Optimization of the rocket’s nose and nozzle design parameters in respect to its aerodynamic characteristics

The airflow around rockets with various nose cone and nozzle cone geometric parameters is investigated in this paper. The mathematical background and the computational model of airflow around the rocket are designed for that purpose. ANSYS CFX computer modeling software is used to compute the airflow velocities, pressure, airflow turbulence kinetic energy, drag force and drag coefficient dependencies on rocket flight velocity. Optimization of the rocket’s nose cone and nozzle cone geometry in respect to qualitative and quantitative parameters of rocket’s aerodynamic characteristics is performed

Development of mortar simulator with shell-in-shell system – problem of internal ballistics

The shell-in-shell system used in the mortar simulator raises a number of non-standard technical and computational problems starting from the requirement to distribute the propelling blast energy between the warhead and the ballistic barrel, finishing with the requirement that the length of warhead’s flight path must be scaled to combat shell firing tables. The design problem of the simulator is split into two parts – the problem of external ballistics where the initial velocities of the warhead must be determined, and the problem of internal ballistics – where the design of the cartridge and the ballistic barrel must be performed. Initial velocities of the warhead determined in the problem of external ballistics form the set of initial data for the problem of internal ballistics of mortar simulator with shell-in-shell system. The ballistic barrel (reusable component of the mimicking shell) must be ejected from the mortar tube and its flight path must be only few meters. Moreover, the propelling charge can be located only in the warhead and the blast energy must be distributed between the warhead and the ballistic barrel. That turns the problem of internal ballistics into a complex nonlinear dynamical problem. Its solution involves building of the numerical model, optimisation of system parameters and experimental investigations. Presented mortar simulator proved its effectiveness in combat training exercises and is fully adopted in Lithuanian Army training facilitie

Various Types of Piezomechanics Systems: Their Regimen and Experimental Analysis

The layered piezoactuators used in mechanisms requiring high precizion displacements have indicated that accuracy depends on design and technological factors. One of essential requirements for compound piezoactuators is their capability of transferring unipolar or bipolar force. In the first version, the piezoactuators acting in one direction is made of separate piezoelements and adapted binding materials. They operate under positive deformation (elongation due to neutral position) when the applied voltage is positive to polarity. The layered piezoactuators returns to its initial position under negative deformation (contraction) when the polarity voltage is applied opposite. The piezoactuators deformation in this direction only due to small forces of binding materials. When the piezoceramic is deformed by an external electric field, the input electrical energy is larger than the output mechanical energy. The ineffective electrical energy is stored as electrostatic energy in the piezostack and reverts to the power supply in the final process of an operating cycle. The efficiency is determined only by the loss such as hysteresis in the strain curve. The electromechanical feedback affects the correction of the hysteresis. It is evident that by applying the electromechanical feedback the hysteresis can be corrected up to 0.2% from the maximum displacement

The dynamics of the one-way pneumatic drive for training weapons

Riflemen’s trainers are efficiently applied for the training of the armed forces, police and shooting athletes. However, the training quality directly depends on the perfection of trainers as well as their functional facilities. Trainers should qualitatively develop the skills of correct levelling of a gun to target, represent probable combat situations and reproduce the process of single and shot series. The work presents the theoretical and experimental investigation of the pneumatic drive for recoil imitation of the weapo

Design and research of a laser trainer with all the functions of the G – 36

Riflemen trainers are effectively applied for the training of armed forces, police and shooting athletes. However, the training quality directly depends on the perfection of trainers as well as their functional features. Trainers should qualitatively develop the skills of correct leveling of the G-36 to the target, represent probable combat situations and reproduce the process of single shots and shot series. This research work presents the theoretical and experimental investigation of the pneumatic drive for recoil imitation of the automatic gun G-36 and its employment in the laser riflemen trainers

Optimization of the rocket’s nose and nozzle design parameters in respect to its aerodynamic characteristics

The airflow around rockets with various nose cone and nozzle cone geometric parameters is investigated in this paper. The mathematical background and the computational model of airflow around the rocket are designed for that purpose. ANSYS CFX computer modeling software is used to compute the airflow velocities, pressure, airflow turbulence kinetic energy, drag force and drag coefficient dependencies on rocket flight velocity. Optimization of the rocket’s nose cone and nozzle cone geometry in respect to qualitative and quantitative parameters of rocket’s aerodynamic characteristics is performed

