T. N. Dung, V. Horak, The Nguyen Luc, Van Nguyen Dung, Duc Do Linh
The article is directly related to the authors’ previous study of the remotely operated underwater vehicle’s (ROV) motion, where the mathematical model of the ROV motion is derived for laminar flow of water. This solution of the ROV motion has been improved by using the three-dimensional computational fluid dynamics (CFD) simulation that allows simulating the turbulent flow, which is mainly generated by propellers. Both methods were coupled to obtain more accurate values of hydrodynamic damping coefficients for the improved determination of the ROV motion velocity. Results of the solution are discussed and some of them are compared with the experiment.
{"title":"A Motion Model of a Remotely Operated Underwater Vehicle: CFD Simulation","authors":"T. N. Dung, V. Horak, The Nguyen Luc, Van Nguyen Dung, Duc Do Linh","doi":"10.3849/aimt.1491","DOIUrl":"https://doi.org/10.3849/aimt.1491","url":null,"abstract":"The article is directly related to the authors’ previous study of the remotely operated underwater vehicle’s (ROV) motion, where the mathematical model of the ROV motion is derived for laminar flow of water. This solution of the ROV motion has been improved by using the three-dimensional computational fluid dynamics (CFD) simulation that allows simulating the turbulent flow, which is mainly generated by propellers. Both methods were coupled to obtain more accurate values of hydrodynamic damping coefficients for the improved determination of the ROV motion velocity. Results of the solution are discussed and some of them are compared with the experiment.","PeriodicalId":39125,"journal":{"name":"Advances in Military Technology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45349845","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The radar matched filter is implemented in fractional Fourier domain (FrFD) and the required processing steps to perform the radar matched filter in FrFD are demonstrated. The complexity of the FrFD matched filter over the normal frequency transform matched filter is also investigated. The performance enhancements for using the matched filter in the FrFD are presented and the enhancement in the signal to noise ratio (SNR) output at different target SNRs are also described.
{"title":"Matched Filter Implementation, Complexity, and Gain in Fractional Fourier Domain","authors":"S. Elgamel","doi":"10.3849/aimt.01513","DOIUrl":"https://doi.org/10.3849/aimt.01513","url":null,"abstract":"The radar matched filter is implemented in fractional Fourier domain (FrFD) and the required processing steps to perform the radar matched filter in FrFD are demonstrated. The complexity of the FrFD matched filter over the normal frequency transform matched filter is also investigated. The performance enhancements for using the matched filter in the FrFD are presented and the enhancement in the signal to noise ratio (SNR) output at different target SNRs are also described.","PeriodicalId":39125,"journal":{"name":"Advances in Military Technology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45578674","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dynamic engraving process of 23 mm projectile was studied using numerical simulation. A finite element model of projectile and barrel during the engraving process was constructed, and the deformation process of the driving band, the displacement parameters of the projectile, the force interaction between the projectile and the barrel were determined. To evaluate the simulation model, a semi-static experiment was carried out on an MTS-810 universal testing machine with a cross-head speed of 20 mm min−1. The simulation results show that the mechanism of the 23 mm projectile rotating band engraving process is the plastic deformation process of the rotating band material, engraving time is 1.12 m s, and the projectile velocity after engraving is 105 m s−1. The simulation results reflect the actual rotating band engraving process, which is very distinct from the assumptions used in the classical ballistic model. This work provides an approach to investigating the interior ballistic processes considering the dynamic engraving of rotating bands.
