A Model for Shaped Charge Warhead Design

A model for shaped charge warhead design was developed. The model is incorporated in the computer code - CUMUL. The code includes detonation wave profile estimation, liner collapse, arrival of collapsed liner to the centerline of shaped charge, jet creation and jet breakup. The penetration phenomena are discussed and governing equations are presented. Two cases dealing with the target type are included: homogenous and non-homogeneous targets. For the purpose of verifying CUMUL, a set of 20 specimens of shaped charges was tested. The tests were directed to investigate the effect of cone apex angle and stand-off distance on the performance of shaped charge. From the comparison between experiments and CUMUL results, it was concluded that CUMUL program shows a good agreement with the experiments. That enables it to be a powerful tool for shaped charge warhead design

Genotypic specifics sugar beet varieties depending on different crop density

Šećerna repa u Srbiji je jedna od najvaţnija biljka za industrijsku preradu i gaji se na površinama od 60.000-75.000 hektara. Program istraţivanja koncipiran je tako da omogući dobijanje najznaĉajnijih podataka iz oblasti veoma vaţnog segmenta agrotehnike, a to je odnos novih sorti prema uslovima spoljne sredine, kao i mogućnosti povećanja gustine useva u cilju povećanja genetiĉkog potencijala rodnosti šećerne repe. Nauĉna istraţivanja izvoĊena su u toku 2011., 2012., i 2013. godine na eksperimentalnim parcelama PSS Instituta „Tamiš“ u Panĉevu na zemljištu tipa karbonatni ĉernozem na lesnoj terasi. Dvofaktorijalni poljski mikroogledi postavljeni su po metodi potpuno sluĉajnog blok sistema u ĉetiri ponavljanja, a materijal u istraţivanjima predstavljala su ĉetiri genotipa šećerne repe: sorte (Esprit, Belinda, Gina i Chiara). MeĊuredna rastojanja izmeĊu biljaka u redu bila su sledeća: (100.000 biljaka po hektaru; 130.000 biljaka po hektaru i 160.000 biljaka po hektaru). Program istraţivanja realizovan je u pet faza, i to gajenjem biljaka šećerne repe u poljskim mikroogledima, analizom meteoroloških podataka, laboratorijskim analizama zemljišta, hemijskom analizom korenova šećerne repe i statistiĉkom obradom dobijenih podataka. Gustina useva je znaĉajno uticala na prinos nadzemne mase, ukupni prinos i prinos kristanog šećera, a nije znaĉajno uticala na tehnološki kvalitet šećerne repe (sadrţaj šećera, kalijuma, natrijuma i alfa-amino-azota u korenu). Najveći ukupni prinos korena i prinos kristalnog šećera kod svih sorti bio je u srednjoj gustini useva (130.000 biljaka po hektaru). Sorta je prema genetskim karakteristikama pokazala sledeće rezultate: Najveću digestiju i prinos kristalnog šećera imala je šećernatoslatka sorta Gina. Sorta Belinda se istakla najboljom tehnološkom kvalitetom korena, imala je najveći koeficijent iskorišćenja i najmanji sadrţaj kalijuma, natrijuma i alfa-amino-azota u korenu. Najveći prinos korena šećerne repe imala je prinosna sorta Chiara.Sugar beet is one of the most important plants for industrial processing and grown on an area of 60.000-75.000 hectares. The research programis designed to enable the provision of the most important data in the field is very important segment of agricultural technology, and that is the relationship of new varieties according to the environmental conditions, as well as the possibility of increasing plant density in order to increase the yield potential of sugar beet. Scientific studies have been performed in 2011., 2012., and 2013. on experimental plots PSS Institute“Tamis" in Pancevo on calcareous chernozem soil on theloess terrace. Two factorial micro field are set by the method of completely randomized block design with four replications, and the material in this study represented the four genotypes of sugar beet varieties (Esprit, Belinda, Gina and Chiara). Row spacing between plants in the row were the following: (100.000 plants per hectare; 130.000 plants per hectare and 160.000 plants per hectare). The research program was implementedin five phases, and to growing sugar beet plants in the field micro-trials, analysis of weather data, laboratory analysis of soil, chemical analysis of sugar beet root sand statistical analysis of the obtained data. The crop density is significantly affected the yield stalk weight, total yield and yield crystal sugar, and had no significant effecton the technological quality of sugar beet (sugar content, potassium, sodium and alpha-amino-nitrogen in the root). The highest total root yield and sugar yield in all cultivars was high plant density (130.000 plants per hectare). Variety is the genetic characteristics showed the following results: The highest digestion and sugar yield had variety Gina. Variety Belinda had the best technological quality of roots, had the highest coefficient of utilization and minimum content of potassium, sodium and alpha-amino-nitrogen in the root. The highest yield of sugar beet root yield had a variety Chiara

