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An Unmanned Aircraft Model for Control System Reconfiguration Analysis and Synthesis

Abstract

Reliability of unmanned aircraft is a decisive factor for conducting air tasks in a controlled airspace. One of the means of improving unmanned aircraft reliability is reconfiguration of the control system, which will allow to maintain control over the aircraft despite an occurring failure. The control system is reconfigured by using still operational control surfaces to compensate for failure consequences and to control the damaged aircraft. Development of effective reconfiguration algorithms involves utilization of a non-linear model of unmanned aircraft dynamics, in which each control surface deflection can be controlled independently.

The paper describes a non-linear model of a small unmanned aircraft with decoupled control surfaces. The paper discusses aircraft flight dynamics equations and estimated equations for controllability derivatives for each control surface, the results of comparison tests of the model and actual aircraft as well as the structure of the simulation model. The developed unmanned aircraft model may be used in development and in optimization of control algorithms for aircraft with damaged control systems as well as to test the impact of failures on dynamic properties of the aircraft.

Open access
Analysis of Heat Transfer in a Supersonic Rocket Head

Abstract

Design of supersonic H1 rocket by the Rocketry Group of Students’ Space Association (SR SKA) requires an analysis of thermal phenomena occurring in the elements particularly exposed to the high temperature gas. This paper contains a description of the methodology and the results of numerical simulation of heat transfer in the elements of the rocket head. The starting points were the flight conditions (3 characteristic points defined by altitude and Mach number) and independently calculated adiabatic temperature field of the gas. ANSYS Fluent code was used to determine the temperature field on the surface of the rocket. Computed cases were viscous and inviscid flow (for comparison). Based on the results formulated for the viscous case heat transfer boundary conditions, the numerical model and the thermophysical properties of materials were defined. The model was limited to a brass top part of the head and a part of a composite dome. Analytical and empirical method of “intermediate enthalpy” determined distribution of the heat transfer coefficient on the rocket surface. Then the transient heat transfer was calculated with the ANSYS system. It included the range from the rocket launch, moment of maximum Mach number to sufficient structure cooling. The results of the analyses were conclusions relevant to the further development work. Excessive heating of composite structures during the flight has been shown.

Open access
Flow Visualization Over an Airfoil with Flight Control Surfaces in a Water Tunnel

Abstract

This paper demonstrates the feasibility of using-a water tunnel for the visualisation of flow in airfoils with flight control systems in the form of slots and flaps. Furthermore, the issue of using water tunnels for scientific and training purposes was explained. The technology of 3D printed models for practical tests in a water tunnel was also presented. The experiment included conducting flow visualisation tests for three airfoil models: with the Clark Y 11.7% as the base airfoil and the same airfoil with a slot and a flap. Moreover, a modification to dye injection system was introduced. The presented results of flow visualisation around models with the use of dye, confirmed the effectiveness of the applied methodology. The results and conclusions may be utilized to verify most flow-related issues in hydrodynamic tunnels and can also be used as a training element.

Open access
Importance of Personal Data Protection Law for Commercial Air Transport

Abstract

In the review below the author presents a general overview of the selected contemporary legal issues related to the present growth of the aviation industry and the development of aviation technologies. The review is focused on the questions at the intersection of aviation law and personal data protection law. Massive processing of passenger data (Passenger Name Record, PNR) in IT systems is a daily activity for the contemporary aviation industry. Simultaneously, since the mid- 1990s we can observe the rapid growth of personal data protection law as a very new branch of the law. The importance of this new branch of the law for the aviation industry is however still questionable and unclear. This article includes the summary of the author’s own research conducted between 2011 and 2017, in particular his audits in LOT Polish Airlines (June 2011-April 2013) and Lublin Airport (July - September 2013) and the author’s analyses of public information shared by International Civil Aviation Organization (ICAO), International Air Transport Association (IATA), Association of European Airlines (AEA), Civil Aviation Authority (ULC) and (GIODO). The purpose of the author’s research was to determine the applicability of the implementation of technical and organizational measures established by personal data protection law in aviation industry entities.

Open access
The Influence of the Fastener Hole Preparation Method on the Fastener Pull-Through Process in a Carbon Composite

Abstract

This article studies the pull-through resistance of a titanium carbon fibre-epoxy resin laminate fastener. Coupons with fastener holes made with different methods were compared – drilled, milled on a CNC plotter and special fibre application during laminate production. The tests were conducted according to the ASTM D7332 test standard. The studies showed that the fastener hole preparation method impacts the laminate’s resistance to fastener pull-through. Coupons with holes made with standard (drilling and milling) methods showed fastener pull-through resistance higher, on average, by 6.5% than in coupons with holes placed during plate production. Fastener work to rupture was also higher for coupons with milled and drilled holes. Microscopic observations in UV-light, using a fluorescent penetrant, showed differences in failure mechanisms between individual coupons, especially the lack of fibres in the 0° direction, in immediate vicinity to a hole prepared during laminate application.