采用数值模拟方法研究了23mm弹丸的动态雕刻过程。建立了刻蚀过程中弹丸与枪管的有限元模型，确定了驱动带的变形过程、弹丸的位移参数、弹丸与枪管之间的力相互作用。为了对仿真模型进行验证，在MTS-810型万能试验机上进行了半静态实验，实验速度为20 mm min−1。仿真结果表明，23 mm弹丸旋转带雕刻过程的机理是旋转带材料的塑性变形过程，雕刻时间为1.12 m s，雕刻后弹丸速度为105 m s−1。仿真结果反映了实际的旋带雕刻过程，与经典弹道模型的假设有很大的不同。这项工作为研究考虑旋转带动态雕刻的内弹道过程提供了一种方法。
{"title":"Modeling and Simulation on the Rotating Band Engraving Process of 23 mm Projectile","authors":"V. M. Do, X. S. Bui, V. Nguyen","doi":"10.3849/aimt.1521","DOIUrl":"https://doi.org/10.3849/aimt.1521","url":null,"abstract":"Dynamic engraving process of 23 mm projectile was studied using numerical simulation. A finite element model of projectile and barrel during the engraving process was constructed, and the deformation process of the driving band, the displacement parameters of the projectile, the force interaction between the projectile and the barrel were determined. To evaluate the simulation model, a semi-static experiment was carried out on an MTS-810 universal testing machine with a cross-head speed of 20 mm min−1. The simulation results show that the mechanism of the 23 mm projectile rotating band engraving process is the plastic deformation process of the rotating band material, engraving time is 1.12 m s, and the projectile velocity after engraving is 105 m s−1. The simulation results reflect the actual rotating band engraving process, which is very distinct from the assumptions used in the classical ballistic model. This work provides an approach to investigating the interior ballistic processes considering the dynamic engraving of rotating bands.","PeriodicalId":39125,"journal":{"name":"Advances in Military Technology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45683228","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dynamic engraving process of 23 mm projectile was studied using numerical simulation. A finite element model of projectile and barrel during the engraving process was constructed, and the deformation process of the driving band, the displacement parameters of the projectile, the force interaction between the projectile and the barrel were determined. To evaluate the simulation model, a semi-static experiment was carried out on an MTS-810 universal testing machine with a cross-head speed of 20 mm min−1. The simulation results show that the mechanism of the 23 mm projectile rotating band engraving process is the plastic deformation process of the rotating band material, engraving time is 1.12 m s, and the projectile velocity after engraving is 105 m s−1. The simulation results reflect the actual rotating band engraving process, which is very distinct from the assumptions used in the classical ballistic model. This work provides an approach to investigating the interior ballistic processes considering the dynamic engraving of rotating bands.
采用数值模拟方法研究了23mm弹丸的动态雕刻过程。建立了弹丸和枪管在雕刻过程中的有限元模型，确定了驱动带的变形过程、弹丸的位移参数、弹丸与枪管之间的力相互作用。为了评估模拟模型，在十字头速度为20 mm min−1的MTS-810通用试验机上进行了半静态实验。仿真结果表明，23mm弹丸旋转带雕刻过程的机理是旋转带材料的塑性变形过程，雕刻时间为1.12m/s，雕刻后的弹丸速度为105m/s−1。模拟结果反映了实际的旋转带雕刻过程，这与经典弹道模型中使用的假设非常不同。这项工作为研究考虑旋转带动态雕刻的内弹道过程提供了一种方法。
{"title":"Modeling and Simulation on the Rotating Band Engraving Process of 23 mm Projectile","authors":"Minh Do V., S. X, Huong Nguyen V.","doi":"10.3849/aimt.01521","DOIUrl":"https://doi.org/10.3849/aimt.01521","url":null,"abstract":"Dynamic engraving process of 23 mm projectile was studied using numerical simulation. A finite element model of projectile and barrel during the engraving process was constructed, and the deformation process of the driving band, the displacement parameters of the projectile, the force interaction between the projectile and the barrel were determined. To evaluate the simulation model, a semi-static experiment was carried out on an MTS-810 universal testing machine with a cross-head speed of 20 mm min−1. The simulation results show that the mechanism of the 23 mm projectile rotating band engraving process is the plastic deformation process of the rotating band material, engraving time is 1.12 m s, and the projectile velocity after engraving is 105 m s−1. The simulation results reflect the actual rotating band engraving process, which is very distinct from the assumptions used in the classical ballistic model. This work provides an approach to investigating the interior ballistic processes considering the dynamic engraving of rotating bands.","PeriodicalId":39125,"journal":{"name":"Advances in Military Technology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48076864","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This research resulted from military interest in finding methods to provide distributed electricity generation in order to support comprehensive state defence measures. The aim of the study was to investigate the effect of a heated air-fuel mixture on the combustion process of a spark ignition (SI) engine, and to highlight the maximum temperatures to be applied to air-fuel mixtures with different fuel fractions in order to avoid any detonation of the fuel mixture in the engine. Tests were carried out with a petrol engine generator (GENSET) so that an investigation could be conducted into the effect of the air-fuel mixture on the engine’s combustion. It turned out that heating the air-fuel mixture permits the use of heavier fraction fuels than engine petrol in SI engines does, including diesel fuel and biodiesel fuel, and also that the use of heavy fraction fuels in SI engines is effective mainly under low and middle loads.
