Bir temel eğitim uçağı için optimum dümen tork tüpü tasarımı
Optimum rudder torque tube design for a basic trainer aircraft
- Tez No: 972090
- Danışmanlar: PROF. DR. ZAHİT MECİTOĞLU
- Tez Türü: Yüksek Lisans
- Konular: Havacılık ve Uzay Mühendisliği, Uçak Mühendisliği, Aeronautical Engineering, Aeronautical Engineering
- Anahtar Kelimeler: Belirtilmemiş.
- Yıl: 2025
- Dil: Türkçe
- Üniversite: İstanbul Teknik Üniversitesi
- Enstitü: Lisansüstü Eğitim Enstitüsü
- Ana Bilim Dalı: Uçak ve Uzay Mühendisliği Ana Bilim Dalı
- Bilim Dalı: Uçak ve Uzay Mühendisliği Bilim Dalı
- Sayfa Sayısı: Belirtilmemiş.
Özet
Havacılıkta geçmişten günümüze kadar birçok hava aracı tasarlanmıştır. Bu tasarımlar, uçağın görevine, müşteri gereksinimlerine, üreticinin üretim kapasitesine ve belirlenen bütçeye bağlı olarak değişiklik göstermektedir. Mühendislerin temel görevi, tüm bu koşulları göz önünde bulundurarak en uygun tasarımı ortaya koymaktır. Pilot eğitiminde kritik bir rol üstlenen temel eğitim uçakları, tasarım açısından çeşitlilik barındırmaktadır. Bu çeşitliliği belirleyen unsurlardan biri de pilotların oturma düzenidir. Söz konusu düzen, gövde, kuyruk ve kanat boyutlarını doğrudan etkilemektedir. Uçak tasarımı dışarıdan bakıldığında kanat, gövde ve kuyruk gibi temel bileşenlerden oluşuyor gibi görünse de iç sistemler, uçağın görevini güvenli bir şekilde yerine getirebilmesi için hayati öneme sahiptir. Kontrol sistemleri, ana ve ikincil sistemler olarak ikiye ayrılır. Ana kontrol sistemleri, uçağın emniyetli şekilde kontrol edilmesini sağlarken; ikincil sistemler, pilotun iş yükünü azaltmayı hedefler. Ana kontrol sistemlerinin en önemli bileşenlerinden biri olan dümen kontrol sistemi, pilotun dümen pedallarına uyguladığı kuvvetle uçağın sapma hareketini yönetmektir. Bu sistemin kritik bir parçası ise dümen ile mekanik bağlantıyı sağlayan tork tüpüdür. Bu çalışmanın amacı, temel bir eğitim uçağı için optimum tork tüp tasarımını geliştirmektir. Çalışma kapsamında öncelikle literatür araştırması yapılmış ve temel eğitim uçakları arasından T-6C Texan II modeli referans alınmıştır. Uçuş kontrol sisteminin tanımlanmasının ardından, mekanik ve elektronik sistemler karşılaştırılmış; T-6C Texan II'nin yapısına uygun olarak mekanik kontrol sistemi tercih edilmiştir. Tork tüpüne etki eden yüklerin belirlenmesinde, EASA (Avrupa Havacılık Emniyet Ajansı) tarafından hazırlanan CS-23 tip sertifikasyon kuralları temel alınmıştır. Bu kurallar çerçevesinde, pilotun uygulayabileceği maksimum kuvvetler belirlenmiştir. Referans uçağın dümen kontrol sistemine ait teknik verilerin üretici tarafından paylaşılmaması nedeniyle, literatürdeki benzer sistemler incelenerek pedal, kollu mafsal, çelik halat ve tork tüpten oluşan bir konsept geliştirilmiştir. Konseptin basitleştirilmesi sonucunda, tork tüp üzerindeki yük dağılımını modellemek amacıyla bir yük diyagramı oluşturulmuştur. T-6C Texan II'nin yandan ve üstten görünümleri kullanılarak, Excel üzerinde ölçeklendirme yapılmış; pedal mesafeleri, tork tüp uzunlukları gibi parametreler hesaplanmıştır. Ön tasarım aşamasında, tork tüp ile kollu mafsal dişlilerle birleştirilmiş; tüpün kök kısmı dümen kaburgasına (ribine) bağlayıcılarla sabitlenirken, diğer ucu dana gözü yatak üzerinden iki çerçeve arasındaki yapıya bağlanmıştır. Statik olarak belirsiz olan sistemin analizi için üç bölgeye ayrılan bir kiriş modeli oluşturulmuştur ve MATLAB ile statik denge denklemleri çözülmüştür. Kesme kuvveti ve eğilme momenti diyagramları elde edilerek maksimum Von Mises gerilmeleri hesaplanmıştır. Ayrıca, ISO 6336-3:2006 standardına uygun olarak dişli kök gerilmeleri analiz edilmiştir. İnce cidarlı yapılarda kritik bir faktör olan burkulma-burulma etkisi, NASA (Ulusal Havacılık ve Uzay Dairesi)'nın metodolojisi kullanılarak incelenmiştir. Tork tüpün burulma açısının 4 dereceyi aşmaması için matematiksel hesaplamalar MATLAB ile yapılmıştır. Malzeme seçiminde havacılık endüstrisinde yaygın kullanılan Alüminyum 7050 T7451 tercih edilmiştir. Optimizasyon sürecinde genetik algoritma yöntemi kullanılarak hacim minimizasyonu hedeflenmiştir. Tasarım değişkenleri olarak iç-dış yarıçaplar, dişli parametreleri ve