Military University Of Technology Research Articles

Studying the Effectiveness of Shaped Charge Jets Created by Graphene-containing Shaped Charge Liners

The paper presents selected results of studies conducted within the framework of the following research project: “Use of graphene and new multilayer explosive technologies in materials for shaped charge liners" (The National Centre for Research and Development in Poland: project No: DOB-BI08/03/01/2016). This study was performed by a consortium made up of the following entities: Institute of Precision Mechanics, Military University of Technology and the Mototechnika company (Poland). The main objective of the performed experiments was to test the effectiveness of shaped charge liners produced with the use of powder metallurgy methods, from mixtures containing copper powder and graphene-coated copper powder. The content of the latter equaled 0%, 1%, 5% and 10%, respectively. Shaped charge jets created with the use of liners made from the powder mixtures tested were recorded with the help of X-ray technology. Firing tests were conducted against steel barriers and the depth of penetration was determined. The obtained results showed that the addition of graphene powder to pure copper powder practically does not increase the depth of penetration of the shaped charge jet compared to scenarios in which sintered liners without this additive were used.

A Preliminary Assessment of the Effectiveness of Training Using a Virtual Reality Simulator of the Anti-aircraft Missile Launcher

Training an anti-aircraft soldier is expensive, complicated, and time-consuming. As a result, many countries, weighing the cost-effectiveness, opt to introduce solutions aimed at minimizing this trend. One of them is incorporating modern training devices such as simulators and trainers into the training. However, to make this happen, it is worth analyzing the effectiveness of training with their use by comparing it to that conducted in a traditional way. With this in mind, the purpose of this article is to present the results of research on the effectiveness of using a Virtual Reality (VR) simulator developed at the Military University of Technology in teaching the construction and basic activities of combat work in the area of conducting a selected check of the functioning of the SA6 Gainful missile launcher system. The theoretical foundation for the empirical research was provided by a method of analyzing literary content. By using the method of comparison and generalization, knowledge was obtained about the general construction and use of training devices in the training of the anti-aircraft defense forces of the Polish Armed Forces, and the features of the VR simulator were described. As regards the empirical methods, a study was conducted using a research sample which was conducted using a parallel triangulation strategy scheme involving the simultaneous use of quantitative and qualitative methods. The synthesis served in formulating the final conclusions and in determining the relationships between theoretical and empirical studies. The results obtained in this way can provide valuable information about the effectiveness of using training devices in training anti-aircraft defense forces and serve as a basis for further work on their development and application.

Experimental Determination of the Dependence Between Spectral Response and Current–Voltage Characteristics for MWIR HgCdTe Detectors

Experimental results are reported for a medium-wavelength infrared (MWIR) HgCdTe photodetector designed in a joint laboratory run by VIGO Photonics S.A. and the Military University of Technology. The parameters of the MWIR detectors fabricated with HgCdTe heterostructures were studied. Advances in the metal–organic chemical vapor deposition (MOCVD) technique enable the growth of HgCdTe epilayers with a wide range of composition and doping, used for uncooled infrared detectors. Device-quality HgCdTe heterostructures were deposited on 2-inch-diameter, low-cost (100) GaAs substrates. The heterostructures obtained were examined measuring the spectral response and current–voltage characteristics in different temperatures. Our intention here was to determine the relationship between electrical and optical results, using thermal analysis of dark current properties and photocurrent and spectral characteristics. The appearance of an additional signal source in certain ranges of reverse voltages was examined. Comparative analysis of the electrical and electro-optical characterization enabled us to isolate the photocurrent originating from different layers of the detector structure. Automated measurement techniques make it possible to correlate current responsivity with current–voltage curves measured as a function of temperature in a range from 10 K to 300 K with ±0.05 K resolution without human exertion. LabVIEW-aided data acquisition enables the averaging of each characteristic several hundred times, eliminates random and human errors, and decreases measurement uncertainty.Graphical