{"title":"Air-Fuel Mixture Temperatures with Light and Heavy Fuels for Effective Spark Ignition Engine Work","authors":"V. Raide, R. Ilves, J. Olt","doi":"10.3849/aimt.1501","DOIUrl":"https://doi.org/10.3849/aimt.1501","url":null,"abstract":"This research resulted from military interest in finding methods to provide distributed electricity generation in order to support comprehensive state defence measures. The aim of the study was to investigate the effect of a heated air-fuel mixture on the combustion process of a spark ignition (SI) engine, and to highlight the maximum temperatures to be applied to air-fuel mixtures with different fuel fractions in order to avoid any detonation of the fuel mixture in the engine. Tests were carried out with a petrol engine generator (GENSET) so that an investigation could be conducted into the effect of the air-fuel mixture on the engine’s combustion. It turned out that heating the air-fuel mixture permits the use of heavier fraction fuels than engine petrol in SI engines does, including diesel fuel and biodiesel fuel, and also that the use of heavy fraction fuels in SI engines is effective mainly under low and middle loads.","PeriodicalId":39125,"journal":{"name":"Advances in Military Technology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49249525","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
V. Lukyanchuk, B. Lanetskii, I.V. Koval, P. Open’ko, V.V. Tуurin, V. Khoma
During the long-term operation, anti-aircraft missile weapons are characterized by the technical condition and level of reliability change influeincing the efficiency on the intended use. The article presents a model of surface-to-air missile system (SAMS) reliability during long-term operation, which contains a set of models, namely: a model of operation of ground combat assets (GCA) of SAMS according to the typical cyclogram of intended use (TCIU); a reliability dynamics model of SAMS GCA in the established system of maintenance and repair (SMR) and a reliability dynamics model of surface-to-air missiles (SAM) during extended usage. It is expedient to use the developed model at substantiation of requirements to the indicators of SAMS and SAM reliability for their development or modernization; when developing SAMS repair plans in terms of determining the time of SAMS GCA and (or) SAM repairing time and when developing methods for assessing the effectiveness of SAMS taking into account the duration of SAMS GCA and SAMS usage.
{"title":"Model of the Surface-to-Air Missile System Reliability during Long-Term Operation","authors":"V. Lukyanchuk, B. Lanetskii, I.V. Koval, P. Open’ko, V.V. Tуurin, V. Khoma","doi":"10.3849/aimt.1506","DOIUrl":"https://doi.org/10.3849/aimt.1506","url":null,"abstract":"During the long-term operation, anti-aircraft missile weapons are characterized by the technical condition and level of reliability change influeincing the efficiency on the intended use. The article presents a model of surface-to-air missile system (SAMS) reliability during long-term operation, which contains a set of models, namely: a model of operation of ground combat assets (GCA) of SAMS according to the typical cyclogram of intended use (TCIU); a reliability dynamics model of SAMS GCA in the established system of maintenance and repair (SMR) and a reliability dynamics model of surface-to-air missiles (SAM) during extended usage. It is expedient to use the developed model at substantiation of requirements to the indicators of SAMS and SAM reliability for their development or modernization; when developing SAMS repair plans in terms of determining the time of SAMS GCA and (or) SAM repairing time and when developing methods for assessing the effectiveness of SAMS taking into account the duration of SAMS GCA and SAMS usage.","PeriodicalId":39125,"journal":{"name":"Advances in Military Technology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49223753","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
I. S. Kravchuk, D. Bashynskyi, V. V. Taranenko, M. Zirka
The possibility of a significant flight range extension of a guided aerial bomb during climb bombing due to the jet thrust created by a solid-propellant rocket engine was considered. By means of simulation, a comparative analysis of the range of a guided aerial bomb equipped (not equipped) with a solid-propellant rocket engine under typical flight conditions of the carrier aircraft during level flight and climb bombing was performed. It was demonstrated that the use of a solid-propellant rocket engine, whose mass is 20 % of the guided aerial bomb’s mass, allows to increase the horizontal range of its flight at least twice.
{"title":"Flight Range Extension of a Guided Aerial Bomb with a Rocket Engine during Climb Bombing","authors":"I. S. Kravchuk, D. Bashynskyi, V. V. Taranenko, M. Zirka","doi":"10.3849/aimt.1462","DOIUrl":"https://doi.org/10.3849/aimt.1462","url":null,"abstract":"The possibility of a significant flight range extension of a guided aerial bomb during climb bombing due to the jet thrust created by a solid-propellant rocket engine was considered. By means of simulation, a comparative analysis of the range of a guided aerial bomb equipped (not equipped) with a solid-propellant rocket engine under typical flight conditions of the carrier aircraft during level flight and climb bombing was performed. It was demonstrated that the use of a solid-propellant rocket engine, whose mass is 20 % of the guided aerial bomb’s mass, allows to increase the horizontal range of its flight at least twice.","PeriodicalId":39125,"journal":{"name":"Advances in Military Technology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49229291","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This article presents a method to establish the dynamic model of the Shooter-weapon system when firing based on Lagrange’s theorem and the theory of multibody system dynamics, in which the influence of the human body was taken into account. In the dynamic model, the influence of the gunner is solved by using elastic-damping links in the x, y and z axes. The dynamic model is created for a portable gas-operated submachine gun and contains three solids with seven degrees of freedom. The 7.62 mm AKM submachine gun has been used for the model simulation and experimental verification. The dynamic simulation was conducted and then the results were compared with the corresponding experimental data. The model simulation results are very close to the experimental results. This study aims to survey the influence of various parameters on gun stability in the shooting. It is possible to apply these results to portable automatic guns.
