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The purpose of this paper is to present the aerodynamic analysis and external ballistics modeling used in the development of a rocket-target for short range air defence missile systems.

A computational fluid dynamics (CFD) analysis of the airflow around the rocket-target was carried out to estimate the drag, which was needed to develop a mathematical model for external ballistics of the rocket-target. Field-experimental testing was conducted to compare the model results to the data obtained experimentally using various additional measurement techniques such as global positioning system (GPS) coordinates marking of the crash and launch sites, air defence surveillance radar tracking and installing equipment for telemetric data capturing and transmission.

Various ballistic parameters such as the velocity and trajectory of the rocket-target were obtained taking into account the CFD analysis results and internal ballistics data. The field-experimental testing showed a good agreement between the model results and the results obtained by the experimental techniques.

The presented computational models and the experimental techniques could be used in future developments of similar aircraft.

This paper presents a research approach for developing a rocket-target. The results of the research were used as a basis for developing a rocket-target for short range air defence rocket systems. The developed rocket-target was successfully implemented in practice.

For one man adequately to cover the whole practical and theoretical field of rocket propulsion is well‐nigh impossible: in view of this, the present work has been compiled from the work of four authors, three of whom are Belgian and one (Barrère) French. The whole, which originated in a series of lectures organized by M. Jaumotte, forms a fairly comprehensive survey of the field. Indeed, by its inclusion of three chapters on external ballistics it goes outside the limits of rocket propulsion as normally understood.

The purpose of this study is to design and develop new spiral head projectiles undergoing ballistics impact.

The introduction of the rifled barrel in firearms made projectile spin during its flight path. The central translational velocity (impact velocity) is one parameter to defeat/penetrate the target in the penetration process. Another important parameter considered to be the shape of the projectile. Many types of projectile shapes have been designed to defeat the target. In the recent years, ogival nose shape is one of the well-known projectile shapes in use abundantly. The present research is made to design the nose shape so as to use the spin during the penetration of target effectively. In this study, a new spiral head projectile shape is proposed and designed, which uses the rotation of projectile (spin) for penetrating the Al7075-T6 target. When the ogive and new spiral head projectile is impacted on Al 7075-T6 target of 12.5 mm, 18 mm thicknesses at ordnance velocities, the residual velocity is evaluated numerically using ANSYS/Explicit Dynamics at normal impact condition. Two projectile materials, steel 4340 and tungsten alloy, are used as projectile materials. Along with the translational velocity, rotation velocities (spin rate) 13,000, 26,000 and 52,000 rad/s also provided to projectile. The residual velocities verses spin rate are plotted for different spiral angle projectiles for impact velocities 1,000–1,500 m/s, at normal impact conditions on the Al 7075-T6 target. Compared with the ogive nose projectile, the proposed new spiral head projectile made of tungsten alloy is significantly effective.

Spiral head projectile having tungsten alloy material gives encouraging results at 12.5 mm target thickness. The new spiral head projectile is damaged partially. At 18 mm target thickness impact conditions, it is observed that the projectile head is completely damaged. The effectiveness of spiral head projectile on a target plate thickness of 18 mm is considered to study the impact condition.

All the above results need to be experimentally verified. However, the basic numerical model used in the present study, i.e. the basic ogive nose numerical model with only translational energy, is well validated with penetration theory available in literatures.

The designed new spiral head projectile is only effective with tungsten alloy material within considered design parameters. For steel 4340 material, the spiral head projectile is less effective than the ogive nose projectile. In tungsten alloy projectiles, by observing all considered spiral angles, 30-degree spiral angle projectile gives the best performance at most of the considered impact velocity conditions.

The proposed research outputs are original, innovative and, have lot of importance in defence applications particularly in arms and ammunitions.

This book, published under the authority of the Royal Aeronautical Society, contains abundant information on all aspects of current landing gear design. In collecting this information, most of the British, and many foreign, installations have been analysed. Through his considerable experience the author is well qualified to offer much valuable advice, sometimes contentious, on proven solutions and pitfalls to avoid. The substance is presented in an admirably forthright manner and, being well supported by relevant facts, figures and references, cannot fail to recommend itself to the expert and novice alike. In a work of this nature where there is so much ground to be covered, a good balance is achieved and digression is limited by directing the reader to other published information on the appropriate occasions. In his criticism, the reviewer has in mind the requirements of the ‘young engineer or student to whom the book is addressed’.