Development of mortar simulator with shell-in-shell system – problem of internal ballistics

The shell-in-shell system used in the mortar simulator raises a number of non-standard technical and computational problems starting from the requirement to distribute the propelling blast energy between the warhead and the ballistic barrel, finishing with the requirement that the length of warhead’s flight path must be scaled to combat shell firing tables. The design problem of the simulator is split into two parts – the problem of external ballistics where the initial velocities of the warhead must be determined, and the problem of internal ballistics – where the design of the cartridge and the ballistic barrel must be performed. Initial velocities of the warhead determined in the problem of external ballistics form the set of initial data for the problem of internal ballistics of mortar simulator with shell-in-shell system. The ballistic barrel (reusable component of the mimicking shell) must be ejected from the mortar tube and its flight path must be only few meters. Moreover, the propelling charge can be located only in the warhead and the blast energy must be distributed between the warhead and the ballistic barrel. That turns the problem of internal ballistics into a complex nonlinear dynamical problem. Its solution involves building of the numerical model, optimisation of system parameters and experimental investigations. Presented mortar simulator proved its effectiveness in combat training exercises and is fully adopted in Lithuanian Army training facilitie

Defence and Security Public Procurement: Analysis of Managerial and Legal Issues

Публічні закупівлі, як система процедур закупівлі товарів та послуг, є досить складними. Особливо маючи на увазі міжнародне правове регулювання та високі вимоги до забезпечення таких принципів, як прозорість, чесна конкуренція, недискримінація, взаємне визнання, пропорційність. Таким чином, в таких спеціальних сферах, як оборона та національна безпека, не завжди занадто суворо можна дотримуватися зазначених правил. Інституції в державі, які стикаються з загрозами, повинні бути гнучкими – це дозволить збалансувати терміновість та конкурентоспроможність процедур закупівлі. Тим не менш такі ситуації вимагають чіткої системи управління та законності регулювання його підтримки. У цій статті автори представляють попередній аналіз управління публічними закупівлями для захисту безпеки через теорію циклу управління надзвичайними ситуаціями та зосереджуються головним чином на фазі реагування на певних деструктивних діях. Зазначені питання постійно вивчаються, і ця стаття є основним кроком до глибокого аналізу про безперервність державних дій у ситуаціях реальних загроз та напруженості, які сьогодні стоять перед Європою.Public procurement, as a system for purchasing goods and services, is rather complicated particularly with regard to international legal regulation and high requirements for the provision of such principles as transparency, fair competition, non-discrimination, mutual recognition, proportionality. Thus, in such special areas as defense and national security, it is not always too strict to adhere to these rules. Institutions in the state facing threats must be flexible – this will balance the urgency and competitiveness of procurement procedures. Nevertheless, such situations require a clear system of governance and the legality of regulating its support. In this article, the authors present a preliminary analysis of the management of public procurement to protect security through the theory of emergency management cycle and focus mainly on the phase of responding to certain destructive actions. These issues are constantly being studied, and this article is a major step towards a thorough analysis of the continuity of government actions in the real-world situations of tension and threats that Europe faces today.Публичные закупки, как система процедур закупки товаров и услуг, являются достаточно сложными, особенно принимая во внимание международное правовое регулирование и высокие требования к обеспечению таких принципов, как прозрачность, честная конкуренция, недискриминация, взаимное признание, пропорциональность. Таким образом, в таких специальных областях, как оборона и национальная безопасность, не всегда слишком строго можно придерживаться указанных правил. Институты в государстве, которые сталкиваются с угрозами, должны быть гибкими – это позволит сбалансировать срочность и конкурентоспособность процедур закупки. Тем не менее, такие ситуации требуют четкой системы управления и законности регулирования его поддержки. В этой статье авторы представляют предварительный анализ управления публичными закупками для защиты безопасности через теорию цикла управления чрезвычайными ситуациями и сосредотачиваются главным образом на фазе реагирования на определенных деструктивных действиях. Указанные вопросы постоянно изучаются, и эта статья является основным шагом к глубокому анализу о непрерывности государственных действий в ситуациях реальных угроз и напряженности, которые сегодня стоят перед Европой

