İki Kişilik Hafif Askeri Eğitim Uçaği Gövde Dizayni

Abstract

Bu çalışmada; iki kişilik askeri hafif eğitim uçağı dizaynı kapsamında; gövde dizaynı çalışması yapılmıştır. Çalışma Roskam metoduna göre yapılmaya çalışılmıştır. Gövde dizaynın en temel olarak pilotun işlevliği, hareket ve görüş kabiliyeti hesaplarına göre belirlenmiştir. Ardından daire daire uzaklaşılarak komple kokpit ve gövde dizaynı yapılmıştır. Burada takip edilen Roskam metodu şartlarına göre aynı tip uçakların tipik boyutları da göz önünde bulundurularak; sınıf 1 dizayn kapsamında çalışma yapılmıştır. Bunun yanında dizayn kademelerinde IDEAS, ANYSY, CFD programları ile analiz ve çizim yapılmıştır. Bu çizimler, hesap işleminin hemen akabinde konular içerisinde verilmeye çalışılmıştır. Bu tez çalışması tekbaşına değil, aynı dönemde tezlerini sunan Zeki KESKİN, Selami KORKMAZ ve Ercan GÜNDOGDU'nun çalışmaları ile bir bütün teşkil etmektedir.

The aim of this research is to design of light aircraft for two persons. However Roskam method were used for this fuselage design, other same type aircraft's dimensions and calculatings were used. Fuselage design is the very important for aircraft design. Because cockpit is in this section. Base target of the design of the aircraft is useful for pilots and student. For that reason, design must start from standard pilot analysis and than must go on step by step. A good approach for design of fuselage is to calculate of aerodynamics properties and than we can find the best dimensions of the fuselage. First of all we shall find fuselage parameters. This parameters include as follows: 1. Friction drag, 2. Profile drag, 3. Base drag, 4. Compressibility drag, 5. Induced drag, The fuselage structure therefore must be designed so that the following types of load can be taken without major structural failures and without major structural fatigue problems: 1. Empenange loads due to trim, maneuvering, turbulence and gust. 2. Pressure loads due to cabin pressurization. 3. Landing gear loads while landing and take off. 4. Loads induced by the propulsion installation when the latter is attached to the fuselage. In 'survivable' crashes the fuselage must provide sufficient protection to prevent injuries to its occupants. Also cabin materials used for sound-proofing, decorative panels, seats, trays, and carpets must not generate toxic fumes when exposed to fire. XI The first chapter is start to calculating of this coefficients and drags. Especially drag is directly depend on the fines of the fuselage. Fines of the fuselage is L/D. L is lift and D is drag. We select 4.5 for the fines to get best result and small drag coefficient. Also this fines compared with other same type aircraft's all over the word and were found this approach is the good. And tail cone angle is 2 deg. Fuselage base dimensions were found from statistical calculating from same type aircraft's. The fuselage dimensions as follows: Cockpit capacity 2 person Fuselage length 1 92 cm Cockpit maximum height 134 cm Cockpit maximum width 1 07cm Fuselage maximum diameter 140 cm Fuselage cone length 374 cm fuselage Building depth 5 cm Fuselage fines 4.97 cm Tail tapering rate 2.67 Tail taper angle 8.5 deg. Designer of fuselage shall be carefully to carry of these loads : 1. Maneuvering Loads 2. Gusts loads 3. Turbulent loads 4. Pressurization loads 5. Engine trusts loads 6. Other special loads Federal Aviation Regulations recommend to apply +6 and -3 load coefficient for military aircraft's. For that reason; we calculate above loads for these load factors. Fuselage main structure dimension were found from previously same type aircraft's. Structure will be semi monococ structure and base properties shown as follows: Skeleton depth : 1,5 inch Skeleton space : 24-30 inch Longeron space : 10-15 inch under the above conditions; this aircraft fuselage sections and three view were drawn. Base cover thickness were found as follows 0.016 inch 0,02 inch 0,025 inch 0,032 inch XII Also materials selection is aluminum 2024. We did not use composite materials, Because of these materials required for high technologies and has very difficult manufacturing methods. Second section is cockpit design. Cockpit is the most important region of the fuselage. Because aircraft build for pilots and passenger. Pilots must easily reach all of the aircraft controls and must see all of the controls and panels. Also pilots must be reach all control with minimum effort. In this studies also standard pilot was designed. Related section provide information for standard pilot, baselines data for weights and for dimensions of ' standings' ( male) crew members. Notice that the center of gravity of a 'standing' crew member is roughly at the hip joint. Particularly when developing new cockpit or flight deck arrangements it is essential (before going in to the mock-up stage) to validate the proposed arrangement. This is done by constructing a ' puppet'. In the related section pilot model was