This paper aims to show the implementation in the terrestrial trunked radio (TETRA)-based sensor network. The publicly available data show that, in Serbia, the annual damage caused by hailstorms in the past seven years has been estimated almost at an average level of 40m of euros. As the amount of hail was not changed, the hail suppression system of the Republic of Serbia has to be improved, both technically and organizationally, to get better efficiency and protection and to reduce the damage.

In this paper, the authors show the implementation and improvements in the modern terrestrial trunked radio (TETRA)-based sensor network, and they propose the scientific use of sensors for remote control of automatic hail suppression rocket stations.

The authors’ idea is that TETRA should be used as an operational and official telecommunicating system for hail suppression activities units. A number of sensors, connected in a network, are used to maintain a high-quality functioning of this digital radio system, managed remotely and controlled either by operators or automatically.

The presented study with a real example attempts to explain as to how the system functions and how it can improve hail suppression activities.

Two methods of assessing probable response to fatigue are in common use. The safe life method is based on the expected loading history, laboratory tests and a safety factor.

Effect of rocket and launcher design parameters on the maximum height obtainable in vertical flight. Comparison of costs for single‐ and two‐stage rockets. If efficiencies of around 100,000 ft./lb. payload/lb. propellent can be realized in practice, small solid propellent rockets should prove economical for routine meterological use.

This unusual book gives a combined account of three different branches of dynamics, dealing with particles, fluids and solid bodies. The preface explains the history of the course at the Massachusetts Institute of Technology on which the book is based. When instruction in aeronautical engineering was started at M.I.T., some forty years ago, the branch of the subject that was most fully developed from a rational viewpoint was the theory of dynamic stability. The students, with only an elementary training in mathematics and mechanics, found this theory of stability too difficult to grasp, and a course was therefore started to bridge the gap between the mathematics and mechanics that the students already knew and the complex problems of aircraft stability.

Forensic crime labs play an important role in the criminal justice system’s response to violent gun crimes in the USA. The purpose of this paper is to describe the methods of firearms analysis including ballistics imaging and proposed best practices for investigating gun crimes. A separate line of research has begun to explore the structure of forensic labs and how structure impacts lab performance.

To date, however, proposed best practices in firearms investigation have not been empirically tested within crime labs. The authors address this gap in the literature by using a mediation model examining organizational correlates of a limited number of tasks (identified by Peter Gagliardi’s 13 Critical Tasks) believed to enhance our final dependent measures, forensic crime lab outcomes (NIBIN acquisitions and hits). The authors examine, therefore, the relationship between organizational correlates, collected from a sample of publicly funded labs in the USA, on several of Gagliardi’s tasks and then explore the relationship of those tasks on our outcome variables: NIBIN acquisitions and hits.

Results indicate agency size and number of agencies serviced by a lab are significant factors associated with our mediating variables (Gagliardi’s tasks). Communication was identified as a significant task associated with achieving NIBIN acquisitions and hits. In general, this study underscores the importance of communication between labs and other institutional constituents for increasing ballistics imaging outputs. Furthermore, findings provide partial support for Gagliard’s tasks, by highlighting the role of enhanced communication on organization-based performance outcomes.

This study is the first to examine the mediating effect of Gagliardi’s tasks on the organizational performance of ballistics imaging systems within crime labs. In addition, this study examines the influence of organizational correlates on these mediating tasks.

Having taken up our position on the above definition of this fundamental point, which closes the long‐standing discussion between upholders of the airscrew and those of the reaction system (just as in earlier days the distinction between impulse and work closed the classic discussion between the followers of Leibnitz and Descartes), we must now admit, without going into details, that this supposed attainment of equal efficiencies cannot be considered easy, if even possible, for the normal speeds of flight. It must also be admitted that a power unit, consisting of engine, compressor and jet, is at first sight a unit more complex, heavier and more bulky than the ordinary engine‐airscrew unit which has now been reduced to a high degree of simplicity and neatness. There is no doubt at all that in the sphere of the sub‐acoustic velocities the airscrew will reign supreme.