Aircraft Design: A Systems Engineering Approach, M. Sadraey, Wiley, Chapter 9 Landing Gear Design. Figures

Transcription

1 Aircraft Design: A Systems Engineering Approach, M. Sadraey, Wiley, 2012 Chapter 9 Landing Gear Design Figures cg strut wheel Main gear Height (H) Wheel base (B) cg Height (H) Wheel track (T) Figure 9.1. Landing gear primary parameters 1

2 Identify and prioritize landing gear design requirements Select landing gear configuration Select fixed or retractable Determine landing gear height Determine the distance between main gear to the aircraft center of gravity Determine wheel base Determine wheel track Determine load on each gear Is this landing gear satisfying the design requirements? No Yes Design/determine landing gear mechanical subsystems/parameters such as tires selection, retraction system, strut diameter, Castoring-wheel, shock absorber Optimization Figure 9.2. Landing gear design flowchart 2

3 Bottom view Side view 1. Single main 2. Bicycle 3. Quadricycle Bottom view Side view 4. Tricycle 5. Tail-gear 6. Multi-bogey 7. Releasable rail 8. Skid Figure 9.3. Landing gear types 3

4 1. Glider PZL-Bielsko SZD-48 Jantar Standard 3 with bicycle landing gear (Courtesy of Miloslav Storoska) 4

5 2. Douglas C-47A Skytrain (Courtesy of Jenny Coffey) 5

6 3. Transport aircraft McDonnell Douglas MD-88 with tricycle landing gear (Courtesy of Anne Deus) 4. Bomber aircraft B-52 Stratofortress with quadricycle landing gear is using parachute during a landing operation (Courtesy of Antony Osborne) 6

7 5. Transport aircraft Boeing 747 with multi-bogey landing gear (Courtesy of Anne Deus) Figure 9.4. Five example aircraft with various landing gear configurations 7

8 Aircraft or launcher Figure 9.5. Missile attachment 3-10 deg Tip float Waterline Deadrise Deadrise angle Spray strip a. Front-view CG Chine centroid b. Side-view Figure 9.6. Sea-plane landing provision geometry Waterline 8

9 Figure 9.7. Amphibious aircraft Canadian Vickers PBV-1A Canso (Courtesy of Jenny Coffey) 9

10 Figure 9.8. A pilot during running to launch himself off the top of a hill aboard a hang glider (Courtesy of Christopher Huber) 10

11 1. Van's RV-7 (Courtesy of Jenny Coffey) 11

12 2. Ilyushin IL-18 (Courtesy of A J Best) 12

13 3. Vickers VC10 (Courtesy of A J Best) 13

14 4. McDonnell Douglas C-17A Globemaster (Courtesy of Anne Deus) Figure 9.9. Example aircraft for landing gear attachments 14

15 Figure Aircraft Jindivik releases landing gear after take-off (Courtesy of 15

16 1. Fuselage podded (front-view) 2. In the wing (top-view) 3. In the fuselage (side-view) Figure Landing gear storage bay 16

17 1. Dassault Mirage 2000 with retractable landing gear (Courtesy of Jenny Coffey) 17

18 2. Robin DR Dauphin with faired fixed landing gear (Courtesy of Jenny Coffey) 18

19 3. Hawker Siddeley Nimrod with retractable landing gear (Courtesy of Antony Osborne) 19

20 4. Gippsland GA-8 Airvan with unfaired fixed landing gear (Courtesy of Jenny Coffey) Figure Four aircraft with various landing gear 20

21 H LG H LG 1. LG is attached to the fuselage (solid spring) 2. Main gear is attached to the wing H LG H LG 3. LG is attached to the fuselage (with outriggers) 4.Main gear is attached to the nacelle H LG H LG 5. LG is attached to the fuselage (rubber bungee) 6. LG is attached into the fuselage (no strut) Figure Landing gear height in various aircraft configurations 21

22 1. Take-off rotation ground clearance of Airbus A330 (Courtesy of Anne Deus) 22

23 2. Take-off rotation ground clearance of McDonnell Douglas F-15C Eagle (Courtesy of Antony Osborne) 23

24 TO B A clearance 3. Geometry of Take-off rotation ground clearance Figure Take-off rotation and rear fuselage clearance C H f B C C TO A H C Fuselage O Runway Figure Examination of rear fuselage clearance during take-off rotation 5 m 1 m Figure Figure for Example

25 cg cg W A o ½ F m F n T ½ F m F n B n W B Figure Wheel load geometry F m B m x Ground z Bm min Bn max Bn min Bm max cg for cg aft H cg F n Nose wheel B F m Main wheel o Figure Wheel load geometry 25

26 H cg cg cg H cg ot ot Y ot Wheel track Y ot ot based on top-view ot based on front-view Figure Overturn angle cg V cg F C H cg W ot F C R T Y ot 1. Top-view Front-view Figure An aircraft in a ground turn and overturn contributing factors 26

27 F W F W CA Cross wind cg CA W H C Cross wind O T 1. Top-view Front-view Figure An aircraft in a ground turn and overturn contributing factors Y ot A S cg Centroid H C Figure Aircraft side area and its centroid 27

28 y F x y max W T l 1. Aircraft structure 2. Beam with two simple supports Figure The aircraft structure at front view may be modeled as a beam with two simple supports tb Vertical Vertical tf TO cg cg h cg fi 1. Aircraft with tricycle landing gear 2. Aircraft with tail-wheel landing gear Figure Tipback angle, tipforward angle and take-off rotation 28

29 x- Ref. line X mg L wf Xac h V R Xac wf Mo wf T ma D Z cg Z T F f Z D L h X cg W Main gear x z z-ref. line Figure Forces and moments during take-off rotation 0.24C 0.2C 12 m 2 m cg ac wf 2.4 m T ac h 3 m D C Figure Aircraft in Example

30 Wheel Tire D t Figure Tire geometry W t 1. Solid spring 2. Oleo shock strut Figure Landing gear with shock absorber 30

31 Rake angle Trail Figure Steering wheel geometry Fuselage Figure Landing gear retraction subsystem 31

32 D 1.2 m 11.6 m 21 m 27 m cg 4 m Figure Aircraft in Example

33 cg 1.9 m m 1.9 m 1.2 m 3.1 m Figure Prop clearance x mg cg for h cg Figure Main gear and forward cg 33

34 1.9 m B m Fuselage upsweep point C C TO A H C Fuselage Figure Examination of rear fuselage clearance during take-off rotation T/2 cg Fuselage 30 o Wing 3.1 m Figure Wheel track (front view) 34

35 cg D H cg E1 ot D1 Y ot Nose gear A E cg D Y ot C F Main gear 1. Aircraft top view 2. Top view (main gear and nose gear) Figure Calculation of the overturn angle for the aircraft in Example

36 1.916 m m cg for cg aft m m 1. Wheel base, landing gear height, and main gear to cg cg cg m 1.2 m 3.58 m 2. Wheel track, clearance, and wheel height Figure The aircraft in Example 9.8 with the designed landing gear (figure not scaled) 36

37 1.3 m 12 m Figure Figure for problem 5 12 m 2 m cg ac wf 2.4 m T ac h 3 m D Figure Aircraft in problem 17 37

38 cg 1.6 m D 15 m 24 m 35 m Figure Aircraft in problem 19 cg D 2.2 m 1.4 m 20 m 32 m 48 m Figure Aircraft in Problem 20 38