given for designing. The pupped must be made to the same scale as the drawings of the proposed cockpit. The puppet made with rotating joints, using the joint rotation points. Other model was drawn with CAD/CAM program that name is ideas. Three dimensional pilot drawn in the ideas. And obtain information for mechanism data and relationship with leg, body, arms etc.. Minimum cockpit visibility rules are in force for civil as well as for military airplanes. Visibility from cockpit is defined by intersecting as the angular area obtained by intersecting the airplane cockpit with radial vectors emanating from eyes of the pilot. Although pilots generally see through both eyes, it is customary to construct the visibility pattern by assuming that mid point of eyes. Cockpit controls and cockpit construct according to this visibility conditions. XY, YZ and XZ visibility conditions were study according Roskam methods and found good conditions for pilots. After that drawings were added for this visibility. Seating layouts, seats and restrains system later designed according to visibility. These type of airplanes it is necessary carry a parachute. Parachute were worn as a back-pack Also some drawing added for parachute and layout. Other important system is the restrain systems. For protection of passenger and crew members in the case of flight through turbulence as well as in the case of a crash, restrain systems are required for crew members. It is essential that some areas of the fuselage which require frequent for inspection, replacement of parts or repairs be easily accessible. Design engineers need to work with airplane mechanics to find out the conditions under which typical inspection, maintenance and servicing procedures are being carried out. XIII From a structural design viewpoint the fuselage of most airplanes can be viewed as that component to which the wing, the Empenange and in some instance the landing gear etc. are attached. The possibility of liquid spillage exists in some aircraft. Floors need to be equipped with a drainage system. To be effective, the surrounding floor areas where they could cause corrosion or malfunctioning of equipment. All doors, exits and windows are potential sources for leaks, noise, drag and excess weight. But crew member comfort and emergency evacuation requirements demand a exits and windows. In this airplanes the wing attaches to the fuselage via three fuselage frames. In such cases the window spacing and sizing is dictated by structural considerations. In the other hands, we must bear in mind that any door or exit represents a potential leak, a potential drag cause ( because of seal deterioration) and a significant increment in weight. For that reason canopy is two parts and made of phylexiglass. In many airplanes the cabin windows are arranged to polarize the incoming light. This is to prevent glare and still allow the passenger the crew members to look out the windows. To cut noise coming through the wall, to provide thermal protection and to present a pleasant looking interior a series provisions are made to cabin inside. Baggage section is designed for personal materials and armaments. There is 100 lb. limits for design considerations. But there is not any limitations for volume of the baggage. For that reason baggage dimensions were calculated as follows : With : 60 cm Length : 110 cm Deep : 40 cm Volume : 264000 cm3 In this volume, two parachute and 10 G3 gun can be put in it. Cover of floor of the baggage is the block material without holes. Because fuel tank is located of the bottom side of the baggage. İTÜE1 fuel capacity is 320 litter. 190 litter fuel is in the wing tanks and 130 litters fuel is in the fuselage tank. This tank located behind of the seat and bottom side of the baggage. Baggage will divide some chamfer for leaking. Fuel tank dimensions as follows: XIV Other section is different previously chapter. This chapter tell how we can design sheet metal. Forming and bend allowance is the important for fuselage design. Bend allowance is defined as the amount of metal to be added to the total layout. Bend allowance depend on materials type, thickness and bend radius. Most of the aircraft manufacturers is designed sheet metal parts as fuselage according to experimental result and formulation. One of the most known formula for bend allowance is as follows: BA=(7txD)/(360/N°) BA is bend allowance; Pi is as known 3.1416, D İs bend radius times two plus the thickness of metal, N is the number of degrees of bend. Also other empirical formulation for bend allowance is : BA= ( 0.01743 x R + 0.0078 x T ) x N ° Setback is the calculating of the amount of metal to be subtracted frame a leg in order to find the length of its unbent portion. Simply stated setback is determined by subtracting the radius and the thickness from the length of the finished leg. SB = K x ( R + T ) Values of K are given in related chapter. Also can be calculated from trigonometric functions.