Winglets being a small structure play an important role in reducing the induced drag in aircraft. Many types of winglets have been designed and their significance in reducing the drag is published. One of the main objectives of this master thesis work is to study about the winglet design and about their contribution in reducing induced drag. A brief overview of wing tip devices and their performance from the manufacturers as well as from airliner’s point of view are discussed. Moreover, the role of winglet in reducing the drag of commercial civil jet aircraft is studied and the percentage of drag reduction is calculated by a conceptual approach. A320 specifications are taken to perform induced drag reduction calculation with and without winglets. Indeed, the total drag count reduced with the help of winglets accounts for additional payload which will be an advantage for the aircraft operator. Reducing the process time in design is one of the important criteria for any field and hence automation with help of CAD tools is very significant in reducing time. This study also aims at developing an automated model for different types of winglets and wing tip devices with the help of CAD technology focused on reducing design time during the initial design process.  Knowledge based approach is used in this work and all the models are parameterized so each model could be varied with associated parameters. The generic model created would take different shapes and switches between different types of wing tip devices as per the user’s requirement with the help of available parameters. Knowledge Pattern (KP) approach is used to develop the automation process. User Defined Features (UDFs) are created for each type of winglet and tip devices. CATIA V5 R18 software is used to develop the models of winglets and tip devices.

This thesis work presents a parametrized integration of the flight control system within RAPID by means of the automation in CATIA V5, using Knowledge Pattern. Nowadays aircraft’s design and development processes are not only time-consuming but also incur high economic cost. In addition, system integration is highly a multi-disciplinary design process which often involves a large number of different discipline teams working at the same time and space. The main objective of this thesis is to investigate how CAD (Computer Aided Design) software can be used in the early design stages to define the flight control system integration. The purpose of this work to improve the functionality of an in house produced aircraft conceptual design tool carried out at the Division of Fluid and Mechatronic Systems, Linköping University. The work consists of preliminary integration of the RAPID flight control system and the hydraulics associated to it. By defining several reusable templates, the automatic definition of a flight control system within the RAPID aircraft has been achieved. Moreover it is a parametrical model which allows the user to modify a high number of features as desired to enhance the design process. For this, a user interface in Microsoft Excel connected to CATIA has also been attained.