Conceptual design and operation testing of military movable noiseless power supplier (MNPS)

This study verifies the concept and test of the MNPS owing to the increase in advanced weapon systems used in the Korean defense field. MNPS used solar power to eliminate noise, a risk factor of the existing power supply systems, and it was designed in a size that can be mounted on a small tactical vehicle in various battlefield situations. When sunlight is used as a power supplier, in case there is no light, its use is limited; therefore, it can be used after charging through an energy storage device. In addition, it was designed considering scalability to increase the amount of electricity generated through the solar panel or increase the storage capacity. Finally, the power characteristics were analyzed through a test to determine if the output was constant, and through this, it was possible to confirm its feasibility of use for military purposes.

Effect of Ruthenium Oxide Content on the Electrochemical Characteristics of a Supercapacitor With a Carbon Black Electrode Formed by Electrophoretic Deposition

Controlling the ratio of capacitance and power of supercapacitors by changing the composition of the electrodes will allow to create optimal power systems for specific applications. For the formation of such electrodes, a method is required that combines the possibilities of creating a multicomponent composite with a high degree of uniformity of composition and morphology over the layer thickness. An example of such a method can be the eco-friendly method of electrophoretic deposition used in this work, which makes it possible to locally deposit a composite material from multicomponent suspensions at room temperature. We present an approach related to electrophoretic deposition from a suspension of composite material SuperC-RuO 2 , in which the ratio of the components can be changed to vary the proportion of electrochemical and electrical double layer storage. Nanocarbon, which has a large surface area, and ruthenium oxide with a significant electrochemical capacity, in combination, will allow combining high power and capacity in one device, and their ratio will determine the proportion of electrochemical and electrical double layer storage. In this work, approaches are investigated and recommendations are given for increasing the stability of suspensions, the effect of the composition of the suspension on the composition of composite electrodes and their capacitive and power characteristics is determined.

METHOD FOR CALCULATING CUTTING FORCES BY MODELING CAD WITH A SYSTEM OF GEOMETRIC CUTTING PARAMETERS WITH RADIAL MILLS

The accuracy of processing surfaces of a complex profile largely depends on the selected processing strategy, which will allow creating the same, within certain limits, power characteristics of the shaping process at the intervals of the programmed tool path. In this case, it becomes possible to include tuning modules in programs for CNC machines that form vector values of corrections in certain areas, as reactors for elastic deformations of the cutting process. Therefore, it is especially important to know the modulus and direction of the resulting cutting force vector, which does not necessarily coincide with the feed direction. The purpose of this work is to build a method for calculating cutting forces by modeling the geometric parameters of a cut with a CAD system, a cutter with a nonlinear generatrix. Solid modeling of the process is based on the Boolean operations of "intersection" and "subtraction" of 3D objects: the teeth of a radius cutter with a helical cutting edge and a workpiece "moving" at a feed rate. The tool for the implementation of this method is a software module created on the basis of API functions, the input data for which are: a 3D tool and a workpiece, the equation of the trajectory of its movement and the parameters of the infeed movement. Targeting API properties, the application makes it possible to simulate various trajectories, helical or trochoidal, when machining complex surfaces. In the future, it is possible to take into account the plastic deformation processes in the chip formation zone in the model by connecting external modules. In the course of the conducted research on milling with radial end mills with a helical cutting edge, when two or more teeth are within the arc of contact, it was determined by 3D modeling how much thickness and width the layer cuts off each of the teeth during the feed per revolution. Consequently, in the process of shaping, normal and tangential cutting forces, which are different in direction and modulus, are present as a function of the angle of rotation of the cutter. Therefore, the concept of "circumferential force on the cutter", accepted in the theory of cutting, as a certain constant component of the process, can introduce an error when considering the causes of the excitation mechanism of vibrations of different nature that arise in the processing zone.