Study of a vertical gravity gradient at the MUT area

Any object on the globe, in addition to the gravitational force, is affected by the force associated with the rotation of the Earth, i.e., the centrifugal force, which together define the force of gravity. Due to various factors, both external (the influence of other celestial bodies) and internal (the inhomogeneous internal structure of the Earth), the gravity depends on the location and time of observation. The study on gravity is made possible by using extremely sensitive measuring devices called gravimeters, which are a branch of physical geodesy called geodetic gravimetry. Geodetic gravimetry is widely used in geodesy to study the shape of the geoid and the realisation of gravimetric control networks or in geophysics to detect mineral deposits, underground watercourses or caves. However, in order to obtain reliable results, it is necessary not only to measure the gravity accurately, but also to reduce these measurements adequately. This is possible by determining, among other things, the vertical gravity gradients (VGG), which are used to reduce the measured gravity values to any reference level. In our research, we focused on analysing the change in the value of VGGs in the closed area of the Military University of Technology (MUT). We used 33 points of the existing vertical and horizontal networks of the MUT for measurements. We performed the observations using ZLS Burris model B-67 spring gravimeter at several heights in the range of 0.1 m to 1.3 m using a specially constructed tripod. We showed that the values of the vertical gradients vary over the selected area from ‒0.2534 mGal/m to ‒0.3917 mGal/m. The obtained results show consistency with the spatial distribution of changes of the topography of the terrain, the density of the Earth’s crust, and the type of geological formations present beneath the surface. In the study, we also showed the relevance of using the actual (measured) values of gradients to analyse geoid-to-quasigeoid separation. We have shown that taking the actual gradient values instead of their average (or modelled) values results in deviations in modelling the separation of both geodetic reference surfaces of up to 2 mm in the study area.Keywords: gravity, vertical gravity gradient, gravimetry, geoid-quasigeoid separation

The concept of a mobile automated diagnostic and dynamometer station for heavy trucks

Trucks are a key element that performs transport functions in many sectors of human activity. This makes ensuring their proper maintenance and performance critical. One of the solutions to this problem is the concept of a mobile automated testing and testing station. A mobile diagnostic and dynometric station based on a 6-foot container was built at the Military University of Technology in Warsaw. This bench is a self-contained unit that can be transported to various locations and carry out on-site testing and diagnostics of heavy trucks. The station is equipped with a fully open system and software that can accurately measure the performance and efficiency of the truck's engine and driveline and enforce specific automated diagnostic processes analogous to quality control tests during the production process. This information can then be used to make informed maintenance and repair decisions, helping to minimize downtime and increase overall vehicle life. The mobile diagnostic and dynamic station also provides a convenient and cost-effective alternative to traditional off-site testing methods, making it a valuable tool for transport companies and fleet managers.

Method for Evaluating the Effectiveness of Electrical Circuit Protection with Miniature Fuse-Links

Miniature fuses as an anti-damage subsystem perform the important function of protecting electronic devices and systems against permanent damage that may result in electric shocks, fire risks, etc. Their role becomes particularly important when they are installed in such special systems as electronic security systems (ESS). For this reason, there is a need for practical verification of their protective properties. The article presents the results of destructive tests of the circuit-breaking time of miniature fuse-links considered in terms of their usefulness in the ESS with the use of a passive experimental add-on, developed at the Military University of Technology in Warsaw. The characteristics of the measuring attachment circuit and the measurement methodology used were presented. Based on the obtained measurement points of the obtained time–current characteristics, an attempt was made to develop their mathematical model using numerical methods in the field of non-linear regression, using the least squares optimization method (Levenberg–Marquardt algorithm). An exemplary classification of miniature fuse-links has been proposed due to their protective properties of circuits in the context of their use in electronic security systems. The considerations were summarized with an economic analysis of the tested fuse links. The conclusions include proposals for changes to the provisions of the European standard PN-EN 50131-1:2009 “Alarm systems: Intrusion and hold-up systems Part 1: System requirements” and Polish Defence Standard NO-04-A004-8 2016 “Military facilities. Alarm systems. Part 8: Operation”.

HYPERSONIC PROPULSION SYSTEMS – A REVIEW OF DESIGN SOLUTIONS

Abstract: The development of space rocket technology in the mid-twentieth century intensified research in the field of engineering materials used both for rockets and protection of space vehicles against damage, e.g., by meteorites. This development, in turn, forced the development of laboratory propulsion systems with hypersonic velocities, enabling the study and modelling of phenomena occurring at high impact velocities. Currently, to accelerate projectiles to hypersonic velocities, launching systems are applied that use the energy of the explosion of explosives or the combustion of liquid fuels, plasma, the energy of the electromagnetic field or light gases expanding. The work presents a review of the design solutions of various accelerators that enable the projectile to reach muzzle velocities above 3000 m/s. Particular attention has been paid to two-stage gas system, which uses light gases such as hydrogen and helium. The paper also presents the history and design of the first, and so far the only, Polish two-stage light gas gun developed at the Military University of Technology, with the help of which in 1973 a projectile weighing 0.5 g was fired at a speed of 4500 m/s. The paper ends with a description of the two-stage propellant system currently under construction at the Institute of Armament Technology, Faculty of Mechatronics, Armaments and Aviation, the Military University of Technology - with the considerable help of the HSW S.A. company from Stalowa Wola.

