Roopal Raj Roopal Raj Sandeep Kr. Mishra Sandeep Kr. Mishra Shreya Srivastava Shreya Srivastava 6 6thth B B
Introduction
Introduction
::
A R
A R
C
C
aircr
aircr
aft
aft
has
has
all the
all the
dynamic
dynamic
chara
chara
cteristics
cteristics
which
which
are present in actual aircraft.
are present in actual aircraft.
RC Aircrafts can be used to carry
RC Aircrafts can be used to carry
some mass of
some mass of
small value or also
small value or also
use by defense authorit
use by defense authorit
y by applying
y by applying
a spy camera on it
a spy camera on it
..
RC aircr
RC aircr
aft are also used
aft are also used
by research
by research
and development departmen
and development departmen
t in order to
t in order to
check th
check th
e
e
feasibility of any design.
Airfoil:
Airfoil:
An An airfoil is airfoil is the 2the 2D crD cross-section oss-section shape shape of the of the wing,wing, which
which creates creates sufficient lift sufficient lift with miwith minimal nimal dragdrag..
T Typesypes::
Flat bottom airfoilFlat bottom airfoil
Semi-Symmetric airfoilSemi-Symmetric airfoil
Terminology
Airfoil selection:
Airfoil selection:
W We e opted Sopted Symmetricalymmetrical
airfoil because It is use
airfoil because It is use
for airplanes having
for airplanes having
low
low Mach Mach no. no. andand
good stability.
good stability.
The selected profileThe selected profile
was
Lift Lift
•
• The component of the total aerodynamic force of an The component of the total aerodynamic force of an airfoil that is perpendicular toairfoil that is perpendicular to
the relative wind.
the relative wind.
Drag Drag
•
• The component of the total aeroThe component of the total aero – –
dynamic force of an airfoil that is
dynamic force of an airfoil that is
parallel to the relative wind.
parallel to the relative wind.
F
FLL = C = CLL ρρ A v²/2 A v²/2
F
Motion Characteristics
Control Surfaces :
Control Surfaces :
Ailerons:
Ailerons:
An An aileron aileron is is a hinga hinged ed fflight light contrcontrolol
surface usually attached to the trailing
surface usually attached to the trailing
arm of each wing of a
arm of each wing of a fixed-wingfixed-wing
aircraft.
aircraft.
MovMovement around thement around this axis is calledis axis is called
'rolling' or 'banking'.
Rudder:
Rudder:
The rudder are hinged on rearThe rudder are hinged on rear
surface, making as a vertical stabilizer
surface, making as a vertical stabilizer ..
and its area is half of the whole vertical
and its area is half of the whole vertical
stabilizer.
stabilizer.
Elevators:
Elevators:
The elevators are hinged on rearThe elevators are hinged on rear
surface, making as a whole a tail
surface, making as a whole a tail
plane or horizontal stabilizer
Stability Concept:
Stability Concept:
Stability may be defined as follows:Stability may be defined as follows:
- Positive stability: tend
- Positive stability: tends to rs to return to original conditioneturn to original condition
after a disturbance.
after a disturbance.
- Negative stability: tends to increase the disturbance.
- Negative stability: tends to increase the disturbance.
- Neutral stability: remains at the new condition
- Neutral stability: remains at the new condition..
Dynamic instDynamic instabilitability may be prevy may be prevented ented by an evby an evenen
distribut
distribution of weight inside the fuselage, avoiding tooion of weight inside the fuselage, avoiding too
much weight c
Neutral point:
Neutral point:
Neutral Point (NP) Neutral Point (NP) is the Aerodynamic Centre is the Aerodynamic Centre of tof the wholehe whole
aircraft.
aircraft.
Centre
Centre
of p
of p
ressure:
ressure:
Centre of pressCentre of pressure Cp is a point on the wing where the neture Cp is a point on the wing where the net
lift force assume to be act.
lift force assume to be act.
The distance of the Cp from leadinThe distance of the Cp from leading edge is at g edge is at distance ofdistance of
“c/4” unit where “
“c/4” unit where “c ” is tc ” is the chord lengthe chord length.h.
Aer
Aer
odynami
odynami
c
c
cent
cent
er(A
er(A
C):
C):
It is a point on the It is a point on the wing where the net piwing where the net pitching moment tching moment isis
always c
Stability configuration:
Wing Analysis on JAVA Applet:
Calculations:
Calculations:
Wing a
Wing a
rea
rea
=
=
F
F
LL×2×2/
/
CCLL×
×
ρρ×V²
×V²
=
=
10 ×2/0.278 ×1.228 ×10
10 ×2/0.278 ×1.228 ×10
²²=
= 0.188m²0.188m²
Wing Wing dimensions dimensions by by taking taking aspect aspect ratio ratio as 6 =as 6 = 0.188/1.060.188/1.06
= 0.178m
= 0.178m
Area of Area of horizontal stabihorizontal stabilizer = wing lizer = wing area/4area/4
= 0.188/4
= 0.188/4
= 0.94m
= 0.94m
²
²
Area Area of vof vertical stabilizer ertical stabilizer = Ar= Area ea of horizontal stabof horizontal stab./2./2
= 0.94/2
=
= 0.47m0.47m²²
From given diagram:
From given diagram:
L = 0.50 L = 0.50 ×× 0.94 0.94/(0.188+ 0.94)
/(0.188+ 0.94)
= 0.42m.
= 0.42m.
F
F
DD = 0.0764= 0.0764 ×× 0.188 0.188 ××1010 ××1.228/21.228/2= 0.861 N
= 0.861 N
CA
Flow simulation:
John
John
J.
J.
Bertin
Bertin
“
“
Aerodynamics
Aerodynamics
for Engine
for Engine
ers”
ers”
Fourth Edition U.S Air force Academy.
Fourth Edition U.S Air force Academy.
John
John
D
D
. Anderson
. Anderson
“Introduction
“Introduction
to
to
f
f
light
light
Dynamics” Third edition.
Dynamics” Third edition.
Wikipedia
Wikipedia