Genotypic specifics sugar beet varieties depending on different crop density

Šećerna repa u Srbiji je jedna od najvaţnija biljka za industrijsku preradu i gaji se na površinama od 60.000-75.000 hektara. Program istraţivanja koncipiran je tako da omogući dobijanje najznaĉajnijih podataka iz oblasti veoma vaţnog segmenta agrotehnike, a to je odnos novih sorti prema uslovima spoljne sredine, kao i mogućnosti povećanja gustine useva u cilju povećanja genetiĉkog potencijala rodnosti šećerne repe. Nauĉna istraţivanja izvoĊena su u toku 2011., 2012., i 2013. godine na eksperimentalnim parcelama PSS Instituta „Tamiš“ u Panĉevu na zemljištu tipa karbonatni ĉernozem na lesnoj terasi. Dvofaktorijalni poljski mikroogledi postavljeni su po metodi potpuno sluĉajnog blok sistema u ĉetiri ponavljanja, a materijal u istraţivanjima predstavljala su ĉetiri genotipa šećerne repe: sorte (Esprit, Belinda, Gina i Chiara). MeĊuredna rastojanja izmeĊu biljaka u redu bila su sledeća: (100.000 biljaka po hektaru; 130.000 biljaka po hektaru i 160.000 biljaka po hektaru). Program istraţivanja realizovan je u pet faza, i to gajenjem biljaka šećerne repe u poljskim mikroogledima, analizom meteoroloških podataka, laboratorijskim analizama zemljišta, hemijskom analizom korenova šećerne repe i statistiĉkom obradom dobijenih podataka. Gustina useva je znaĉajno uticala na prinos nadzemne mase, ukupni prinos i prinos kristanog šećera, a nije znaĉajno uticala na tehnološki kvalitet šećerne repe (sadrţaj šećera, kalijuma, natrijuma i alfa-amino-azota u korenu). Najveći ukupni prinos korena i prinos kristalnog šećera kod svih sorti bio je u srednjoj gustini useva (130.000 biljaka po hektaru). Sorta je prema genetskim karakteristikama pokazala sledeće rezultate: Najveću digestiju i prinos kristalnog šećera imala je šećernatoslatka sorta Gina. Sorta Belinda se istakla najboljom tehnološkom kvalitetom korena, imala je najveći koeficijent iskorišćenja i najmanji sadrţaj kalijuma, natrijuma i alfa-amino-azota u korenu. Najveći prinos korena šećerne repe imala je prinosna sorta Chiara.Sugar beet is one of the most important plants for industrial processing and grown on an area of 60.000-75.000 hectares. The research programis designed to enable the provision of the most important data in the field is very important segment of agricultural technology, and that is the relationship of new varieties according to the environmental conditions, as well as the possibility of increasing plant density in order to increase the yield potential of sugar beet. Scientific studies have been performed in 2011., 2012., and 2013. on experimental plots PSS Institute“Tamis" in Pancevo on calcareous chernozem soil on theloess terrace. Two factorial micro field are set by the method of completely randomized block design with four replications, and the material in this study represented the four genotypes of sugar beet varieties (Esprit, Belinda, Gina and Chiara). Row spacing between plants in the row were the following: (100.000 plants per hectare; 130.000 plants per hectare and 160.000 plants per hectare). The research program was implementedin five phases, and to growing sugar beet plants in the field micro-trials, analysis of weather data, laboratory analysis of soil, chemical analysis of sugar beet root sand statistical analysis of the obtained data. The crop density is significantly affected the yield stalk weight, total yield and yield crystal sugar, and had no significant effecton the technological quality of sugar beet (sugar content, potassium, sodium and alpha-amino-nitrogen in the root). The highest total root yield and sugar yield in all cultivars was high plant density (130.000 plants per hectare). Variety is the genetic characteristics showed the following results: The highest digestion and sugar yield had variety Gina. Variety Belinda had the best technological quality of roots, had the highest coefficient of utilization and minimum content of potassium, sodium and alpha-amino-nitrogen in the root. The highest yield of sugar beet root yield had a variety Chiara

A Model for Explosive Reactive Armor Interaction with Shaped Charge Jet

Study of interaction of explosive reactive armor (ERA) with shaped charge jet is the basis for evaluation of the effectiveness of ERA. The physically based theoretical model of this interaction is given. It is incorporated in the NERA computer code. The influences of backward moving plate and forward moving plate thickness, explosive layer thickness, jet attack angle, and distance between ERA and main armor are investigated. The comprehensive analysis of a longitudinal point of impact effect on ERA efficiency, based on NERA code calculations, is presented. Computational results of NERA code are compared with experimental data. The computational and experimental results of penetration in the steel armour target are in good agreement. The developed code enables optimization of explosive reactive armor characteristics