Development of Three-Axis Fibre-Optic Seismograph for Direct and Autonomous Monitoring of Rotational Events with Perspective of Historical Review.

The paper presents historical perspective of fibre-optic seismographs designed and constructed at the Institute of Applied Physics at Military University of Technology, Poland based on the so-called minimum configuration of fibre-optic gyroscope. The briefly presented history, which originated in the 1998 by the system named GS-13P, laid solid foundations for the construction of a three-axis fibre-optic seismograph. The presented system meets all technical requirements of rotational seismology in terms of measurement parameters (measuring range from 10-8 rad/s to several rad/s and frequency from 0.01 Hz to 100 Hz) and utility features (mobility, autonomy, power independence, environmental stability). The presented device provides universal application both for research in engineering applications (high buildings, chimneys, wind towers) as well as in seismological research.

Experimental Study of Air-Assisted Rocket System Models for Launching Payloads into a Low Earth Orbit

This paper presents the results of aerodynamic testing of air-launch rocket kit models for launching payloads into a low Earth orbit. The work was performed in a low-speed wind tunnel at the Military University of Technology (MUT, Warsaw, Poland)), using symmetrical airflow. Two carrier aircraft models were tested, i.e., Su-22 and MiG-29 aircraft without launched payloads and with these payloads at a dynamic pressure of q = 500 [Pa] and the range of angles of attack at α = -2828. The values obtained related to the aerodynamic drag coefficient, aerodynamic lift coefficient, pitching moment coefficient and lift to drag ratio, and are given in tabular and graphic forms. The tests were primarily used to validate the numerical results obtained during implementation of the project “Air-assisted rocket system for launching payloads into low Earth orbit - feasibility study”.

Knowledge centre for transport accessibility and mobility of people with special needs using individual transport modes

At the Military University of Technology in Faculty of Mechanical Engineering has been estabilished a Knowledge centre for transport accessibility and mobility of people with special needs (PwSN). The main aim of the Centre’s activities is to extend issues of universal design and to develop, promote and disseminate innovative product solutions and universal service standards leading to increased mobility and improved road safety for PwSN using personal transport. An additional aim is to support teaching staff in preparation for education and in the implementation of training activities in the field of universal design, counteracting the exclusion of PwSN. The activities of the Centre involve the Faculty of Mechanical Engineering, the Institute of Psychology at Cardinal Stefan Wyszyński University and the Motor Transport Institute. The article presents in detail the intentions and expected results of the activities carried out by the Centre. It is assumed that the Centre’s activities will make it possible to develop and disseminate original solutions of systems and devices facilitating and supporting the use of individual means of transport by PwSN.

Experimental Determination of the Effect of Floats on Aerodynamic Characteristics of the “OSA” Aircraft in Asymmetric Flow

This study provides the results of experimental tests of the effect of floats on the aerodynamic characteristics of the “OSA” plane in an asymmetric flow. The tests were carried out in a low-speed wind tunnel owned by Institute of Aviation Technology, Faculty of Mechatronics, Armament and Aerospace (FMAA), Military University of Technology (MUT, Warsaw, Poland).. The model of “OSA” was tested at dynamic pressure q = 500 Pa within the range of slip angles β = -2828. The tests were carried out for the plane model in the so-called “plain” configuration, i.e. at non-deflected control surfaces and wing mechanisation elements. The model was tested in two variants – with floats and without floats. The effect of deflection of the flaps, ailerons and rudder on the aerodynamic characteristics of the test model was also examined. The obtained values of drag coefficient, lateral force coefficient and yawing moment coefficient are presented in the form of tables and graphs. The tests showed that the floats had a significant impact on the curves of the characteristics. They result in a considerable increase of the value of the drag coefficient and in a deterioration of weathercock stability.

