Download - NASA

More documents

Recommendations

Info

160 AFDD Weight Models and then WFWnb = χFWnbfFWnbw WFWmb = χFWmb(1 − fFWnb) w For a helicopter, the stabilizer-control equation is used. Parameters are defined in table 19-14, including units as used in these equations. Table 19-14. Parameters for fixed-wing flight-control weight. parameter definition units Sht horizontal tail planform area ft 2 WMTO maximum takeoff weight lb fFWnb fixed wing non-boosted weight (fraction total fixed wing flight control weight) Rotary-wing flight controls consist of non-boosted flight controls, flight-control boost mechanisms, and boosted flight controls. The non-boosted flight-control weight (AFDD82 model) is: fraction method WRW nb = χRW nbfRW nb(1 − fRW hyd)wfc parametric method WRW nb = χRW nb2.1785fnbsvW 0.3999 MTO N 1.3855 rotor where fnbsv =1.8984 for ballistically survivable (UTTAS/AAH level); 1.0 otherwise. The parametric method assumes the rotor flight controls are boosted and computes the weight of the non-boosted portion up to the control actuators. Based on 20 aircraft, the average error of the non-boosted flight controls equation is 10.4% (fig. 19-21). The flight-control boost-mechanism weight and boosted flight-control weight (AFDD82 model) are: wfc =0.2873fmbsv(NrotorNblade) 0.6257 c 1.3286 (0.01Vtip) 2.1129 f 0.8942 RW red WRW mb = χRW mb(1 − fRW hyd)wfc WRW b = χRW b0.02324fbsv(NrotorNblade) 1.0042 N 0.1155 rotor c 2.2296 (0.01Vtip) 3.1877 where fmbsv =1.3029 and fbsv =1.1171 for ballistically survivable (UTTAS/AAH level) and 1.0 otherwise; and fRW red =1.0 to 3.0. Typically fRW nb =0.6 (range 0.3 to 1.8) and fRW hyd =0.4. Based on 21 aircraft, the average error of the boost-mechanisms equation is 6.5% (fig. 19-22). Based on 20 aircraft, the average error of the boosted flight-controls equation is 9.7% (fig. 19-23). Parameters are defined in table 19-15, including units as used in these equations. Table 19-15. Parameters for rotary-wing flight-control weight. parameter definition units WMTO maximum takeoff weight lb Nrotor number of main rotors Nblade number of blades per rotor c rotor mean blade chord ft Vtip rotor hover tip velocity ft/sec fRW nb rotary wing non-boosted weight (fraction boost mechanisms weight) fRW hyd rotary wing hydraulics weight (fraction hydraulics plus boost mechanisms weight) flight control hydraulic system redundancy factor fRW red
AFDD Weight Models 161 The conversion controls consist of non-boosted tilt controls and tilt-control boost mechanisms; they are used only for tilting-rotor configurations. The weights are: wCV mb = fCV mbWMTO wCV nb = fCV nbWCV mb WCV mb = χCV mbwCV mb WCV nb = χCV nbwCV nb Parameters are defined in table 19-16, including units as used in these equations. Table 19-16. Parameters for conversion-control weight. parameter definition units WMTO maximum takeoff weight lb fCV nb conversion non-boosted weight (fraction boost mechanisms weight) conversion boost mechanisms weight (fraction maximum takeoff weight) fCV mb 19–9 Hydraulic Group The hydraulic group consists of hydraulics for fixed-wing flight controls, rotary-wing flight controls, conversion (rotor tilt) flight controls, and equipment. The hydraulic weight for equipment, WEQhud, is fixed (input). The weights (AFDD82 model) are WFWhyd = χFWhydfFWhydWFWmb WRW hyd = χRW hydfRW hydwfc WCV hyd = χCFhydfCV hydWCV mb Typically fRW hyd =0.4. Parameters are defined in table 19-17, including units as used in these equations. Table 19-17. Parameters for hydraulic group weight. parameter definition units fFWhyd fRW hyd fCV hyd fixed wing hydraulics weight (fraction boost mechanisms weight) rotary wing hydraulics weight (fraction hydraulics plus boost mechanisms weight) conversion hydraulics weight (fraction boost mechanisms weight) 19–10 Anti-Icing Group The anti-icing group consists of the electrical system and the anti-ice system. The weights are obtained from the sum over all rotors, all wings, and all engines: WDIelect = χDIelect kelecAblade WDIsys = χDIsys krotorAblade + kwingℓwing + kair Weng Parameters are defined in table 19-18, including units as used in these equations.
Page 1 and 2:
NASA/TP-2009-215402 NDARC NASA Desi
Page 3 and 4:
NASA/TP-2009-215402 NDARC NASA Desi
Page 5 and 6:
TABLE OF CONTENTS CHAPTER 1 - INTRO