geometrik sınırlar belirlenmiş; Von Mises gerilmesi, burkulma açısı ve imalat kısıtları gibi parametreler göz önünde bulundurulmuştur. Optimizasyon sonucunda tork tüpün kesit profili ve dişli geometrisi optimize edilmiştir. Detay tasarım aşamasında, bağlayıcıların eksenel ve kayma gerilmeleri Excel ile hesaplanmış; iterasyonlar sonucunda emniyetli bağlantı konfigürasyonu belirlenmiştir. Dana gözü yatağın teknik dokümanlarındaki dayanım değerleri rulmana etki eden yükler ile karşılaştırılarak emniyetli olduğu gösterilmiştir. CATIA ile detay olarak modellenen tork tüp, HyperMesh aracılığıyla sonlu elemanlar modeline dönüştürülmüş; NASTRAN ile yapılan analizlerde analitik sonuçlarla tutarlılık sağlanmıştır. Sonuç olarak, temel eğitim uçakları için emniyetli ve optimum bir tork tüp tasarımı ortaya konulmuştur.
Özet (Çeviri)
Numerous aircraft have been designed in aviation from the past to the present. Each of these designs varies according to the aircraft's mission, the customer's requirements, the manufacturer's production capacity, and the established budget. The engineer's task is to propose the most suitable design under all these conditions. Basic training aircraft, which have played a significant role in pilot instruction from the past to the present, exhibit a wide range of configurations. One of the fundamental distinctions determining these configurations is the pilot seating arrangement, which affects the dimensions of the fuselage, tail, and wings. Although the aircraft design seemingly comprises basic components such as wings, fuselage, and tail when viewed externally, numerous internal systems are necessary to ensure the aircraft can fulfill its mission safely. One such system, the flight control systems, is divided into primary and secondary control systems. Primary control systems ensure the safe maneuvering of the aircraft, while secondary control systems aim to reduce the pilot's control workload. Among the primary control systems, the rudder control system stands out as one of the most critical. The fundamental function of the rudder control system is to enable the pilot to control the aircraft's yaw motion by pressing the rudder pedals. A key structural element of this system, which links it to the rudder, is the torque tube. The objective of this study is to develop an optimal torque tube design for a basic training aircraft. The study begins with a literature review. After defining basic training aircraft, the characteristics of rear-seated training aircraft—such as length, wingspan, and maximum takeoff weight—were examined among those found in the literature. Among the examined aircraft, the T-6C Texan II was selected as the reference aircraft. Primary and secondary flight control systems were discussed. The basic operating principle of the rudder control system, which is one of the primary control systems, was explained. Among mechanical and electronic rudder control systems, the mechanical control system was selected conceptually as the most suitable for the T-6C Texan II. Since the T-6C Texan II was taken as the reference aircraft, the loads acting on the rudder torque tube were determined with reference to the CS-23 certification rules prepared by EASA (European Union Aviation Safety Agency) for normal, aerobatic, general aviation, and commuter aircraft. The relevant CS-23 clauses concerning pilot-applied forces were then examined. These clauses state that aerodynamic loads and the resulting deflections on movable surfaces must not exceed the forces that pilots can apply. Therefore, when determining the loads acting on the rudder torque tube, the pilot forces specified in the relevant CS-23 clauses were taken into account. In line with these clauses, the maximum forces that can be applied by a single pilot and by two pilots were calculated using appropriate factors. Because the manufacturer did not provide information on the rudder control system of the reference aircraft, a conceptual design composed of the pedals, bellcrank, steel cable, and torque tube was developed by examining rudder control systems in the literature. This concept was simplified to establish a load model