interaction of SGS eddies and resolved flow
Answer» E.
Discussion
3.

Leonard stresses are caused by ____________

A. The SGS eddies
B. The effects at the resolved scale
C. The effects of the unresolved variables
D. The combined effect of the SGS eddies and the resolved scale
Answer» C. The effects of the unresolved variables
Discussion
4.

If a flow variable ϕ can be resolved by spatial LES filtering as Φ and Φ’. Expand the term \(\rho\overline{u_iu_j}\).

A. \(\rho\overline{\overline{u_i}\overline{u_j}} + \rho\overline{\overline{u_i}u_j^{‘}} + \rho\overline{u_i^{‘}\overline{u_j}}\)
B. \(\rho\overline{\overline{u_i}\overline{u_j}} + \rho\overline{u_i^{‘}u_j^{‘}}\)
C. \(\rho\overline{\overline{u_i}u_j^{‘}} + \rho\overline{u_i^{‘}\overline{u_j}}\)
D. \(\rho\overline{\overline{u_i}\overline{u_j}} + \rho\overline{\overline{u_i}u_j^{‘}} + \rho\overline{u_i^{‘}\overline{u_j}}+\rho\overline{u_i^{‘}u_j^{‘}} \)
Answer» E.
Discussion
5.

The SGS stresses are obtained from ___________

A. Reynolds stress term
B. Convection term
C. Source term
D. Diffusion term
Answer» B. Convection term
Discussion
6.

Which of these terms corresponds to the cross stresses?

A. \(\rho\overline{u_i^{‘}\overline{u_j}}\)
B. \(\rho\overline{\overline{u_i}u_j^{‘}}\)
C. \(\rho\overline{\overline{u_i}u_j^{‘}} + \rho\overline{u_i^{‘}\overline{u_j}}\)
D. \(\rho\overline{\overline{u_i}u_j^{‘}}\, – \rho\overline{u_i^{‘}\overline{u_j}}\)
Answer» D. \(\rho\overline{\overline{u_i}u_j^{‘}}\, – \rho\overline{u_i^{‘}\overline{u_j}}\)
Discussion
7.

The stress term \(\rho\overline{u_i^{‘}u_j^{‘}}\)is called as ____________

A. Filter Reynolds stress
B. LES Reynolds stress
C. Reynolds stress
D. Sub-Reynolds stress
Answer» C. Reynolds stress
Discussion
8.

Identify Leonard stresses from the following.

A. \(\rho\overline{\overline{u_i}\overline{u_j}}\, – \rho\overline{u_i}\overline{u_j}\)
B. \(\rho\overline{\overline{u_i}\overline{u_j}}\)
C. \(\rho\overline{u_i}\overline{u_j}\)
D. \(\rho\overline{\overline{u_i}\overline{u_j}}\, – \rho\overline{u_i}\overline{u_j}\)
Answer» B. \(\rho\overline{\overline{u_i}\overline{u_j}}\)
Discussion
9.

How many extra stress terms occur due to the LES filtering operation?

A. No extra terms
B. Four terms
C. Three terms
D. Two terms
Answer» D. Two terms
Discussion
10.

When is the LES filter commutative?

A. When the filter function is unity
B. When the filter function is quadratic
C. When the filter function is isotropic
D. When the filter function is uniform
Answer» E.
Discussion