Page 7:
TABLE OF CONTENTS (cont.) CHAPTER 1
Page 10 and 11:
viii LIST OF FIGURES (cont.) Figure
Page 13 and 14:
Chapter 1 Introduction The NASA Des
Page 15 and 16:
Introduction 3 of rotorcraft config
Page 17 and 18:
Introduction 5 previous case DESIGN
Page 19 and 20:
Introduction 7 4) Scully, M.; and F
Page 21 and 22:
Chapter 2 Nomenclature The nomencla
Page 23 and 24:
Nomenclature 11 Fuel Tanks Power Na
Page 25 and 26:
Nomenclature 13 Motion aF AC aircra
Page 27 and 28:
Chapter 3 Tasks The NDARC code perf
Page 29 and 30:
Tasks 17 engine group is found (inc
Page 31 and 32:
Tasks 19 3-4 Maps 3-4.1 Engine Perf
Page 33 and 34:
Chapter 4 Operation 4-1 Flight Cond
Page 35 and 36:
Operation 23 e) Input payload weigh
Page 37 and 38:
Operation 25 Table 4-1. Mission seg
Page 39 and 40:
Operation 27 horizontal ground dist
Page 41 and 42:
Operation 29 climb for zero power m
Page 43 and 44:
Operation 31 a) Horizontal velocity
Page 45 and 46:
Operation 33 From the pressure p =
Page 47 and 48:
Chapter 5 Solution Procedures The N
Page 49 and 50:
Solution Procedures 37 Sizing Task
Page 51 and 52:
Solution Procedures 39 relaxation i
Page 53 and 54:
Solution Procedures 41 Table 5-4. T
Page 55 and 56:
Solution Procedures 43 successive s
Page 57 and 58:
Solution Procedures 45 initialize e
Page 59 and 60:
Chapter 6 Cost Costs are estimated
Page 61 and 62:
Cost 49 Table 6-1. DoD and CPI infl
Page 63 and 64:
Cost 51 predicted base price (1994$
Page 65 and 66:
Chapter 7 Aircraft The aircraft con
Page 67 and 68:
Aircraft 55 The tilt control variab
Page 69 and 70:
Aircraft 57 forward axes for descri
Page 71 and 72:
Aircraft 59 For steady-state flight
Page 73 and 74:
Aircraft 61 where Δz F = z F − z
Page 75 and 76:
Aircraft 63 disk area); or the drag
Page 77 and 78:
Aircraft 65 7-10 Performance Indice
Page 79 and 80:
Aircraft 67 WEIGHT EMPTY STRUCTURE
Page 81 and 82:
Chapter 8 Systems The systems compo
Page 83 and 84:
Chapter 9 Fuselage There is one fus
Page 85 and 86:
Fuselage 73 αe = αfus − αzl, w
Page 87 and 88:
Chapter 10 Landing Gear There is on
Page 89 and 90:
Chapter 11 Rotor The aircraft can h
Page 91 and 92:
Rotor 79 propulsion group. The driv
Page 93 and 94:
Rotor 81 plane command. The collect
Page 95 and 96:
Rotor 83 or just CSF = WCHF with no
Page 97 and 98:
Rotor 85 If μ is zero, the equatio
Page 99 and 100:
Rotor 87 The velocity ratio is fW =
Page 101 and 102:
Rotor 89 T/T ∞ 1.3 1.2 1.1 1.0 Ha
Page 103 and 104:
Rotor 91 TPP tilt / cyclic magnitud
Page 105 and 106:
Rotor 93 with an average over the r
Page 107 and 108:
Rotor 95 (all equal to 1 for μz =0
Page 109 and 110:
Rotor 97 κ 1.30 1.25 1.20 1.15 1.1
Page 111 and 112:
Rotor 99 (C T /σ) s c d mean 0.20
Page 113 and 114:
Rotor 101 11-5.1.3 Twin Rotors For
Page 115 and 116:
Rotor 103 The wake is a skewed cyli
Page 117 and 118:
Rotor 105 weight per lifting rotor;
Page 119 and 120:
Chapter 12 Force The force componen
Page 121 and 122: Chapter 13 Wing The aircraft can ha
Page 123 and 124: Wing 111 denotes outboard edge, sub
Page 125 and 126: Wing 113 13-3.1 Lift The wing lift
Page 127 and 128: Wing 115 The wing interference at t
Page 129 and 130: Chapter 14 Empennage The aircraft c
Page 131 and 132: Empennage 119 14-4 Weights The tail
Page 133 and 134: Chapter 15 Fuel Tank 15-1 Fuel Capa
Page 135 and 136: Fuel Tank 123 if Wfuel >Wfuel−max
Page 137 and 138: Chapter 16 Propulsion The propulsio
Page 139 and 140: Propulsion 127 If the sum of the fi
Page 141 and 142: Chapter 17 Engine Group The engine
Page 143 and 144: Engine Group 131 The engine group p
Page 145 and 146: Engine Group 133 specific fuel cons
Page 147 and 148: Chapter 18 Referred Parameter Turbo
Page 149 and 150: Referred Parameter Turboshaft Engin
Page 159 and 160: Chapter 19 AFDD Weight Models This
Page 161 and 162: AFDD Weight Models 149 The spar-cap
Page 163 and 164: AFDD Weight Models 151 19-1.2 Aircr
Page 165 and 166: AFDD Weight Models 153 where w = nz
Page 167 and 168: AFDD Weight Models 155 units as use
Page 169 and 170: AFDD Weight Models 157 Table 19-9.
Page 171: AFDD Weight Models 159 where fP = f
Page 175 and 176: AFDD Weight Models 163 19-12 Foldin
Page 177 and 178: AFDD Weight Models 165 error (%) er
show all

Download - NASA

Create successful ePaper yourself

Delete template?

Save as template?