Engineering Questions with Answers - Multiple Choice Questions

# MCQs on Turbulent Flow – 1

1 - Question

Is turbulent flow is characterized by chaotic changes in pressure and flow velocity?
a) True
b) False
Explanation: Turbulent flow is a flow regime in fluid dynamics characterized by chaotic changes in pressure and flow velocity. It is in contrast to a laminar flow regime, which occurs when a fluid flows in parallel layers, with no disruption between those layers.

2 - Question

Is turbulence is observed in the surf?
a) False
b) True
Explanation: Turbulence is commonly observed in everyday phenomena such as surf, fast flowing rivers, billowing storm clouds from a chimney and most fluid flows occurring in nature and created in engineering applications are turbulent.

3 - Question

Is turbulence is caused by excessive kinetic energy?
a) True
b) False
Explanation: Turbulence is caused by excessive kinetic energy in parts of a fluid flow, which overcomes the damping effect of the fluid’s viscosity. For this reason, turbulence is easier to create in low viscosity fluids but more difficult in highly viscous fluids.

4 - Question

Is unsteady vortices appears at turbulent flow?
a) True
b) False
Explanation: In turbulent flow, unsteady vortices appears of many sizes which interact with each other, consequently drag due to friction effects increases. This would increase the energy needed to pump fluid through a pipe, for instance.

5 - Question

Is laminar flow is used to increase the drag and reduce the lift?
a) True
b) False
Explanation: The effect can also be exploited by devices such as aerodynamic spoilers on aircraft, which deliberately spoil the laminar flow to increase the drag and reduce the lift on the aircraft, which also used as a break to stop the aircraft.

6 - Question

Is Reynolds number is used to predict the turbulence?
a) True
b) False
Explanation: The turbulence can be predicted by a dimensionless constant called Reynolds number, which calculates the balance between kinetic energy and viscous damping in a fluid flow. However, turbulence has long resisted detailed physical analysis, and the interactions within turbulence create a very complex situation.

7 - Question

Example of turbulent flow?
a) Smoking rises from cigarette
b) Flow on a symmetric airfoil
c) Laminar flow
d) Turbulent flow on the airfoil
Explanation: Smoke rising from a cigarette is mostly turbulent flow. However, for the first few centimeters, the flow is laminar. The smoke plume becomes turbulent as its Reynolds number increases, due to its flow velocity and the characteristic length.

8 - Question

Is flow over a golf ball is stationary?
a) True
b) False
Explanation: Flow over a golf ball, considering the golf ball to be stationary, with air flowing over it. If the golf ball to be stationary, with air flowing over it. If the golf ball were smooth, the boundary layer flow over the front sphere would be laminar at the typical condition.

9 - Question

Is surface is perturb the boundary layer and promote turbulence?
a) True
b) False