Test rig dedicated for hardware used in wind tunnels

The paper present the results of work on measurement system dedicated to hardware used during wind tunnel tests, especially to servomechanisms. These devices could be applied to set specific position of control surface. Proposed system would ensure continuous monitoring of servo-rotor position and servo-motor temperature and would avoid uncontrolled change of control surface position. The application designed to monitor the operating status of the servomechanism was prepared in the LabVIEW software and was implemented on the myRIO platform. Developed test rig allow to register time histories of servo-rotor position and temperature during for different values of applied load. In the paper, test methodology were also presented. Experimental studies show that before wind tunnel tests, selected servomechanism should be tested in terms of maintaining the parameters declared by the manufacturer, especially during continuous operation. Developed measurement system can be used during wind tunnel tests, as well as only for servo-mechanism parameter testing.

The advanced CAD model of a cargo bike

This article describe a way to create generative model at the example of cargo bike model, which is very simple object which can be used to present all important rules applied during crating generative models. Great attention was paid to the issue of model parametrization which is elementary thing in all modelling. Besides these aspects, it is also shown how to transform parametric model into generative model using programming languages. In the last part of article was included tests of correct working of model which focused also to the right position cyclist on the bike and shows how model of cargo bike could change its sizes thanks to correctly created generative model.

Numerical Simulation of Flow Through Microchannels with Random Roughness

The aim of the study is to determine the effect of a randomly generated rough surface on the laminar flow of a fluid in a microchannel. Two-dimensional axially symmetric microchannels with a circular cross-section in the range of Reynolds number Re = 100-1700 were considered. Flow numerical simulations were performed using the Ansys / Fluent software.

Pseudo-random number generator based on linear congruence and delayed Fibonacci method

Pseudo-random number generation techniques are an essential tool to correctly test machine learning processes. The methodologies are many, but also the possibilities to combine them in a new way are plenty. Thus, there is a chance to create mechanisms potentially useful in new and better generators. In this paper, we present a new pseudo-random number generator based on a hybrid of two existing generators - a linear congruential method and a delayed Fibonacci technique. We demonstrate the implementation of the generator by checking its correctness and properties using chi-square, Kolmogorov and TestU01.1.2.3 tests and we apply the Monte Carlo Cross Validation method in classification context to test the performance of the generator in practice.

Influence of Geometric Features Associativity of CAD Class Models on the Process of Their Updating – Comparative Analysis

This article deals with the topic of one of the most important features of modern CAx class systems – associativity. The term refers to the ability to form relations (links) between two or more objects (in terms of their selected features), and with the consequence creating an associative (linked) three-dimensional model. The author pays special attention to the very process of creating relations between objects, as it has a key impact on the structural stability of CAD class models, and thus on their susceptibility to possible modifications. To show that not all associativity brings a positive effect, the author presents two examples of its implementation. In order to emphasize the influence of the method of linking individual elements, both examples are based on the same 3D model – a thin-walled part with a positioning pin. That means the geometric form of the default part is the same, whereas only relations of the individual objects of the 3D model change. In the first scenario, correctly defined relations between objects make that the positioning pin offset does not affect the initial design conditions. The second scenario shows an incorrect implementation of associativity, as a result of which the same operation of positioning pin offset gives non-compliance with the initial design conditions and with the consequence an undesirable change in its geometry. The article is an attempt to draw attention to the fact that the associative structure of 3D models is not always equal to the optimal solution. Only the well-thought-out nature of associativity allows to use all its advantages.

Influence of Various Methods of Modelling the Welding Process in the CAE Environment nn the Obtained Deformation Results

By simulating the welding process, potential non-conformities can be detected before serial production is launched, which can significantly reduce operation costs. There are many different possibilities for modeling the process, therefore it is very important to choose a method that will ensure high accuracy of the solution in a relatively short time. The article will present the influence of various methods of modeling the welding process in the CAE environment on the obtained deformation results. For the given geometry and type of weld, the thermal deformations have been simulated based on the Finite Element Method. Several analyzes were carried out using different process modeling approaches (mesh type). Finally, a comparison of the results for the discussed cases is presented to determine the influence of the parameters used on the deformation results obtained.

Simulation Study of a Composite Landig Gear of Ultralight and Very Light Aircraft

There is a need to design new, lighter aircraft structures, which has a direct impact on the safety and costs of aircraft maintenance. One of basic parts of an aircraft is ites landing gear, whose main functions are to enable taxiing, safe landing, take-off, and to assist the remainder of ground operations. Landing gear failures are usually related to metallurgy, processing, environment, design, and causes of overload. These are conditions that can be prevented using modern methods to calculate the strength of such a landing gear in various conditions. The paper presents stages of a simulation study of the fixed three-wheeled spring landing gear for an ultralight aircraft. Analysis of forces acting on the landing gear during drop test and their implementation by numerical computer methods allowed for the creation of a model in the CAD (Computer-Aided Design) tool and its FEA (Finite Element Analysis). These results were compared between a modeled classic spring landing gear and the one made of composite materials. The further goal of the research will be to build a drop test stand for a small landing gear used in airplanes and drones. This method has a significant impact on simplifying the design of the landing gear, its modeling, and optimization.

Sniper Rifle Cartridge

The paper proposes a modification of the 7.62 mm NATO rifle cartridge. The design and the results of a computer simulation were presented. The projectile’s flight behavior under different weather conditions was simulated. A figure diagram and a digital model of the projectile were presented. Ballistic calculations were performed, and an animation showing the projectile’s behavior under various weather conditions was developed. The results were patented.

Tribological wear of Fe-Al coatings applied by gas detonation spraying

Comparative tests of gas detonation (GDS) coatings were carried out in order to investigate the influence of spraying parameters on abrasive wear under dry friction conditions. The tests were carried out using the pin-on-disc (PoD) method at room temperature. The microstructure of the coatings was analysed by X-ray diffraction (XRD) and scanning electron microscopy (SEM / EDS) methods. The results showed that with specific GDS process parameters, the main phases in both coatings were FeAl and Fe3Al involving thin oxide films Al2O3. The tribological tests proved that the coatings sprayed with the shorter barrel of the GDS gun showed higher wear resistance. The coefficient of friction was slightly lower in the case of coatings sprayed with the longer barrel of the GDS gun. During dry friction, oxide layers form on the surface, which act as a solid lubricant. The load applied to the samples during the tests causes shear stresses, thus increasing the wear of the coatings. During friction, the surface of the coatings is subjected to alternating tensile and compressive stresses, which lead to delamination and is the main wear mechanism of the coatings.

Modelling and simulation of functioning of the GSh-23 aviation autocannon mechanisms

Article presents the simulation model and the study of the basic mechanisms of the GSh-23 aviation autocannon. The research made use of Solid Edge ST9 software and the multibody systems method implemented in it. Simulation of functioning cannon mechanisms was carried out for two variants of forcing a piston mechanism movement by the gunpowder gases. The results obtained are time courses of a bolt and a cartridge belt drive mechanism elements movement. Assumed variants of a piston mechanism movement and elaborated simulation model will be verified in the next (planned) stage of studies basing on the results of the measurements of the experimental kinematic parameters utilising high-speed camera (Phantom) and TEMA software.