Design Of RC Aircraft

Roopal RajSandeep Kr.

Mishra Shreya Srivastava 6th B

Introduction:

A RC aircraft has all the dynamic characteristics which are present in actual aircraft.

RC Aircrafts can be used to carry some mass of small value or also use by defense authority by applying a spy camera on it. RC aircraft are also used by research and development department in order to check the feasibility of any design.

Airfoil:

An airfoil is the 2D cross-section shape of the wing, which creates sufficient lift with minimal drag.

Types:

Flat bottom airfoil Semi-Symmetric airfoil Symmetrical airfoil

Terminology

Airfoil selection:

We opted Symmetrical airfoil because It is use for airplanes having low Mach no. and good stability.

The selected profile was “naca0012” .

Lift • The component of the total aerodynamic force of an airfoil that is perpendicular to

the relative wind.

Drag• The component of the total aero – dynamic force of an airfoil that is parallel to the relative wind.

FL = CL ρ A v²/2

FD = CD ρ A v²/2

Motion Characteristics

Control Surfaces :Ailerons: An aileron is a hinged  flight control surface usually attached to the trailing arm of each wing of a fixed-wing aircraft. Movement around this axis is called 'rolling' or 'banking'.

Rudder:

The rudder are hinged on rear surface, making as a vertical stabilizer.  and its area is half of the whole vertical stabilizer.

Elevators:

The elevators are hinged on rear surface, making as a whole a tail plane or horizontal stabilizer. 

Stability Concept: Stability may be defined as follows: - Positive stability: tends to return to original condition after a disturbance. - Negative stability: tends to increase the disturbance. - Neutral stability: remains at the new condition.

Dynamic instability may be prevented by an even distribution of weight inside the fuselage, avoiding too much weight concentration at the extremities or at the CG.

Neutral point:

Neutral Point (NP) is the Aerodynamic Centre of the whole aircraft.

Centre of pressure: Centre of pressure Cp is a point on the wing

where the net lift force assume to be act. The distance of the Cp from leading edge is at

distance of “c/4” unit where “c ” is the chord length.

Aerodynamic center(AC): It is a point on the wing where the net pitching

moment is always constant.

Stability configuration:

Wing Analysis on JAVA Applet:

Calculations:

Wing area = FL ×2 /CL ×ρ ×V² = 10 ×2/0.278 ×1.228 ×10²

= 0.188m² Wing dimensions by taking aspect ratio as 6 =

0.188/1.06 = 0.178m

Area of horizontal stabilizer = wing area/4 = 0.188/4

= 0.94m² Area of vertical stabilizer = Area of horizontal

stab./2 = 0.94/2

= 0.47m²

From given diagram: L = 0.50 × 0.94/(0.188+ 0.94) = 0.42m.

FD = 0.0764 × 0.188 ×10 ×1.228/2 = 0.861 N

CATIA Model :

Flow simulation:

John J. Bertin “Aerodynamics for Engineers” Fourth Edition U.S Air force Academy.

John D. Anderson “Introduction to flight Dynamics” Third edition.

WikipediaSoftwares used : - JAVA Applet - Flow design - CATIA V5

Reference: