# – Vortex Flow

This set of Aerodynamics Multiple Choice Questions & Answers (MCQs) focuses on “Vortex Flow”.

1. The strength of the vortex flow can be given by ______________
a) Γ=2*pi*C
b) Γ=2*pi
c) Γ=-2*pi*C
d) Γ=0

Explanation: The circulation for vortex flow can be given by –
Γ=2*pi*C where, C – constant and Γ is the strength of the vortex flow.
When Γ is positive, it means that vortex of positive strength rotates in the clockwise direction and vice versa.

2. The combination of uniform flow and source flow gives ___________
a) flow past a cylinder
b) flow past a half body
c) flow past a full body
d) flow past a wedge

Explanation: When a uniform of velocity U combines with a source flow of strength q, the resultant flow is a flow over a half body. 3. The circles with their centre on the X axis _____________
a) eccentric circles
b) concentric circles
c) potential lines
d) equal circles

Explanation: Potential lines are eccentric non-intersecting circles with their centres on x-axis. The potential lines for source pair will be eccentric non-intersecting circles. 4. Centre of pressure can be calculated using __________
a) Principle of moments
b) Principle of energy
c) Mass conservation
d) Rayleigh’s principle

Explanation: The principle of moments asserts that the moment of the resultant force about an axis equals the sum of the moments of the components around the same axis.

5. A body floats on the surface when ____________
a) metacenter is above gravity
b) metacenter is below gravity
c) metacenter is equal to gravity
d) gravity is above metacenter

Explanation: The metacenter of a floating item should always be above gravity. When a body is slanted by a modest degree, the metacentre is the point around which it begins to oscillate. The weight of an object is equal to the amount of fluid displaced in the case of a floating body.

6. The free vortex flow forms _________
a) straight lines
b) concentric circles
c) parabola
d) hyperbola

Explanation: The free vortex flow is a fluid circulatory flow with stream lines that are concentric circles. Ur and U are the velocity components of a free vortex flow, with Ur=0 and U=circulation/ 2*pi*r.

7. The following figure is an example of ____________ a) source flow
b) sink flow
c) doublet
d) free vortex flow

Explanation: The concentric rings and streamlines are seen in the diagram above. The streamlines are concentric because the stream function is a function of radius and has a constant value.

8. Except at the origin where r=0, the vortex flow is ___________
a) rotational
b) laminar
c) irrotational
d) turbulent

Explanation: Except at r=0, when the vorticity is unlimited, vortex flow is irrotational everywhere. As a result, the flow field’s origin, r=0, is a unique point. The singularity point is represented by the genesis point.

A vortex (plural vortices/vortexes) is an area in a fluid where the flow spins around an axis line that might be straight or curved in fluid dynamics. Vortices are defined by their velocity distribution, vorticity (the curl of the flow velocity), and the idea of circulation. Except at r=0, when the vorticity is unlimited, vortex flow is irrotational everywhere. As a result, the flow field’s origin, r=0, is a unique point. The singularity point is represented by the genesis point.