Experiment on Fluids:
Finding the Velocity of a Fluid in a Confined Container
SUBJECT: Aeronautics
TOPIC: Fluid Velocity
DESCRIPTION: A set of mathematics problems dealing with fluid velocity.
CONTRIBUTED BY: Carol Hodanbosi
EDITED BY: Jonathan G. Fairman  August 1996
Purpose:
To calculate the velocity of a confined fluid, given the
crosssection area and velocity of another region.
Concept:
The drawing below is a crosssection of a circular cone attached
to a circular cylinder.
When a fluid (liquid or gas) is in a confined space, with no
change in pressure or temperature, one can use the equation of
continuity to find the velocity of the fluid if one knows the
crosssection area and velocity in one of the regions. The formula
for this is A1*V1 = A2*V2, where A is the crosssection area
of one location and V is the velocity for that location.
Analysis:
Given three different locations in a confined container, A, B, and
C, all having different radii, can you find the other two velocities
of the fluid, if the velocity at A is given?
 If the crosssection at A has a radius of 6 meters, can you
find the area of the slice through the cone
(Area = pi * r ^{ 2})?
(answer)
 If the velocity of the fluid at location A is 10.0 m/s,
and the radius at location B is 4.2 meters, can you find
the velocity at location B?
(answer)
 If the velocity at location C is 8.6 m/s, can
you find the radius at location C?
(answer)
Extension:
 If the radius of a fourth location, D, is onehalf the
radius of A , how would the velocity at location D
compare to the velocity of the fluid at A? If D had
onethird the radius of A, compare the velocity of the
fluid at D to A. Explain your reasoning showing
calculations.
(answer)
Related Pages:
Aeronautics Activities
Aerospace Activities Page
Aerodynamics Index
Continuity Equation
Air Flow Rate
