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

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

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

Weight Guessing Inputs (DR&O) Output Vstall = 20 ft/s Vloiter = 28 ft/s Wpay = 0.2 lbf (gyro) ρE ~ 230000 J/lbf* Flight Time: 15 min Output WTOT = 0.6 lbf *www.towerhobbies.com February 10, 2005 AAE 451 – Team 5

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

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

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

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

Motor Selection - Brushed Graupner Speed 500 7.2V Electric Based on Aircraft Weight ~2.75 lbs For Airplanes weighing up to 3.125 lbs Cost: $16.90 February 10, 2005 AAE 451 – Team 5

Graupner Speed 500 7.2V February 10, 2005 AAE 451 – Team 5 Propeller Shaft 0.125 in (0.0104 ft) Diameter 1.375 in (0.1146 ft) Length 2.25 in (0.1875 ft) Weight 0.0357 lbs Watts 199 W (0.2669 hp) Volts 12 V Amps 16 amp Thrust 1.56 lbs February 10, 2005 AAE 451 – Team 5

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

Gear Box Selection Graupner Speed Gear 500/600 Gear Ratio: 2.8:1 Weight: 0.0992 lbs Cost: Unknown at this time February 10, 2005 AAE 451 – Team 5

Speed Controller Selection Tiny GWS 5 Amp Micro Speed Control Weight: 0.011 lbs Size: 0.0705 x 0.0344 x 0.0180 ft. With Brake Cost: $21.90 February 10, 2005 AAE 451 – Team 5

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

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

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

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

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 = 57.92 ft/s Vx = 30 ft/s αtot = 62.61° *Tower Hobbies Propeller estimation February 10, 2005 AAE 451 – Team 5

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 = 424.77 ft/s Vx = 30 ft/s αtot = 85.96° February 10, 2005 AAE 451 – Team 5

Actual RC Propeller Comparison Tip Hub Picture of 11x6 Pusher Prop http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LX1502&P=0 February 10, 2005 AAE 451 – Team 5

Questions? February 10, 2005 AAE 451 – Team 5