本文基于拉格朗日定理和多体系统动力学理论，提出了一种考虑人体影响的射击-武器系统射击动力学模型的建立方法。在动力学模型中，通过在x、y和z轴上采用弹性阻尼连杆来解决炮手的影响。该动力学模型是为便携式气控冲锋枪创建的，包含三个七个自由度的固体。采用7.62 mm AKM冲锋枪进行了模型仿真和实验验证。进行了动态仿真，并与相应的实验数据进行了比较。模型仿真结果与实验结果非常接近。本研究旨在探讨射击过程中各参数对枪械稳定性的影响。这些结果可以应用于便携式自动枪。
{"title":"Effect of Some Structural Parameters on Firing Stability of Shooter-Weapon System","authors":"Van Bien Vo, Van Phuc Ta, Martin Macko","doi":"10.3849/aimt.1487","DOIUrl":"https://doi.org/10.3849/aimt.1487","url":null,"abstract":"This article presents a method to establish the dynamic model of the Shooter-weapon system when firing based on Lagrange’s theorem and the theory of multibody system dynamics, in which the influence of the human body was taken into account. In the dynamic model, the influence of the gunner is solved by using elastic-damping links in the x, y and z axes. The dynamic model is created for a portable gas-operated submachine gun and contains three solids with seven degrees of freedom. The 7.62 mm AKM submachine gun has been used for the model simulation and experimental verification. The dynamic simulation was conducted and then the results were compared with the corresponding experimental data. The model simulation results are very close to the experimental results. This study aims to survey the influence of various parameters on gun stability in the shooting. It is possible to apply these results to portable automatic guns.","PeriodicalId":39125,"journal":{"name":"Advances in Military Technology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45290185","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The article deals with aviation disasters from 1948 to the present and it involves disasters of military jet fighter, fighter-trainer and trainer aircraft. It focuses on the role of human factors of the flight personnel. Based on the extensive analyses of circumstances and causes of individual aviation occurrences, root causes of factors that have endangered the lives of pilots in carrying out their work are determined. To conclude, recommendations are given to reduce or in many cases even to eliminate the effects of these factors on flight safety.
{"title":"Human Factors in Aviation Disasters of Military Jet Aircraft of Czechoslovakia and the Czech Republic","authors":"O. Zavila","doi":"10.3849/aimt.01451","DOIUrl":"https://doi.org/10.3849/aimt.01451","url":null,"abstract":"The article deals with aviation disasters from 1948 to the present and it involves disasters of military jet fighter, fighter-trainer and trainer aircraft. It focuses on the role of human factors of the flight personnel. Based on the extensive analyses of circumstances and causes of individual aviation occurrences, root causes of factors that have endangered the lives of pilots in carrying out their work are determined. To conclude, recommendations are given to reduce or in many cases even to eliminate the effects of these factors on flight safety.","PeriodicalId":39125,"journal":{"name":"Advances in Military Technology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43598583","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Although it is widely believed that the space sector is one of the pillars of national security, in practice cosmic systems exist somewhat outside the area of critical infra-structures discussion. Cybersecurity of space systems does not differ significantly from industrial cybersecurity, however, the uniqueness of the sector and space technologies means that its vulnerability to digital incidents depends on a number of factors that does not occur anywhere else. The purpose of the article is to defend the thesis that space systems are the weakest link in critical infrastructure systems, because the level of their cybersecurity is still disproportionate to the level of their technological ad-vancement.
{"title":"Space Systems as the Weakest Link","authors":"Sławomir Dygnatowski","doi":"10.3849/aimt.01409","DOIUrl":"https://doi.org/10.3849/aimt.01409","url":null,"abstract":"Although it is widely believed that the space sector is one of the pillars of national security, in practice cosmic systems exist somewhat outside the area of critical infra-structures discussion. Cybersecurity of space systems does not differ significantly from industrial cybersecurity, however, the uniqueness of the sector and space technologies means that its vulnerability to digital incidents depends on a number of factors that does not occur anywhere else. The purpose of the article is to defend the thesis that space systems are the weakest link in critical infrastructure systems, because the level of their cybersecurity is still disproportionate to the level of their technological ad-vancement.","PeriodicalId":39125,"journal":{"name":"Advances in Military Technology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47581474","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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