Generalised Model for Aircraft Vulnerability by Different Weapon Systems

The authors earlier model for the vulnerability of aircraft where aircraft was considered as a combination of cylinder, cones and wedges has been extended to the case when structural data of aircraft as well as its vital parts are given in the form of three-dimensional curvilinear triangles. In the case of VT -fused ammunition, spherical normal distribution has been used to estimate the landing probability of the shell in a cylindrical vicinity region around the aircraft. Kill criteria of vital parts have been redefined

Interaction of Explosive Shocks with Airborne Cylindrical Targets of Elliptical

A theoretical model to find pressure-space history around a cylindrical target of elliptical cross-section has been presented for assessing the damage by warheads exploding in the vicinity of an airborne vehicle. The energy hypothesis has been used to find the attenuation law from a point explosion. The Whitham-Bryson and Gross theory for shock interaction has been modified to take into account the finite strength of incident shock. The theoretical results have also been compared with Heilig's experimental results

A Note on the New Theory of Shock Dynamics

The new theory of shock dynamics proposed by Ravindran and Prasad has been considered with initial values taken from the similarity solution for a single conservation equation and the results have been compared with those obtained by Lax-Wendroff finite difference method

A Model for Estimation of Aircraft Attrition from Various Ground Air Defence Weapons

A computer-based mathematical model is developed for the estimation of assessment of damage inflicted on an aircraft due to a ground-base air defense gun. It is assumed that the aircraft is approaching the target from an arbitrary direction and does not change it's trajectory during gun firing. Dimension of aircraft and trajectory of warhead are assumed to be known. Damage to aircraft is caused due to blast as well as fragments. Aircraft is assumed to be killed if one of its vital parts has been killed

Mathematical Modelling of Damage of Aircraft Skin Panels Subjected to Blast Loading

A mathematical model for assessing the damage to an aircraft due to blast from conventional ammunition has been developed. The minimum distance of the point of explosion from the aircraft for its permanent damage for a reference explosion has been obtained depending upon the dimensions (thin plate or thin cylindrical shell) of the structural elements

Extended near field modelling and droplet size distribution for fuel air explosive warhead

"A theoretical model is developed for the prediction of the mean-mass diameter of droplets produced by the fragmentation of liquid fuel sheet and film in a fuel-air explosive (FAE) device after the detonation of the central burster charge. This model does not contain arbitrarily assumed values for the instabilities as in presently available models. Also, a distribution model for the initial distribution of the droplet diameter, which depends on the design parameters of the FAE device, is presented.

Living Gymnosperms in Uttar Pradesh in India and their Economic Importance

The paper presents a preliminary report on the distribution of Living Gymnosperms in Uttar Pradesh, State of India. As per the records available at BSA and exploration 19 species, 11 genera, 1 variety under 7 families have been recorded so for area under study. Economic uses of some gymnosperms are also given

Spectroscopic Characterization of GaAs and AlxGa1 – xAs / AlyGa1 – yAs Quantum Well Heterostructures

This work presents the results of the characterization of GaAs and AlxGa1 – xAs / AlyGa1 – yAs quantum well hetero-structures growth by MOVPE system. The main goal is to explore the ability of characterization techniques for multilayer structures like quantum wells. The characterization was performed using photoreflectance spectroscopy, surface photovoltaic spectroscopy and X-ray diffraction. The experimental results are verified by numerical simulation. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3193

Approximate Closed-Form Solution for projectile Trajectory and its Applications to lead Angle Computations

In this paper, an approximate closed-form solution for trajectories of ballistic projectiles is derived. The assumption made in this derivation is to neglect the variation of the elevation angle along the trajectory in a small interval of time. The closed-form solution has been used to develop the 3-logarithm for a lead angle computation as well as faster computation of trajectories. The fact that one of the analytical expressions although complex, is invertible and is made use of in the algorithm

Effect of Groundwater Pumping on Seawater Intrusion in Coastal Aquifers

Many aquifers around the globe are located in coastal areas and are thus subjected to the seawater intrusion phenomenon. The growth of population in coastal areas and the conjugate increase in human, agricultural, and industrial activities have imposed an increasing demand for freshwater. This increase in water demand is often covered by extensive pumping of fresh groundwater, causing subsequent lowering of the water table (or piezometric head) and upsetting the dynamic balance between freshwater and saline water bodies. The classical result of such a development is seawater intrusion. This paper presents a review for the seawater intrusion phenomenon in coastal aquifers. The effect of pumping activities on the seawater intrusion in the Nile Delta aquifer of Egypt is investigated. It was concluded that any additional pumping should be located in the middle Delta and avoided in the eastern and western sides of the Delta