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This paper presents the fragility analysis of the safety and reliability of the damping devices cover of nuclear power plant under impact of the container of nuclear fuel of type TK C30 drop. The finite element idealization of nuclear power plant structure is used in space. The steel pipe damper system is proposed for dissipation of the kinetic energy of the container free fall. The experimental results of the shock-damper basic element behaviour under impact loads are presented. The Newmark integration method is used for solution of the dynamic equations. The fragility analysis of the damping devices was realized in MathCAD, FReET and ANSYS software. [ABSTRACT FROM AUTHOR]

Many munitions react violently when subject to Fragment Impact (FI) threats. Previous efforts have identified materials that mitigate / partially mitigate munitions FI response at 6000fps, but have had shortfalls at 8300fps. While existing materials are known to improve / partially mitigate munitions' FI response at 8300fps, the materials / configurations are costly, both logistically and financially. O ne f acet o f s uccessful m itigation t hat h as p roven t o r esult i n l ess v iolent r eactions i s the breakup and dispersion of the steel fragment, resulting in reduced velocity, spreading the imparted kinetic energy into the explosive, thereby reducing the power density. It is conceived that high density and layered protection materials provide the ballistic properties needed to fracture and disperse the fragment projectile. There is a shortfall in empirical data demonstrating this fragment breakup as a result of different protection schemes. This paper will discuss the methodology for the parametric study, data analysis, and results of the breakup and dispersion of an 8300fps standard NATO mild steel fragment (IAW STANAG 4496), after impacting baseline and armor targets at specified thicknesses, based on experimental testing and comparative modeling. [ABSTRACT FROM AUTHOR]

The supercompression of matter caused by gravitational coupling, or self-gravitational forces, leads to density growth by several orders in magnitude. Keeping in mind the importance of self-gravitation in astrophysical processes like supernovae star evolution we consider it reasonable to develop a numerical technique based on the consistent approximation to the terms describing gravitational energy transfer into the kinetic energy of a matter in the star along its life cycle. In the paper, we propose an integrally-consistent difference scheme that utilizes the method of support difference operators thus providing a possibility to conform the balance between kinetic and gravitational energy increments or losses. According to this method, we use the result of the total gravitational energy varying and construct the symmetrized strain rate tensor as the base operator. The result of varying the gravitational energy of the system is a discrete convolution of the Newton gravitational tensor in the difference media under study, which exhaustively answers all the gravitational processes unfolding against the background of the hydrodynamic motion of matter. The symmetrized strain tensor governs the kinematic motion in a considered system. The conjugate operator related to the convolution of these tensors automatically gives the approximation to the gravitational forces acting in the interior of the balance volume of the difference model built via the support operator approach. [ABSTRACT FROM AUTHOR]

When modeling flows of an incompressible fluid, it is convenient sometimes to use the method of discrete vortices (MDV), where the continuous vorticity field is approximated by a set of discrete vortex elements moving in the velocity field. The vortex elements have a clear physical interpretation, they do not require the construction of grids and are automatically adaptive, since they concentrate in the regions of greatest interest and successfully describe the flows of a non-viscous fluid. The possibility of using MDV in simulating flows of a viscous fluid was considered in the previous papers using the examples of flows past bodies with sharp edges with the no-penetration condition at solid boundaries. However, the appearance of vorticity on smooth boundaries requires the no-slip condition to be met when MDV is realized, which substantially complicates the initially simple method. In this connection, an approach is considered that allows solving the problem by simple means. [ABSTRACT FROM AUTHOR]

Hydrography and mixing properties in the shallow waters of the Komodo National Park waters were investigated from nearly one tidal cycle CTD profiles. The mixing properties were estimated using an improved Thorpe method by inspecting instabilities observed in the density profile. Strong semidiurnal M2 tidal driven watermass dynamics were observed, with a relatively homogenous vertical profile seawater properties. Temperature and salinity fluctuate from 25 to 28 oC and 34.15 to 34.30 psu, respectively. The pH also fluctuates around 0.1 along with the periodicity of low and high tide. The oxycline layer was observed at around 10 m depth. The typical mean values of turbulent kinetic energy dissipation rates and vertical diffusivity were in the order of 10−10-10−8 m2s-3 and 10-6-10-5 m2s-1, respectively. There is an enhancement of chlorophyll-a during the transition period from high/low tide to low/high tide which is related to intensive dissipation rate and vertical diffusivity. [ABSTRACT FROM AUTHOR]