1. Kurdistan regional government _ Iraq
Ministry of high education and scientific
Koya university
Facult of engineering
Manufacture department
A report about
Lifting force
Prepared by:
Ahmad sarbast amin
Group:A
Date of experiment: 8/12/2021
Date of submitting:13/12/2021
2. Abstract
Expected aerodynamical phenomena are explained. Lift force is obtained with three
methods which are theoretical, empirical, and finite volume better known as
(computational fluid dynamics) methods by computer. Ansys FLUENT R18.0 packed
software and MS Excel 2019 were used during computing and calculations. All results
are compared and commented via experimenters.
3. Introduction
Lift is defined as the total of all fluid dynamic forces acting on a body perpendicular to the
direction of external flow surrounding it.
There are various hypotheses about how lift is created; some are more complex than others,
while others have been proven to be incorrect. The simplest straightforward reason is that the
wing deflects air downward, which causes the wing to rise as a result of the reaction. Although
these theories are essentially various expressions of the same fundamental physics principles,
more complicated explanations focus on the air pressure around the wing.
Purpose of the Experiment
The purpose of this experiment is to measure the lift force which applied to selected airfoils
with a uniform flow in the wind tunnel. It is also used as a reference in later aircraft-wing
analysis. Measured lift force in the wind tunnel and the package software and interpreting the
similarities between the two proving with theoretical results. Then observe the experimental
laboratory environment to better understand and prove the mechanism of lifting force.
MATHEMATICAL FORMULATION
Archimedes’ Principle
Just how large a force is buoyant force? To answer this question, think about what happens
when a submerged object is removed from a fluid, as in (Figure). If the object were not in the
fluid, the space the object occupied would be filled by fluid having a weight
This weight is supported by the surrounding fluid, so the buoyant force must equal
the weight of the fluid displaced by the object.
Archimedes’ Principle
The buoyant force on an object equals the weight of the fluid it displaces. In equation
form, Archimedes’ principle is
where
is the buoyant force and
is the weight of the fluid displaced by the object.
This principle is named after the Greek mathematician and inventor Archimedes (ca. 287–212
BCE), who stated this principle long before concepts of force were well established.
4. Figure 14.21 (a) An object submerged in a fluid experiences a buoyant force
If
is greater than the weight of the object, the object rises. If
is less than the weight of the object, the object sinks. (b) If the object is removed, it is replaced
by fluid having weight
Since this weight is supported by surrounding fluid, the buoyant force must equal the weight of
the fluid displaced.
Archimedes’ principle refers to the force of buoyancy that results when a body is submerged in
a fluid, whether partially or wholly. The force that provides the pressure of a fluid acts on a
body perpendicular to the surface of the body. In other words, the force due to the pressure at
the bottom is pointed up, while at the top, the force due to the pressure is pointed down; the
forces due to the pressures at the sides are pointing into the body.
Since the bottom of the body is at a greater depth than the top of the body, the pressure at the
lower part of the body is higher than the pressure at the upper part, as shown in (Figure).
Therefore a net upward force acts on the body. This upward force is the force of buoyancy, or
simply buoyancy.
5. Table of test
No Material of
the body
FG(N) FG water Volume of
displace
1 Aluminum 2.3 1.5 85
2 Brass 4.2 4.18 56
3 Polyoxy
methelen
1.25 0.40 94
6. Discussion :
1. The real figure of the offered thing is measured. Calculation is done by
taking the measured numbers and plugging them into a formula. The
primary stage is measurement, whereas the secondary stage involves
calculation.
2. For example, to determine the actual value of grains per kilogram, we
must first weigh the required grains (measured value) and then multiply
the measured value by the per kilogram rate (calculated value)
3. The value of water is made up of FG and FG water, and Vdis is calculated by
reading the FG in air and FG in water, as well as volume displacement, in a
practical process. To compute, however, wemust first identify the FA and then
use a theoretical procedure to find the FG water. ue)
7. Refrence
Anderson, J. D. Jr., “Fundamentals of Aerodynamics”, 5th ed., McGraw Hill, New York,
2011, pp. 19-22,233-234,320-360.
[2] Barlow, J. B., Rae, W. H., and Pope, A., “Low-Speed Wind Tunnel Testing”, 3rd
ed., John
Wiley & Sons, New York, New York, 1999, pp. 6-8, 102-109, 471-482.
[3] Anderson, J. D., “Fundamentals of Aerodynamics”, 4th
ed., McGraw Hill, New York,
2007, pp. 19-30, 210-213.
[4] Anderson, J. D., “Introduction to Flight”, 8th
ed., McGraw Hill, New York, New York,
2015, pp. 322-324