Justification of the Application of Resource-Saving Technology for the Restoration of Metal-Intensive Rear Semi-Axles of Trucks Using Hot Plastic Deformation

The article is devoted to the substantiation of technological foundations for the restoration of extremely worn-out, metal-consuming, and resource-consuming parts, in a method consisting of applying a compensating metal wear with subsequent plastic deformation. Currently, there are no technologies for their restoration in a repair facility that guarantee the resilience of the factory product. The proposed technological process of repair consists of butt welding onto the end of the spline semi-axle shank, compensating for the wear of the metal, the volume of which takes into account the losses resulting from the wear of the slots, as well as allowances for their machining. In the example of forging the axle shaft of a truck’s driving axle, the regularities of the plastic flow of metal during part deformation in the stamp are revealed. In the process of hot volumetric upsetting of long cylindrical parts with a variable diameter, it is important to know the possible directions of metal movements, as well as the energy-power characteristics of the process at various stages of forging. The evaluation criteria of the level of perfection of the technology were indicators of resource conservation and efficiency of the recovery route. The technological direction of the conducted research was analyzed, step by step, from the standpoint of saving repair materials and energy resources. The results of theoretical studies are crucial in the design of die tooling, for the manufacture of blanks, when restoring the rear axle shafts of trucks with pressure. Production tests carried out on the models, obtained as a result of mathematical processing of experimental data, confirmed the reliability of the experimental information. The introduction of the proposed set of repair equipment for the restoration of semi-axles will allow the formation of additional production in the region for the recycling of worn-out metal-intensive steel parts of agricultural machinery.

Fatigue mitigation of wind turbine system using multiple point model predictive control

<span lang="EN-US">A multi-point model predictive control (MPMPC) is widely used for many applications, including wind energy system (WES), notably enhanced power characteristics and oscillation regulation. In this work, MPMPC is adapted to condense the fatigue load of the WES and improve the lifetime of the turbine assembly. The lifetime examination is carried out by considering the three chief parameters: basic lifetime until failure, short-time damage equivalent loads (DELs), and lifetime DELs. The simulation study is performed for two cases: blade root bending moments and tower top bending. Further, fatigue load examination is demonstrated to analyze the effectiveness of the proposed controller. The observed results show that the lifetime analysis of the wind turbine system displayed more excellent characteristics, i.e., 49.50% greater than MPC. Also, the fatigue load mitigation showed greater magnitude due to the control action of the proposed controller, about 37.38% grander than MPC. Therefore, the attained outcomes exhibit outstanding performance compared with conventional controllers.</span>

Analysis of the Operation of an Arched Elastomeric Shock Absorber Under Two-Axial Loading

Elastomeric shock absorbers are used in various technical fields to protect equipment from impacts. Elastomers made in an arched shape have complex nonlinear force characteristics due to large deformations, loss of stability of working elements and closing of surfaces. In this regard, obtaining the power characteristics of arched elastomeric shock absorbers is a complex computational problem. It is noteworthy that, in the literature, these characteristics are given only for the case of normal compression. However, when assessing the possibility of using a shock-absorbing system based on arched elastomeric shock absorbers, it is necessary to take into account their lateral force. The study proposes to solve the problem of determining the elastic force characteristics of a shock absorber while operating in the normal and lateral directions in the system of finite element analysis in a flat formulation. Analytical expressions are obtained for the normal and transverse static reactions of the shock absorber under simultaneous loading in the normal and transverse directions. Analytic expressions can be used to simulate complex shock-absorbing systems with a large number of such shock absorbers.

Development of a methodology for calculating the working process of a small-size two-stroke internal combustion engine

On the basis of the available theoretical calculations, methods for calculating the working process and power characteristics of internal combustion engines and the experimental studies carried out, a method for calculating the working process for small-sized two-stroke internal combustion engines was developed and tested. In the course of this work, the following results were obtained: the parameters of the working process and power characteristics of a small two-stroke internal combustion engine; the parameters obtained by calculation during the study of the Evolution 20GX2 engine were compared with the results of an experimental study. According to the results of the comparison, deviations in the values of the parameters of the engine under study from the results of the experimental study at the maximum power and maximum speed modes were identified.