Study on the weldability of AA2519 armor grade aluminium alloy

This paper describes series of studies concerned with welding of Sc-modified AA2519 at the Military University of Technology. The modification of AA2519 alloy contains a higher concentration of scandium and zirconium and it has been developed in The Institute of Non Ferrous Metals, Light Metals Division in Skawina. The examination involves friction stir welding (FSW) and laser beam welding (LBW) of 5 mm thick AA2519-T62 extrusion. FSW process parameters were: 600 rpm tool rotation speed, 100 mm/min welding velocity, 4.8 mm depth plunge, and MX Triflute tool type. The used LBW parameters were as follows: 3.2 kW laser power, 1.1 m/min welding velocity, 0.2 mm laser beam width, 10° laser beam inclination angle, 10 L/min shielding gas (argon) flow with the laser beam focused on the workpiece surface (f=0). In this work selected results have been presented containing some problems and features typical for investigated joints. Butt joints produced by FSW and LBW have been compared in terms of microstructure (grains), microhardness distribution, joint efficiency, localization of failure, etc. The basic features of weld zones have been discussed together with the distributions of microhardness on the joint’s cross-sections. Both welding techniques cause a reduction of microhardness in the weld zone, but the drop from the base material’s value (135-140 HV0.1) is far higher in the case of LBW (85-90 HV0.1) than FSW (120 HV0.1). The established values of joint efficiency were 80% (376 MPa) and 66% (314 MPa) for FSW and LBW, respectively. The FSW joints tend to fail in the thermo-mechanically affected zone and LBW in the fusion zone.

Performance characteristics of Hopkinson’s set-up pneumatic launcher

The paper presents a performance characteristics of a pneumatic launcher, which is an important element of the split Hopkinson bar set-up (SHPB) at the Department of Military Engineering and Infrastructure (the Military University of Technology in Warsaw) for the purpose of dynamic strength tests of construction materials. The process of experimental calibration of the launcher for selected loading bar-projectiles is shown. Two types of compression during direct impact tests were also used simultaneously to investigate the behaviour of metallic samples with the use of this launcher as well as the Hopkinson measuring bar: the first — a short cylindrical sample, including a miniature (small diameter) sample, and the second — a long cylindrical sample (Taylor test). The relationships describing the stress and strain state as a function of strain rate for the first type of the experiment and engineering empirical formulas for the second type of the research were given.

Measurement and Analysis of the Parameters of Modern Long-Range Thermal Imaging Cameras.

Today’s long-range infrared cameras (LRIRC) are used in many systems for the protection of critical infrastructure or national borders. The basic technical parameters of such systems are noise equivalent temperature difference (NETD); minimum resolvable temperature difference (MRTD); and the range of detection, recognition and identification of selected objects (DRI). This paper presents a methodology of the theoretical determination of these parameters on the basis of technical data of LRIRCs. The first part of the paper presents the methods used for the determination of the detection, recognition and identification ranges based on the well-known Johnson criteria. The theoretical backgrounds for both approaches are given, and the laboratory test stand is described together with a brief description of the methodology adopted for the measurements of the selected necessary characteristics of a tested observation system. The measurements were performed in the Accredited Testing Laboratory of the Institute of Optoelectronics of the Military University of Technology (AL IOE MUT), whose activity is based on the ISO/IEC 17025 standard. The measurement results are presented, and the calculated ranges for a selected set of IR cameras are given, obtained on the basis of the Johnson criteria. In the final part of the article, the obtained measurement results are presented together with an analysis of the measurement uncertainty for 10 LRIRCs. The obtained measurement results were compared to the technical parameters presented by the manufacturers.

Thermal Properties of Solids – Theoretical Basis, Research Methods and Selected Results of Proprietary Research

This paper refers to an inaugural lecture prepared by the author for the inauguration of the New Academic Year 2020/2021 at the Faculty of Mechatronics, Armament and Aerospace of Military University of Technology (MUT) in Warsaw (Poland) on 2 October 2020. It presents the origins of research into thermal properties of solids since the mid-1970s by the employees of the thermodynamic research unit at the Department of Aerodynamics and Thermodynamics, followed by the basic modalities of heat transfer, theoretical foundations of thermal expansion, specific heat, thermal conductivity and thermal diffusivity of solids. The measuring apparatus created as a result of proprietary research studies and purchased from market-leading manufacturers is shown with a selection of results from the research into the thermal properties of solids, which are largely the outcome of the application our own research procedures.

Directions for the development of information resource management in military libraries of higher education institutions in Poland on the example of the Library of the War Studies University and the Library of the Military University of Technology

The article addresses the directions of management development in military libraries of higher education institutions in Poland. These changes are noticeable in such areas as information technology, interpersonal communication, spatial architecture, and library budget. The article also presents two most important and largest libraries in the Polish Armed Forces, namely the Library of the War Studies University and the Library of the Military University of Technology. It provides a brief historical outline of the mother universities of these libraries and the beginnings of their activities. Then, the essential modern solutions implemented there and have directly contributed to their development, are analyzed.