Open access
The Life Cycle of a Training Project in a Research and Development Unit

Abstract

The article describes the life cycle of a training project in a research and development unit, from setting the training target, through analyzing the needs of the group, establishing workshops’ programs and logistics, up to the evaluation and implementation support. The role of human capital has been presented in the article, thus the need for training organization has been demonstrated to improve quality of work. The article also describes characteristics of the training market, defining types of projects addressed to representatives of the most often trained groups in the research and development unit, like professionals, managers and research workers. Methods and tools aiding the training system analysis and monitoring have also been introduced in the text with a goal to reflect customer, employer, and trainee satisfaction. A process of raising qualifications of employees was described at the Institute of Aviation. It has been found that internal trainings from the subject matter of “project management” are the best solution for research and development centers.

Open access
Mechanical Properties of the Package of Ferromagnetic Sheets

Abstract

The paper presents the measurement method and results as well as the results of comparative calculations aimed at determination of material data for the package of ferromagnetic sheets insulated with epoxy lacquer. During the test, the package of sheets was treated as a 3D orthotropic material. The values of Young’s and Kirchhoff’s moduli for a pre-compressed package of sheets, in accordance with the used manufacturing technology of the medium and high power electric motors’ rotors, were detennined. The carried out FEM comparative calculations confirmed that the determined mechanical parameters of the package of sheets as a 3D orthotropic material, i.e. Young’s and Kirchhoff’s moduli, for the compressive stress range of 1.0÷2.5 MPa, are included in the linear range. It was assumed that the determined mechanical properties of the package of sheets are necessary at the design stage for FEM simulation calculations of the electric motors’ vibration and strength properties. As a result of the tests, it was found that they should be repeated in order to determine the properties of other sheets or those coated with different insulating lacquer.

Open access
Process of Preparing and Laying Carbon Prepregs

Abstract

This article contains information on the technological process involved in the production of a composite structure with carbon-epoxy prepregs including critical parameters of the process. The information in the publication shows respectively:

1. Using composite components for constructing the airframe,

2. ways of storing and preserving carbon prepregs on a matrix of thermosetting resins,

3. specific types of varying weave fabrics used in the prepregs,

4. way of preparing material for the process,

5. cutting tools,

6. preparing swage,

7. list of the most popular materials, their characteristics, pros and cons of their applications,

8. issues related to types of release agent,

9. parameters of selecting release agents in the process of manufacturing structures with carbon prepregs,

10. process of laying plies in a layered structure,

11. defects which result from improper material laying in swage,

12. preparing the structure for heating and technical parameters of the process.

Open access
Quality Control Process of Manufactured Composite Structures

Abstract

The paper includes a description of the composite material used in the aviation industry. It presents the technological development of composites in terms of their use in the most important elements of the aircraft structures, such as a spar and aircraft wing sheathing, which are subjected to high loads during operation. The type of the material implemented for production was listed and the most commonly occurred incompatibilities during the carbon pre-impregnate manufacture and transport were described.

The manufacture diagram of composite elements with a polymer matrix was presented and the quality control system carried out at each mentioned stage (material storage, defrosting, cutting of dies, structure forming, polymerisation) was discussed.

The methods of non-destructive tests of carbon laminates in a polymer matrix were also listed, describing the most effective of them, i.e. a method of ultrasonic tests.

The conclusions were drawn and the development possibilities of ultrasonic tests both in terms of quality improvement and reduction of time for detecting incompatibilities in composite structures were described.

Open access
Research of Dependence of the Damage Area on Tow Width on Filament-Wound Composite Tubes

Abstract

This paper explores the effect of tow width on the damage area produced by high velocity impacts on glass fiber/epoxy composite structures made by filament winding. The subject of the research were a four-layered composite tubes that have been designed using matrix method. The method was used to select mosaic patterns with different rest of the winding stroke and number of interlaces, which are places of stress concentration and which affect the strength of the composite. The narrowest (5 mm) and the widest (17 mm) tow width available was chosen. Composite filament-wound structures were subjected to a high velocity impact by a 2.0 g spherical hardened steel impactor propelled to a velocity of 140 ÷ 170 m/s using a gas gun. It was observed that dependence of the damage area on tow width on filament-wound composite tubes is possible.

Open access