to determine the loads acting on the torque tube. In sizing this model, the side and top views of the T-6C Texan II were used. The side view of the aircraft was transferred to an Excel worksheet. Using the aircraft's length data, the scale factor for reducing the side view image was determined. The same factor was calculated for the top view of the aircraft using the wingspan. As a result of these calculations, dimensions such as the distance between the front and rear pedals and the distance between the pedals and the torque tube were estimated. Average hip span and average foot width measurements were used to estimate the distance between the pedals. All these values were entered into the relevant cells in the Excel worksheet to obtain the torque and moment values acting on the torque tube. A preliminary design was developed for the rudder torque tube. In the preliminary design, the torque tube is connected to the bellcrank via gears. One end of the tube is attached to the rudder rib by means of connectors, while the other end is connected to a structure that passes between the aircraft frames by a plain bearing. For the strength calculations of the preliminary design, an analytical beam model was constructed. The analytical beam model was examined in three separate regions: the first region from the center of the plain bearing to the gear, the second region where the gear connects to the bellcrank, and the third region from the end of the gear to the point where the torque tube connects to the rudder. Boundary conditions were defined with a simply support at the plain bearing (the end of the torque tube), allowing translational freedom in the x, y, and z axes while constraining rotational freedom in those axes, and with a fixed-clamped support at the root of the tube, which restricts all translations and rotations. Since the load is transmitted from the bellcrank to the tube via gears, the calculated forces and moments in that region were applied as linearly distributed loads. The model is statically indeterminate; hence, equations for solving statically indeterminate systems were used in the analytical solution. The strength calculations for the analytical beam model were performed by coding in MATLAB. First, the code calculates reaction forces and moments using static equilibrium equations. Then, shear force and bending moment diagrams along the rudder torque tube are obtained. In this methodology, the shear forces and bending moments at each section are used to determine the maximum Von Mises stress. The MATLAB code then performs strength calculations for the gear. The ISO 6336-3 standard was referenced to calculate the stress at the gear root where the beam connects to the bellcrank. In thin-walled structures, torsional buckling can be critical. Therefore, the torsional buckling analysis in the MATLAB code was conducted using NASA (National Aeronautics and Space Administration)'s thin-walled cylinder torsion method. This method applies to cylinders of constant thickness with both ends simply supported. Although the model has one end fixed and the other simply supported, the varying wall thickness in each region necessitated a conservative approach. Since the calculation is based on a constant-thickness cylinder, the analysis was performed assuming the entire cylinder is of the minimum thickness, yielding more conservative critical buckling stresses. To prevent the performance of the rudder control system from being affected, the angular twist of the rudder torque tube was kept below 3 degrees. The twist calculation was performed using the torsion formula for beams with variable cross-sections. This calculation was executed with MATLAB code. Commonly used materials in aviation were examined, and Aluminum 7050 T7451 was selected as the material for the torque tube. The strength calculations performed by the MATLAB code were then optimized. To this end, optimization methods in the literature were reviewed, and the genetic algorithm—a global optimization method based on natural selection and genetic operators (crossover, mutation, etc.) —was selected as the most suitable method. The objective