Explore topic-wise MCQs in Computational Fluid Dynamics.

This section includes 8 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.

Which of these terms represent convection in the momentum equation?

A. \(div(u\vec{V})\)
B. \(div(\rho \vec{V})\)
C. \(\nabla .(u\vec{V})\)
D. \(div(\rho u\vec{V})\)
Answer» E.
2.

The momentum equation is \( \rho\frac{Du}{Dt}=-\frac{\partial p}{\partial x}+\frac{\partial \tau_{xx}}{\partial x}+\frac{\partial \tau_{yx}}{\partial y}+\frac{\partial \tau_{zx}}{\partial z}+\rho f_x\). Which of these statements about sign convention can be inferred from this equation?

A. Pressure force is taken as negative
B. Tensile force is taken as negative
C. Pressure force is taken as positive
D. Pressure force is unsigned
Answer» B. Tensile force is taken as negative
3.

I am using an infinitesimally small element of fluid moving along with the flow as my model. What is the acceleration of this model in x-direction?

A. \(a_x=\frac{D\vec{V}}{Dt}\)
B. \(a_x=\frac{\partial \vec{V}}{\partial t}\)
C. \(a_x=\frac{Du}{Dt}\)
D. \(a_x=\frac{\partial u}{\partial t}\)
Answer» D. \(a_x=\frac{\partial u}{\partial t}\)
4.

The source term in the momentum equation is ________

A. Pressure force
B. Body forces
C. Viscous force
D. Acceleration
Answer» C. Viscous force
5.

The physical property Φ of the general transport equation is replaced by ________ to get momentum equation.

A. Velocity vector
B. Mass
C. Force vector
D. Acceleration vector
Answer» B. Mass
6.

Consider the element shown in the diagram. In diagram,p → pressure\(p+\frac{\Delta p}{\Delta x}dx=p+\frac{\partial p}{\partial x}dx\) dx, day, dz → dimensions in x, y and z directions What is the net pressure force in x direction?

A. \(-\frac{\partial p}{\partial x}\)
B. \(\frac{\partial p}{\partial x}\)
C. \(\frac{\partial p}{\partial x}dx \,dy \,dz\)
D. \(-\frac{\partial p}{\partial x}dx \,dy \,dz\)
Answer» E.
7.

Consider an element shown below. S is the source term. If gravitational force is the only force acting on this element. Which of these following is correct?

A. Sx=mg, Sy=0, Sz=mg
B. Sx=0, Sy=0, Sz=mg
C. Sy=0, Sz=0, Sx=mg
D. Sz=0, Sx=0, Sy=mg
Answer» E.
8.

What is the physical principle behind momentum equation?

A. Newton’s second law of motion
B. Newton’s first law of motion
C. Zeroth law of thermodynamics
D. First law of thermodynamics
Answer» B. Newton’s first law of motion