MOCVD Grown HgCdTe Heterostructures for Medium Wave Infrared Detectors

This paper presents the current status of medium-wave infrared (MWIR) detectors at the Military University of Technology’s Institute of Applied Physics and VIGO System S.A. The metal–organic chemical vapor deposition (MOCVD) technique is a very convenient tool for the deposition of HgCdTe epilayers, with a wide range of compositions, used for uncooled infrared detectors. Good compositional and thickness uniformity was achieved on epilayers grown on 2-in-diameter, low-cost (100) GaAs wafers. Most growth was performed on substrates, which were misoriented from (100) by between 2° and 4° in order to minimize growth defects. The large lattice mismatch between GaAs and HgCdTe required the usage of a CdTe buffer layer. The CdTe (111) B buffer layer growth was enforced by suitable nucleation procedure, based on (100) GaAs substrate annealing in a Te-rich atmosphere prior to the buffer deposition. Secondary-ion mass spectrometry (SIMS) showed that ethyl iodide (EI) and tris(dimethylamino)arsenic (TDMAAs) were stable donor and acceptor dopants, respectively. Fully doped (111) HgCdTe heterostructures were grown in order to investigate the devices’ performance in the 3–5 µm infrared band. The uniqueness of the presented technology manifests in a lack of the necessity of time-consuming and troublesome ex situ annealing.

Concept for the Construction and Application of a Counter-UAV Defence System

This paper describes a concept for the construction and application of the Counter-UAV Defence System as developed by the Polish consortium of Zakłady Mechaniczne “Tarnów” S.A. (ZMT) and Military University of Technology (MUT). The article describes a system designed to counteract unmanned aerial vehicles, which consists of a multi-barrel machine gun and a radiolocation system. The Counter-UAV Defence System enables the combating of aerial targets, including unmanned aerial vehicles (UAVs).

Experimental Determination of the Impact of Floats on the Aerodynamic Characteristics of an OSA Model in Symmetric Flow

This paper presents the results of experimental determination of the impact of floats on the aerodynamic characteristics of an OSA model in symmetric flow. The studies have been performed in the low-speed wind tunnel at the Military University of Technology (MUT, Warsaw, Poland). The aircraft model was examined at the dynamic pressure q = 500 Pa in the following angle of attack range = -2828. The investigations have been performed for an aircraft model under plain configuration with floats and without floats. The influence of elevator and flap inclination on the aerodynamic characteristics of the model has also been analysed. The obtained values of aerodynamic drag coefficient, lift coefficient, pitching moment coefficient and lift-to-drag ratio have been presented in the form of tables and graphs. The studies performed demonstrated that the use of floats causes the increase of aerodynamic drag coefficient CD, maximum lift coefficient CLmax as well as critical angle of attack cr. The decrease of lift-to-drag ratio has also been observed. Its value in the case of the model with floats was up to 20% lower than in the model without floats. The studies also showed that the model equipped with floats had a lower longitudinal static stability margin than the model without floats.

Evolution of the MSBS Grot Assault Rifle from Version A0 to Version A2

On 15 December 2017, Fabryka Broni “Łucznik”-Radom Sp. z o.o. (FB Radom), a subsidiary of Polska Grupa Zbrojeniowa S.A., delivered the first batch of 1,000 MSBS Grot C 16 FB M1 calibre 5.56 mm standard (basic) assault rifles (version A0) to the Polish Territorial Defence Force and thus initiated the process of deployment of the assault rifle in the Polish Armed Forces. MSBS Grot was developed by Polish design and process engineers at FB Radom and the Military University of Technology (MUT, Warsaw, Poland) who by mediation of the proper Armament Acquisition and Development Department collected the improvement suggestions and operational feedback from 2.5 years of testing by operators from the armed forces. The suggestions and feedback were thoroughly analysed and discussed during periodic meetings attended by the representatives of the Territorial Defence Force (TDF) Command, the Special Forces Component Command, the 3rd Regional Military Representation (RMR), MUT, and FB Radom. Based on the conclusions from the testing period and the results of theoretical and instrumental testing of the solutions proposed for implementation, the MSBS Grot assault rifles show systematic improvements up to the current version, A2. This paper presents the design of the MSBS Grot Version A0 assault rifle and the construction and processing modifications for version A1 and version A2. During the optimisation effort backed by theoretical and instrumental testing, there was special focus on the assurance of high operating safety and reliability, plus the required ergonomics of the assault rifle under various operating conditions. The paper also presents the avenues for further potential improvements of MSBS Grot.