1. Propeller Based Propulsion
P M V Subbarao
Professor
Mechanical Engineering Department
Both Lift and Thrust using Pure Wright Brother’s Idea!!!

2. Working Principle of Propeller Aircraft

3. Anatomy of Propeller

4. Velocity & Force Vectors across A Propeller

5. Creation of Useful Velocity Triangle
The propeller blade will be set at a given geometric pitch angle ()
The local velocity vector will create a flow angle of attack () on the section A-A.
V0 -- axial flow at propeller disk,
V2 -- Angular flow velocity vector
V1 -- section local flow velocity vector, summation of vectors V0 and V2

6. Forces Generated by An Infinitesimal Blade ElementV0
V2 = r V1
The elemental thrust (dT) and torque (dQ) of this blade element can thus be written as

7. Static Performance of an Airfoil

8. Force System on an Airfoil
The surface pressure is non-dimensionalised using the dynamic pressure, giving the pressure coefficient, :

9. Static Performance of An Airfoil
Static stall

10. Local Forces on A Blade Element : Propeller
For a constant V1 V0
Steady stall V1

11. Lift and drag coefficients for the NACA 0012 symmetric airfoil : Preferred Reynolds Number Range

12. Lift and drag coefficients for the NACA 63(2)-215 airfoil : Preferred Reynolds Number Range

13. Dynamic Performance of an Airfoil
Consider an airfoil of chord length of c, pitching about the mid-chord at a constant pitch rate (rad/s).
Define, the reduced frequency as
NACA 0015
Comparison with the steady-state case indicates that the airfoil can generate increasing lift forces beyond the critical stall angle of attack with increasing reduced frequency

14. Enhanced Lift due to Dynamic State of Airfoli

15. Forces Generated by An Infinitesimal Blade ElementV0
V2 = r V1
The elemental thrust (dT) and torque (dQ) of this blade element can thus be written as
For each blade element:

16. Infinitesimal Propeller Element

17. Forces Generated by An Infinitesimal Propeller Element
If the number of propeller blades is (B) then,
The incremental thrust generated by the rotor is:
The driving torque on the rotor shaft is:
The incremental Power input to the shaft is:

18. Total Power Input to the Propeller
The absorbed power is often non-dimensionalized with respect to as a power coefficient CP:

19. Capacity of A Successful Propeller

20. Engines to drive propeller

21. Propellers for Helicopter
Each rotor blade (1) is connected to the hub (2) and rotating mast by a feathering hinge (3), which allows it to swivel.

22. A pitch link (a short rod) attached to each blade (4) can tilt it to a steeper or shallower angle according to the position of the rotating upper swash plate (5).
Swash plate spins on bearings around the static lower swash plate (6).
That's how a chopper hovers and steers and it's described in more detail later in this article.

23. The two swash plates are moved up and down or tilted to the side by the pilot's cyclic and collective cockpit contro. The rotor is powered by a driveshaft (7) connected to a transmission and gearbox (8).
The same transmission powers a second, longer driveshaft (9) connected to a gearbox that spins the tail rotor (10).
The power from both rotors comes from one or two turboshaft jet engines (11).

24. Vertical Ascent
Thrust + Lift
Weight + Drag

25. Forward Flight
Resultant
Lift
Thrust

26. Hover
Thrust + Lift
Weight+ Drag

27. Vertical Descent
Thrust + Lift
Weight + Drag

28. Rearward Flight
Resultant
Lift
Thrust

29. Sideward Flight
Resultant
Resultant
Lift
Lift
Side Thrust
Side Thrust

30. Bell 429 Exceptional Speed and Class Leading Performance
Max Cruise
278 km/h
Range at VLRC*
761 km
POWERPLANT (2) Pratt & Whitney Canada PW207D1
Transmission Rating, MCP
820 kW
Output Shaft Speed (RPM)
Diameter** (Inches)
Length** (Inches)
PW207 Series
6,000 to 6,240 22
36 to 40

31. The Structure of PW207 Series
Single stage, centrifugal compressor :Compact and efficient, Radial inlet with screen for FOD protection, No overboard compressor bleed.
Reverse flow combustor: Low smoke, high stability, easy starting, durable.
Single stage high pressure turbine : Advanced technology and low parts count for long life and low maintenance cost
Single-stage shrouded power turbine : High efficiency and low vibration
Combined Reduction and Accessory gearbox
Two-stage, compact drive train with precise electronic torquemeter and integrated oil tank.