Defence and Security Public Procurement: Analysis of Managerial and Legal Issues

Публічні закупівлі, як система процедур закупівлі товарів та послуг, є досить складними. Особливо маючи на увазі міжнародне правове регулювання та високі вимоги до забезпечення таких принципів, як прозорість, чесна конкуренція, недискримінація, взаємне визнання, пропорційність. Таким чином, в таких спеціальних сферах, як оборона та національна безпека, не завжди занадто суворо можна дотримуватися зазначених правил. Інституції в державі, які стикаються з загрозами, повинні бути гнучкими – це дозволить збалансувати терміновість та конкурентоспроможність процедур закупівлі. Тим не менш такі ситуації вимагають чіткої системи управління та законності регулювання його підтримки. У цій статті автори представляють попередній аналіз управління публічними закупівлями для захисту безпеки через теорію циклу управління надзвичайними ситуаціями та зосереджуються головним чином на фазі реагування на певних деструктивних діях. Зазначені питання постійно вивчаються, і ця стаття є основним кроком до глибокого аналізу про безперервність державних дій у ситуаціях реальних загроз та напруженості, які сьогодні стоять перед Європою.Public procurement, as a system for purchasing goods and services, is rather complicated particularly with regard to international legal regulation and high requirements for the provision of such principles as transparency, fair competition, non-discrimination, mutual recognition, proportionality. Thus, in such special areas as defense and national security, it is not always too strict to adhere to these rules. Institutions in the state facing threats must be flexible – this will balance the urgency and competitiveness of procurement procedures. Nevertheless, such situations require a clear system of governance and the legality of regulating its support. In this article, the authors present a preliminary analysis of the management of public procurement to protect security through the theory of emergency management cycle and focus mainly on the phase of responding to certain destructive actions. These issues are constantly being studied, and this article is a major step towards a thorough analysis of the continuity of government actions in the real-world situations of tension and threats that Europe faces today.Публичные закупки, как система процедур закупки товаров и услуг, являются достаточно сложными, особенно принимая во внимание международное правовое регулирование и высокие требования к обеспечению таких принципов, как прозрачность, честная конкуренция, недискриминация, взаимное признание, пропорциональность. Таким образом, в таких специальных областях, как оборона и национальная безопасность, не всегда слишком строго можно придерживаться указанных правил. Институты в государстве, которые сталкиваются с угрозами, должны быть гибкими – это позволит сбалансировать срочность и конкурентоспособность процедур закупки. Тем не менее, такие ситуации требуют четкой системы управления и законности регулирования его поддержки. В этой статье авторы представляют предварительный анализ управления публичными закупками для защиты безопасности через теорию цикла управления чрезвычайными ситуациями и сосредотачиваются главным образом на фазе реагирования на определенных деструктивных действиях. Указанные вопросы постоянно изучаются, и эта статья является основным шагом к глубокому анализу о непрерывности государственных действий в ситуациях реальных угроз и напряженности, которые сегодня стоят перед Европой

Development of mortar simulator with shell-in-shell system – problem of internal ballistics

The shell-in-shell system used in the mortar simulator raises a number of non-standard technical and computational problems starting from the requirement to distribute the propelling blast energy between the warhead and the ballistic barrel, finishing with the requirement that the length of warhead’s flight path must be scaled to combat shell firing tables. The design problem of the simulator is split into two parts – the problem of external ballistics where the initial velocities of the warhead must be determined, and the problem of internal ballistics – where the design of the cartridge and the ballistic barrel must be performed. Initial velocities of the warhead determined in the problem of external ballistics form the set of initial data for the problem of internal ballistics of mortar simulator with shell-in-shell system. The ballistic barrel (reusable component of the mimicking shell) must be ejected from the mortar tube and its flight path must be only few meters. Moreover, the propelling charge can be located only in the warhead and the blast energy must be distributed between the warhead and the ballistic barrel. That turns the problem of internal ballistics into a complex nonlinear dynamical problem. Its solution involves building of the numerical model, optimisation of system parameters and experimental investigations. Presented mortar simulator proved its effectiveness in combat training exercises and is fully adopted in Lithuanian Army training facilitie