function for the optimization was defined as the volume. The optimization code included six constraints: Von Mises stress, angular twist, manufacturability constraints, torsional buckling, gear root stress, and torsional buckling instability. There were nine design variables: the inner and outer radii of each of the three regions, gear length, gear module, and number of teeth. Upper and lower bounds were defined for each design variable. The optimization parameters were explained, and their effects on optimization performance were discussed. After determining the most appropriate optimization parameters, the optimization was carried out using the Global Optimization Tool in MATLAB. The optimization results defined the inner and outer radii of the tube cross-section in each region and the gear profile. For the detailed design of the tube, connector selection was performed using an Excel program. In the connector strength calculations, axial and shear forces acting on each connector were calculated using equilibrium equations. Compression stress, shear stress, and axial strength values were computed. The calculated values were compared with the connector and plate strengths through combined loading analysis. Iterations by changing the number and diameter of connectors were conducted, resulting in the determination of the number of connectors and plate thickness in the region where the torque tube attaches to the rudder. Connector locations and plate diameter were determined by design criteria. It was demonstrated that the strength in this region remained on the safe side. For the selection of the rod-end bearing at the end of the torque tube, the strength values from the technical documents of the bearings were used. These values were compared with the axial and shear froces acting on the bearing to show that the selected bearing was safe. The detailed design of the tube was carried out using CATIA. The final model designed in CATIA was exported as a STEP file and imported into HyperMesh. A three-dimensional finite element model was created in HyperMesh using second order tetrahedral elements for the mesh. Connectors were connected to the tetrahedral elements using RBE2 elements. Forces and moments were distributed to the structure from the center of the gear region via RBE3 elements. Boundary conditions were applied as fixed supports at the ends of the connectors and at the bearing region. After model validation, the solution was obtained using NASTRAN. The finite element model was compared with the analytical model, and the differences were discussed. As a result, it was demonstrated that the structure was safe, thereby presenting an optimal rudder torque tube design for a basic training aircraft.
Benzer Tezler
- Portfolio optimization with wavelet analysis and neural fuzzy networks
Dalgacık analizi ve bulanık sinir ağları modeli ile portföy optimizasyonu
ÖMER ZEKİ GÜRSOY
- Multi-objective optimization of swirl burner with premixed ammonia/hydrogen flame
Ön karışımlı amonyak/hidrojen alevine sahip girdaplı yakıcının çok hedefli optimizasyonu
MEHMET ANIL GÜLŞAN
Doktora
İngilizce
2026
Makine Mühendisliğiİstanbul Teknik ÜniversitesiMakine Mühendisliği Ana Bilim Dalı
PROF. DR. YAKUP ERHAN BÖKE
- Fighter pilot behavior cloning and transferring to another aircraft
Savaş pilotu davranışı klonlama ve farklı bir hava aracına transferi
GÜLAY SEVER
Yüksek Lisans
İngilizce
2022
Havacılık ve Uzay Mühendisliğiİstanbul Teknik ÜniversitesiSavunma Teknolojileri Ana Bilim Dalı
DOÇ. DR. NAZIM KEMAL ÜRE
- Flight safety risk awareness at flight test activities with analytical hierarchy process method
Analitik hiyerarşi süreç yöntemi ile uçuş test faaliyetlerinde uçuş emniyet risk farkındalığı
YUSUF AKGÜR
Yüksek Lisans
İngilizce
2022
Havacılık ve Uzay Mühendisliğiİstanbul Teknik ÜniversitesiUçak ve Uzay Mühendisliği Ana Bilim Dalı
PROF. DR. ALİ KODAL
- Scientific machine learning supported track-to-track fusion
Bilimsel makine öğrenmesi destekli takip bilgisi füzyonu
RECEP AYZİT
Yüksek Lisans
İngilizce
2025
Uçak Mühendisliğiİstanbul Teknik ÜniversitesiUçak ve Uzay Mühendisliği Ana Bilim Dalı
DOÇ. DR. BARIŞ BAŞPINAR