The article presents the significance of applying thermomechanical techniques in the investigation of solid propellants used in rocket motors. Attention is given to the use of Dynamic Mechanical Analysis (DMA) and Thermomechanical Analysis (TMA). These methods enable the characterization of viscoelastic properties as well as the assessment of the stability of solid rocket propellants. Furthermore, the theoretical foundations of both methods are discussed, along with their scope of application and significance in analyzing material structural behavior. The interpretation of DMA results is presented with regard to the determination of the glass transition temperature. In the case of TMA, the importance of evaluating thermal expansion and structural deformation of solid propellants under temperature influence is described. Received thermomechanical test results may contribute to improving the safety of operation of solid rocket propellants.
As part of this project, comprehensive flow studies were conducted for various proposed design variants, taking into account the defined parameters accompanying the firing phenomenon. The research was aimed at collecting data on the behavior of flows inside suppressor cartridges under conditions associated with the firing process. Parameters such as pressure, temperature, velocity and properties of individual geometries were systematically recorded and analyzed. The results obtained formed the basis for the analysis, allowing the comparison of different design variants and evaluation of their effectiveness. In addition, a comparison was made between the designed inserts dedicated to incremental manufacturing and the comparative inserts made by the existing technology of cavity machining. Part IV contains the numerical simulations of complete damping insert version I using SolidWorks Flow Simulation software.
In the frame of this project the comprehensive flow studies were carried out for different design configurations taking into account the defined parameters accompanying the firing phenomenon. Tests were aimed at collecting data on the behavior of flows inside suppressor cartridges under conditions associated with the firing process. Parameters such as pressure, temperature, velocity and properties of individual geometries were systematically recorded and analyzed. The obtained results formed the basis for the analysis, allowing the comparison of different design variants and evaluation of their effectiveness. In addition, a comparison was made between the designed inserts dedicated to incremental manufacturing and a comparative insert which can be produced by the existing technology of cavity machining. Part III contains the results of numerical analyses of the designed expansion chambers using SolidWorks Flow Simulation software.
Given the invaluable importance of electronic warfare (EW) to national security, consistently demonstrated during the war in Ukraine, this article attempts to introduce the reader to the topic. The first section of the article presents the origins of EW-related issues and a general classification of electronic warfare (EW) jamming methods. The next section provides a detailed discussion of current jamming methods currently used in radars. The final section presents various variants/techniques of active jamming of pulsed LFM radars that have been developed in recent years. The article ends with a summary in the form of conclusions.
Two energetic ingredients, 2,4-dinitroanisole (DNAN) and the high-density heterocyclic explosive 4,10-dinitro-2,6,8,12-tetraoxa-4,10-diazatetracyclo-[5.5.0.05,903,11]dodecane (TEX), were investigated as components of fusible insensitive explosive formulations. DNAN, a low-melting aromatic nitrocompound, offers practical advantages for melt-casting relative to conventional melt-castable explosives, while exhibiting different mechanical sensitivities and detonation performance compared with benchmark materials. TEX is a promising high-performance secondary explosive that can improve the overall performance of insensitive compositions. A series of cast formulations based on DNAN/TEX with and without wax were prepared to evaluate the influence of inert additive on thermal stability and decomposition behavior. Thermal analysis using differential scanning calorimetry under varying heating conditions was employed to characterize decomposition events, and kinetic parameters were estimated using an isoconversional approach implemented in commercial software. The presence of wax additives modified the decomposition kinetics and thermal response of the formulations. Results are discussed in terms of implications for the safe production, storage, and handling of melt-cast insensitive explosive compositions.
