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  • Author: Robert Babel x
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Abstract

The aerodynamic research into models of an aircraft aims at creating the main characteristics of aerodynamic forces and moments and the aerodynamic characteristics of coefficients of aerodynamic forces and moments, based on real dimensions. The method of 3D printing was used to create a model of an aircraft. The model with the previously set printing parameters and commands for a 3D printer, in the right order, was imported into MakerBot Print. The final stage was printing the model. The printed components of the model of an aircraft were imperfect due to the incorrectly set printing parameters. The model with the previously set printing parameters and commands for a 3D printer, in the right order, was imported into MakerBot Print. The final stage was printing the model. The printed components of the model of an aircraft were imperfect due to the incorrectly set printing parameters. The printing parameters were corrected in the next printing sessions so the surfaces of the components were good enough and grinding was unnecessary. Some excess material was removed in each of the printed components, and the slots were cleaned. Then, the individual models were put together.

The article describes the technique of creating a model of an aircraft to map its exact geometry for experimental wind tunnel research. 3D printing enables us to experimentally investigate a created geometry, in particular to investigate further prior to releasing an aircraft to service. The 3D model employs the model created in line with the previous CFD analysis.

Abstract

The article presents investigation of flow around wing of TS-11 Iskra airplane. The flow visualization around 3D printed model of wing with flow control surfaces was performed in a water tunnel. Two configurations were investigated: first with a flap and second with an aileron. The flow visualisation was performed with a use of a dye. The geometry of model was prepared with use Computer Aided Design (CAD) software basing on scans of real object and technical documentation. The model was built with use of additive manufacturing technology. Movement of the flow control surfaces was remotely controlled with servomechanisms incorporated in channels inside the model. In order to perform qualitative validation of the results the investigated flow was simulated with use of CFD commercial software. The article presents visualisation results of flow around wing section of TS-11 Iskra airplane and water tunnel model preparation. In order to perform qualitative validation of the results the investigated flow was simulated with use of CFD commercial software. The goal of the research was to investigate the complex flow field in the vicinity of flow control surfaces and provide aerodynamic characteristics at various deployment angles via numerical simulations. The results can be used for verification of water tunnel testing procedures and training.

Abstract

The wing is the main aircraft construction element, whose main task is to produce the lift, balancing the aircraft weight as well as ensuring the execution of all flight states for which the aircraft was designed. The selection of appropriate airfoils or the development of new ones is one of the most important constructions goals. As a rule, constructors aim at ensuring a sufficiently large lift with little aerodynamic drag in order to increase the scope of utility angles of attack and such shaping of these characteristics so that the aircraft performance, close to the critical angles of attack, guarantees an adequate level of safety. One of the methods of improving the aerodynamic properties of airfoils is the Kline-Fogleman modification. It involves an application of a step into the airfoil contour at a place. It enforces the creation of a swirling air stream, preventing the separation and maintaining airflow over the profile and thus the reduction of drags, as well as delaying separation. The use of this type of a solution is justified when designing unmanned aerial vehicles, of small sizes, which move with slow speeds and sometimes-large angles of attack, including those close to critical angels of attack. The Kline-Fogleman modification decreases the likelihood of aircraft stalling.

The aim of this work is to present an analysis of airflow over NACA0012 airfoil with Kline-Fogleman modification. The calculations were made by solving the problem of numerical fluid mechanics. For calculations, the Comsol Maribor programme was used. The investigation focused on several different airfoil modifications (KFm-1, KFm-2, KFm-3). This enabled a selection of a solution, providing the most desirable aerodynamic characteristics.

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.

Abstract

The aim of this article is to present findings concerning the thermo-protective research into ablative materials. The authors analysed the impact of the addition of carbon nanotubes upon the selected ablation properties, i.e. the ablation mass waste, average linear rate of ablation and the backside temperature of the specimens. The performed tests as well as the obtained findings allowed formulating a number of conclusions, which are useful in creating future composites.

Composition of individual test samples; ablation testing; average relative ablation mass loss, depending on the volume share of carbon nanotubes; average ablation rate, depending on the volume share of carbon nanotubes; temperature of the rear surface of the insulating sample, depending on the volume share of carbon nanotubes; temperature inside the composite, depending on the volume share of carbon nanotubes; comparison of the temperature of ablation surface, temperature inside the composite and temperature on the rear surface of the wall of carbon nanotubes after the exposition to a heat flux are presented in the article.