A mobility analysis of using the Rhex-type mobile robot in various surroundings

Mobile robots are becoming increasingly popular, finding a great deal of applications, especially in situations where conventional mobility systems, such as wheels or tracks, prove ineffective. Exploration of an unknown environment or a place, in which Man is incapable of staying, for example exploring remote planets in the Solar System, is often linked with operating a device in a rough terrain. This requires an adjustment of the robot locomotion system to the ground. The problem of high mobility in diverse surroundings is still a major challenge. Therefore, the concept of mobile robots is extremely popular and is still being developed. Using this type of propulsion carries several advantages, namely the possibility of applicability of this type of solutions in an environment, which is not easily accessible to wheeled vehicles (sandy, mountainous terrain, etc.). There is still a large interest of constructors and scientists in unconventional drive systems, adapted directly from nature, which often offers very efficient solutions. Quite frequently, designers copy the construction of animal locomotion system, attempting at implementing them in their designs. The aim of this article is to present an original construction, known as the Rhex-type robot in the available literature. In addition, it presents a number of conducted investigations, which describe the platform’s mobility in various terrains, such as sands, rocks and rubbles, as well as the possibility to overcome the terrain obstacles. It ends with conclusions and potential application areas of this type of a design

The analysis of the properties of ablative composites with carbon and MMT nanofiller reinforcement

One of the most important parameters in the selection of composite materials used for the protection of avionics instruments exposed to high temperatures are ablative properties. They constitute the main criterion in determining the composition and thickness of the protective material. In this article, the authors determine the ablative properties of a polymer matrix with carbon reinforcement and check the effect of using the MMT additive (montmorillonite) on the change in the resistance to the impact of a high heat flux. The tested materials play an important role in the defence, aviation and space industry. Ablative materials are the only ones to protect the rear wall surface from an excessive temperature rise while using a thin insulation wall. For the sake of the research, we prepared a series of samples of the composite produced with epoxy resin LH 145, H 147 hardener, carbon fibre mats and the addition of MMT. The prepared samples were tested on a unique stand in laboratory conditions. The findings obtained from the experimental testing after a detailed analysis were tabulated and presented in the form of graphs. The authors determined the ablative loss of mass of the individual samples, compared their internal temperatures, which had been measured with thermocouples, as well as the temperature on the backside of the sample. In addition, in order to complement the experimental studies of determining the temperature rise on the rear surface, the authors used a thermal imaging camera. Besides, they took photos of different layers of the examined structure, which had been exposed, to a heat stream, by means of a scanning microscope

FCFD analysis of the influence of winglets on the aerodynamic performance of the DA42 Diamond aircraft

The paper presents the application of Computer Aided Engineering software for an investigation of the aerodynamic performance of a small two-engine aircraft. In the presented study, the Computational Fluid Dynamics was applied in order to determine the influence of winglets on the aerodynamic performance of the DA42 Diamond aircraft. The numerical simulations were performed with the use of SolidWorks Flow Simulation software. In order to evaluate the influence of the winglets on the lift and drag force, two configurations of the selected aircraft were modelled: with and without winglets. The results of CFD simulations confirmed a reduction of induced drag caused by wingtips vortices dissipation introduced by winglets. The maximum reduction of the induced drag was achieved at high angles of attack. The authors visualized the structure of vortices in case of wings with and without winglets. A smaller volume of wingtip vortices in case of winglets application can be seen in the pressure distribution and streamline plots. The outcome of the presented work confirms the feasibility of Computer Aided Engineering for the assessment of aerodynamic performance of aircraft. The presented methodology can be used in the process of designing and optimisation of alternative configurations of aircraft. The results of work might prove useful for DA42 DIAMOND pilots and maintenance personnel as well as for educational purposes

FCFD ANALYSIS OF THE INFLUENCE OF WINGLETS ON THE AERODYNAMIC PERFORMANCE OF THE DA42 DIAMOND AIRCRAFT

The paper presents the application of Computer Aided Engineering software for an investigation of the aerodynamic performance of a small two-engine aircraft. In the presented study, the Computational Fluid Dynamics was applied in order to determine the influence of winglets on the aerodynamic performance of the DA42 Diamond aircraft. The numerical simulations were performed with the use of SolidWorks Flow Simulation software. In order to evaluate the influence of the winglets on the lift and drag force, two configurations of the selected aircraft were modelled: with and without winglets. The results of CFD simulations confirmed a reduction of induced drag caused by wingtips vortices dissipation introduced by winglets. The maximum reduction of the induced drag was achieved at high angles of attack. The authors visualized the structure of vortices in case of wings with and without winglets. A smaller volume of wingtip vortices in case of winglets application can be seen in the pressure distribution and streamline plots. The outcome of the presented work confirms the feasibility of Computer Aided Engineering for the assessment of aerodynamic performance of aircraft. The presented methodology can be used in the process of designing and optimisation of alternative configurations of aircraft. The results of work might prove useful for DA42 DIAMOND pilots and maintenance personnel as well as for educational purposes

Wizualizacja przepływu wokół modelu skrzydła z mechanizacją w tunelu wodnym

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.W pracy przedstawiono uzasadnienie możliwości zastosowania tunelu wodnego do wizualizacji przepływu modeli profili lotniczych z mechanizacją w postaci slotów i klap. Ponadto przybliżono tematykę zastosowania tuneli wodnych w celach naukowych jak i szkoleniowych. Przedstawiono również technologię wydruku 3D modeli do testów praktycznych w tunelu wodnym. Eksperyment obejmował przeprowadzenie badań wizualizacyjnych dla trzech modeli profilu lotniczego: jako bazowy profil Clark Y 11.7% oraz ten sam profil ze slotem i z klapą. Ponadto autorzy pracy wprowadzili modyfikację wprowadzania barwnika przed badany model geometryczny umiejscowiony na trzymaku w przestrzeni pomiarowej. Przedstawione wyniki zobrazowania przepływał w:okół modeli za pomocą barwnika potwierdziły skuteczność zastosowanej metodyki prowadzenia eksperymentu na charakterystycznych kątach natarcia. Wyniki i wnioski można wykorzystać do zweryfikowania większości zagadnień przepływowych w tunelach hydrodynamicznych jak również mogą posłużyć jako element szkoleniowy