1. Team 5 Vehicle Propulsion PDR 1
Presented By: Maria Mullins Charles Reyzer
James Roesch Nick White

2. Sizing Revisions Weight Constraint Plot Correct Implementation
Modifications
Equations
February 10, 2005
AAE 451 – Team 5

3. Battery Weight Fraction Governing Equations
Straight Flight
Turning Flight
Climb
Total Fraction
February 10, 2005
AAE 451 – Team 5

4. Weight Guessing Inputs (DR&O) Output Vstall = 20 ft/s
Vloiter = 28 ft/s
Wpay = 0.2 lbf (gyro)
ρE ~ J/lbf*
Flight Time: 15 min
Output
WTOT = 0.6 lbf *
February 10, 2005
AAE 451 – Team 5

5. Constraint Equations Understood Thus Far
Climb
Stall
Take-Off
February 10, 2005
AAE 451 – Team 5

6. Constraint Plot Wing Loading: Power Loading: W/S = .38 lbf/ft2
W/Bhp = 26.9 lbf/Bhp
February 10, 2005
AAE 451 – Team 5

7. Weight Constraints Current Weight Propulsion Constraint Proportions
0.8 ft Boom Separation Required
Propulsion Constraint
0.917 ft propeller needed (11 in)
Proportions
1 ft clearance  4.75 ft Span
WNEW = 2.75 lb
February 10, 2005
AAE 451 – Team 5

8. Problem Solving for Sizing
Re-map historical data
Widen Booms
February 10, 2005
AAE 451 – Team 5

9. Motor Selection - Brushed
Graupner Speed V Electric
Based on Aircraft Weight ~2.75 lbs
For Airplanes weighing up to lbs
Cost: $16.90
February 10, 2005
AAE 451 – Team 5

10. Graupner Speed 500 7.2V February 10, 2005 AAE 451 – Team 5
Propeller Shaft
0.125 in ( ft)
Diameter
1.375 in ( ft)
Length
2.25 in ( ft)
Weight
lbs
Watts
199 W ( hp)
Volts
12 V
Amps
16 amp
Thrust
1.56 lbs
February 10, 2005
AAE 451 – Team 5

11. Finding RPM’s From Graupner website: RPM/V=2360 Assumptions:
Battery Voltage: 3.75V
8850 RPM
Assumptions:
2 batteries in series at 5 volts
February 10, 2005
AAE 451 – Team 5

12. Gear Box Selection Graupner Speed Gear 500/600 Gear Ratio: 2.8:1
Weight: lbs
Cost: Unknown at this time
February 10, 2005
AAE 451 – Team 5

13. Speed Controller Selection
Tiny GWS 5 Amp Micro Speed Control
Weight: lbs
Size: x x ft.
With Brake
Cost: $21.90
February 10, 2005
AAE 451 – Team 5

14. Propeller Properties Propeller Physical Data
Diameter = 11 inches
Pitch = 6 inches
Airfoil Sections
Hub: Eppler E 857
Tip: Eppler E 852
Twist = 26.34°
Propeller Performance Data (gold.m)
11 inches from motor selection
Pitch as suggested from Prof. Leasure and from actual RC aircraft propellers on tower hobbies
Twist and airfoil sections explained later slides
February 10, 2005
AAE 451 – Team 5

15. Cp and Ct plot from gold.m
Cp and CT get larger towards the tip of the propeller
Tip produces more power and thrust than hub
February 10, 2005
AAE 451 – Team 5

16. Propeller Airfoil Sections
Hub
Eppler E 857
High Clmax favorable for hub sections
Clmax needs to be high at hub
Lower Re needs thicker airfoil for better L/D
February 10, 2005
AAE 451 – Team 5

17. Propeller Airfoil Sections
Tip
Eppler E 852
Thin
High Clmax at lower angles of attack
Thin at tip.
Higher L/D
Better performance at higher Re
February 10, 2005
AAE 451 – Team 5

18. Hub Angle Based on Velocity Triangles Hub Radius 3/4” *
α for airfoil Clmax = 7°
Relative Velocity at 62.61° with horizontal flight
Twist hub at 55.62° to achieve Clmax at loiter
β = 7°
αrel = 55.62°
Uhub = nR = ft/s
Vx = 30 ft/s
αtot = 62.61°
*Tower Hobbies Propeller estimation
February 10, 2005
AAE 451 – Team 5

19. Tip Angle Based on Velocity Triangles Tip Radius 5.5”
α for airfoil Clmax = 4°
Relative Velocity at 85.96° with horizontal flight
Twist hub at 81.96° to achieve Clmax at loiter
β = 4°
αrel = 81.96°
Uhub = nR = ft/s
Vx = 30 ft/s
αtot = 85.96°
February 10, 2005
AAE 451 – Team 5

20. Actual RC Propeller Comparison
Tip
Hub
Picture of 11x6 Pusher Prop
February 10, 2005
AAE 451 – Team 5

21. Questions?
February 10, 2005
AAE 451 – Team 5