Determination of Pressure Profiles Behind Projectiles During Interior Ballistic Cycle

The determination of pressure profiles behind a projectile has been a subject of investigations for more than 70 years. For lumped parameter models it was especially important to determine the pressure on the projectile base, pressure on the chamber base, and pressure for the propellant burning law. In the paper two analytical methods and one numerical method are considered. The analytical methods of proportionate expansion and two-phase mixture are studied. Pressure profiles are also computed numerically by TWO Phase Interior Ballistics (TWOPIB) code, which is based on the model of two-phase flow of solid propellant and its products of combustion, treated as separate phases with appropriate conservation laws and interactions between phases. Through comparison with experimental results on the real weapon system TWOPIB code showed great advantages over analytical methods

Reactive active propulsion

A new interior ballistic concept of reactive active projectile propulsion is analyzed. During acceleration in a rocket launcher the projectile is separated from the rocket engine chamber by the action of active granular propellant charge located behind the projectile stabilizer. The projectile is then additionally accelerated with corresponding deceleration of the rocket engine chamber. The active propellant charge is initiated by the pyrotechnic delay during the rocket engine function. The interior ballistic cycle terminates near the front of the rocket launcher by the extraction completion of the projectile stabilizer from the launching tube. A theoretical model for reactive active propulsion is presented. The model includes simultaneous function of rocket engine and active propellant charge in the launcher. The computer code RAP (Reactive Active Propulsion) for interior ballistic cycle of reactive active projectiles is developed. The parametric study is carried out based on the RAP code calculations. The moment of active charge initiation by the pyrotechnic train is found to be very important parameter for regular function of the system. Computational results show possibilities of reactive active propulsion interior ballistic concept to significantly increase projectile performance

A Model for Explosive Reactive Armor Interaction with Shaped Charge Jet

Study of interaction of explosive reactive armor (ERA) with shaped charge jet is the basis for evaluation of the effectiveness of ERA. The physically based theoretical model of this interaction is given. It is incorporated in the NERA computer code. The influences of backward moving plate and forward moving plate thickness, explosive layer thickness, jet attack angle, and distance between ERA and main armor are investigated. The comprehensive analysis of a longitudinal point of impact effect on ERA efficiency, based on NERA code calculations, is presented. Computational results of NERA code are compared with experimental data. The computational and experimental results of penetration in the steel armour target are in good agreement. The developed code enables optimization of explosive reactive armor characteristics

Reactive active propulsion

A new interior ballistic concept of reactive active projectile propulsion is analyzed. During acceleration in a rocket launcher the projectile is separated from the rocket engine chamber by the action of active granular propellant charge located behind the projectile stabilizer. The projectile is then additionally accelerated with corresponding deceleration of the rocket engine chamber. The active propellant charge is initiated by the pyrotechnic delay during the rocket engine function. The interior ballistic cycle terminates near the front of the rocket launcher by the extraction completion of the projectile stabilizer from the launching tube. A theoretical model for reactive active propulsion is presented. The model includes simultaneous function of rocket engine and active propellant charge in the launcher. The computer code RAP (Reactive Active Propulsion) for interior ballistic cycle of reactive active projectiles is developed. The parametric study is carried out based on the RAP code calculations. The moment of active charge initiation by the pyrotechnic train is found to be very important parameter for regular function of the system. Computational results show possibilities of reactive active propulsion interior ballistic concept to significantly increase projectile performance

Analysis of parameters influencing the pressure and temperature distribution in the gun bore evacuator

The purpose of a gun bore evacuator on the turret-mounted gun barrel is to prevent the entry of the gaseous products of gun propellant combustion into the turret compartment of the vehicle after the breech block opening. The mathematical model which takes into account all of the main parameters influencing the pressure change inside the cylinder of the evacuator was developed. Differential equations that describe the flow field through the nozzle in the barrel wall and in the cylinder of the evacuator were solved numerically. Furthermore, the numerical simulations were performed using the ANSYS FLUENT in order to analyze the phenomena occuring in the evacuator during the charge and discharge cycles which are difficult to be taken into account with the analytical model. Aforementioned simulations were performed with the 3-D model of the evacuator and with the initial and boundary conditions obtained from the interior ballistic calculations. In order to find the change of the static pressure in the cylinder of the gun bore evacuator, the experimental research was performed. The comprehensive comparison between the numerical results and the experimental data has shown good agreement. Based upon this analysis, the influence of the evacuator’s main design parameters on the pressure distribution and the temperatures in the critical zones was determined. The influence of the propellant’s initial temperature on the pressure and wall temperatures in the evacuator was also analyzed, due to the wide range of gun operating temperatures and the possibility of erosion occurrenc