Download - NASA

More documents

Recommendations

Info

64 Aircraft Table 7-2. Component contributions to drag. component drag contribution reference area fuselage fuselage fuselage wetted area fuselage vertical fuselage projected area fittings and fixtures fuselage wetted area rotor-body interference fuselage wetted area contingency (aircraft) — payload increment (flight state) — landing gear landing gear — rotor hub, hub vertical rotor disk area pylon, pylon vertical pylon wetted area spinner spinner wetted area wing wing, wing vertical wing planform area wing-body interference wing planform area tail tail, tail vertical tail planform area engine nacelle, nacelle vertical nacelle wetted area momentum drag — fuel tank auxiliary tank (flight state) — Table 7-3. Component contributions to nominal drag area. component drag contribution cruise helicopter vertical fuselage fuselage fittings and fixtures D D D D DV D rotor-body int D D D landing gear landing gear D D 0 retractable 0 D 0 rotor hub D Dcos 2 i + DV sin 2 i 0 pylon D Dcos 2 i + DV sin 2 i 0 spinner D D 0 wing wing D Dcos 2 i + DV sin 2 i Dsin 2 i + DV cos 2 i wing-body int D D D tail horizontal tail D D DV cos 2 φ tail vertical tail D D DV sin 2 φ engine nacelle D Dcos 2 i + DV sin 2 i 0 contingency D D DV
Aircraft 65 7–10 Performance Indices The following performance indices are calculated for the aircraft. The aircraft hover figure of merit is M = W W/2ρAref/P . The aircraft effective drag is De = P/V , hence the effective lift-to-drag ratio is L/De = WV/P. Isolated rotor performance indices are described in chapter 11. 7–11 Weights The design gross weight WD is a principal parameter defining the aircraft, usually determined by the sizing task for the design conditions and missions. The aircraft weight statement defines the empty weight, fixed useful load, and operating weight for the design configuration. The aircraft weight statement is the sum of the weight statements for all the aircraft components, the component weight determined by input or by parametric calculations with technology factors. The definition of the weight terms is as follows. gross weight WG = WE + WUL = WO + Wpay + Wfuel operating weight WO = WE + WFUL useful load WUL = WFUL + Wpay + Wfuel where WE is the weight empty; WFUL the fixed useful load; Wpay the payload weight; and Wfuel the usable fuel weight. The weight empty consists of structure, propulsion group, systems and equipment, vibration, and contingency weights. If the weight empty is input, then the contingency weight is adjusted so WE equals the required value. If the design gross weight is input, then the payload or fuel weight must be fallout. The structural design gross weight WSD and maximum takeoff weight WMTO can be input, or specified as an increment d plus a fraction f of a weight W : WSD = dSDGW + fSDGWW = WMTO = dWMTO + fWMTOW = dSDGW + fSDGWWD dSDGW + fSDGW(WD − Wfuel + ffuelWfuel−cap) dWMTO + fWMTOWD dWMTO + fWMTO(WD − Wfuel + Wfuel−cap) This convention allows the weights to be input directly (f =0) or scaled with WD. For WSD, W is the design gross weight WD, orWD adjusted for a specified fuel state (input fraction of fuel capacity). The structural design gross weight is used in the weight estimation. For WMTO, W is the design gross weight WD, orWD adjusted for maximum fuel capacity. Alternatively, WMTO can be calculated as the maximum gross weight possible at a designated sizing flight condition. The maximum takeoff weight is used in the cost model, in the scaled aircraft and hub drag, and in the weight estimation. The design ultimate load factor nzult at the structural design gross weight WSD is specified, in particular for use in the component weight estimates. The structural design gross weight WSD and design ultimate load factor nzult are used for the fuselage, rotor, and wing weight estimations. The maximum takeoff weight WMTO is used for the cost and drag (scaled aircraft and hub), and for the weights (system, fuselage, landing gear, and engine group). The gross weight WG is specified for each flight condition and mission, perhaps in terms of the design gross weight WD. For a each flight state, the fixed useful load may be different from the design configuration because of changes in auxiliary-fuel-tank weight or kit weights or increments in crew or
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: Aircraft 63 disk area); or the drag
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 151 and 152:
Page 153 and 154:
Page 155 and 156:
Page 157 and 158:
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 and 172:
AFDD Weight Models 159 where fP = f
Page 173 and 174:
AFDD Weight Models 161 The conversi
Page 175 and 176:
AFDD Weight Models 163 19-12 Foldin
Page 177 and 178:
AFDD Weight Models 165 error (%) er
Page 179 and 180:
Page 181 and 182:
Page 183 and 184:
Page 185 and 186:
Page 187 and 188:
show all

Download - NASA

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?