DR2 Stability and Control Preliminary Design Review and Performance PDR October 24, 2000 Presented By: Christopher Peters …and that’s cool Team DR2 Chris Curtis Loren Garrison Jeff Rodrian Mark Blanton S+C, PERFORMANCE PDR

DR2 S+C, PERFORMANCE PDR Presentation Outline: Stability and Control –Empennage sizing –Control Surface Sizing –CG, AC and NP Locations –Trim Discussion –Static Margin –Dutch Roll Mode –Short Period Mode Performance –Take-off and Climb –Turn –Endurance Projected Plan

DR2 S+C, PERFORMANCE PDR Empennage Sizing: Class I Sizing Approach –Sizing with Tail Volume Coefficients Vvt,Vht – ROSKAM II, SEC8 –Vvt = 0.04 –Vht = 0.5 Determined from Historical Data for small GA Aircraft, Homebuilt and Production. VT area generally too big… Need Class II Sizing to justify Size Selection –HT and VT analyzed using Class II Sizing

DR2 S+C, PERFORMANCE PDR Empennage Sizing: Class II Sizing Approach –HT Size HT using Center of Gravity (CG), Static Margin (SM), Tail Volume Coefficient (V ht ) and HT-Moment Arm (l ht ) Information. –VT Size VT using CG, C nβ, Tail Volume Coefficient (V vt ), and VT-Moment Arm (l vt ) Information.

DR2 S+C, PERFORMANCE PDR Empennage Sizing HT: For Electric Model Design assume the ability to pick CG by internal arrangement of Avionics and Electronics, to fit Desired SM Pick SM to fit Mission Modification of X-Plot Method necessary Analyze HT for Trimmed flight and Geometry Limitations

DR2 S+C, PERFORMANCE PDR Empennage Sizing HT: SM, 18% is Design Goal Possible Travel to Account for: 10%-25% –Due to Component Shift and Mission Modifications Neutral Point Location (X np ) Determined thru Trim- Analysis CG Set

DR2 S+C, PERFORMANCE PDR Empennage Sizing HT: Neutral Point Derivation: Calculation of l ht by S ht Variation – Limited by Length of Fuselage:

DR2 S+C, PERFORMANCE PDR Empennage Sizing HT Solution: S ht = 2.25ft 2 AR ht = 4 b ht = 3.0 ft c ht = 0.75 ft V ht = 0.5 l ht = ft

DR2 S+C, PERFORMANCE PDR Empennage Sizing VT: V vt Variation for S vt Calculation determined by Weathercock Criterion for ‘Manned Aircraft’: Simultaneously Calculation of l vt by V vt Variation – –Iteration Process, C nβ update – Effects on Dutch Roll Mode Weathercock: C nβ >= rad -1

DR2 S+C, PERFORMANCE PDR Empennage Sizing VT Solution: S vt = 0.77ft 2 AR vt = 2.5 b vt = 1.39 ft c vt = 0.56 ft V vt = l vt = 3.38 ft S vtHIST = 1.69ft 2

DR2 S+C, PERFORMANCE PDR Control Surface Sizing : Control Surface Sizing thru Class I Method: –Estimation based on Empirical Data From ROSKAM II/8 and former 451 Reports: –Elevator: 40%c root – 45%c tip, Full Span –Rudder: 35% c root - 48% c tip, Full Span –Aileron: 25% c w – 60% Span –Deflection Limits: Rudder/Elevator: +/- 10º –Flat Plate Airfoil Approximation – Separation –No Dihedral, Rudder and Aileron Control

DR2 S+C, PERFORMANCE PDR Aerodynamic Center, CG, SM: Aerodynamic Center Wing –23% of C mean – For Biplanes (Raymer) Aerodynamic Center Aircraft –As shown Before, X np = 1.85ft (from FS 0, - Nose of A/C) CG –SM = 18%, CG = FS 1.68 –SM = 10%, CG = FS 1.75 –SM = 25%, CG = FS 1.61

DR2 S+C, PERFORMANCE PDR Aerodynamic Center, CG, SM: CG Calculation, Mass Inertias –Component Shift to meet SM = 18% –Determine Mass Inertias for given CG –I xx = 0.5 slugs-ft^2 –I yy = 0.54 slugs-ft^2 –I zz = 0.96 slugs-ft^2

DR2 S+C, PERFORMANCE PDR Trim: Force and Moment Balance

DR2 Moment Coefficient: S+C, PERFORMANCE PDR i wu = 0 deg i wl = -2 deg i ht = 0 deg

DR2 Trim Conditions S+C, PERFORMANCE PDR

DR2 S+C, PERFORMANCE PDR Trim Conditions

DR2 S+C, PERFORMANCE PDR Dutch Roll Mode: ζ DR = ω DR =2.102

DR2 S+C, PERFORMANCE PDR Short Period Mode Approximation (after DR K. Hout): ζ SP = 0.57 ω SP =5.62

DR2 S+C, PERFORMANCE PDR Performance Endurance –After propulsion PDR II Endurance Requirement met and exceeded at V loiter =25 ft/s Takeoff Distance –Less than 35 ft –At Climbangle > 6deg. –Easily meeting abort mission and climb constraints

DR2 S+C, PERFORMANCE PDR Performance Projected Work –Detailed Analysis of Performance Parameters Take-off Turning –Dynamic Simulation of Aircraft –Mission Analysis with finalized Parameters