Scaling Effects in the Impact Resistance of Flat and Cylindrical Samples from Composite Materials

The scaling factors in the problems of assessing the resistance to high-speed impact of plates and shells are analytically determined. Numerical experimentation shows the possibility of applying certain scaling factors in assessing the impact resistance of laminated plates and shells from materials with orthotropic properties.     

A method for calculating the laser rocket engine thermal state based on the optical discharge with numerous plasma formations

A method is presented for calculating the thermal state of the laser rocket engine (LRE) structure with numerous plasma formations in the absorption chamber. The results of evaluating radiant heat fluxes and the temperature of the LRE structure walls with regard for convective and conductive heat exchange are given; the actions of a heat flux with the specified distribution density on the structure surface are considered as functions of time and thermal radiation, that is due to the temperature and optical properties of a radiating body. It is shown that working process organization in the absorption chamber on the basis of numerous plasma formations makes it possible to produce a uniform profile of the heat flux distribution along the absorption chamber axis and thus reduce a possibility of separate structure sections overheating.     

Improvement of the real time total electron content based on the International Reference Ionosphere model

One of the methods to adapt the International Reference Ionosphere model to real time conditions is to use instantaneous values of the critical frequency of the ionosphere foF2. It is shown that there can be large discrepancies between model and experimental values of the total electron content TEC after this adaptation. Improvement can be provided by the use of an empirical model of the ionospheric slab thickness τ. This conclusion is based on analysis of contributions of various correction factors connected with foF2 and τ into discrepancies between model and experimental values of TEC.     

Estimation of the Combustion Chamber Shell Working Capacity for the Reusable Liquid-Propellant Rocket Engine

On the base of the simplified analytical model for the bimetallic shell of the combustion chamber of the reusable liquid-propellant rocket engine, the analysis of the loading of connectors between the shell walls and the accumulation of inelastic deformations in the inner wall material was carried out. The results obtained can be used for evaluation of the maximal number of engine operation cycles.     

A study on radio-loud interacting/non-interacting CMEs-associated SEPs and solar flares

We have established a data set of 58 major hybrid SEP events associated with meter-to-decahectometer wavelength (m-to-DH) type II bursts, solar flares, and radio-load CMEs during the period of 1997–2014. The main focus of our study is to address the following two questions: Does the interaction of CMEs play a role in the enhancement of SEP intensity? Is there any difference in the seed population, and parent eruptions in the SEP events with and without CME interactions? Hence, the sample of 58 events is classified into two sets: (i) 35 non-interacting-CME-associated SEP events; (ii) 23 interacting-CME-associated SEP events. All the characteristics of SEPs, their associated CMEs/flares and the relationships between them are statistically analyzed and compared. Some of the basic attributes and relative elemental abundances (Fe/O ratios) of the both the sets are also compared. The results indicate that the seed particles in non-interacting-CME-associated SEP events are mostly from solar wind/coronal materials. But in the case of interacting-CME-associated SEP events, it may be associated with both flare material from preceding flares and coronal materials from solar wind/preceding CMEs. The correlation studies reveal that there are clear correlations between logarithmic peak intensity of SEP events and properties of CMEs (space speed: cc?=?0.56) and solar flares (peak intensity: cc?=?0.40; integrated flux: cc?=?0.52) for non-interacting-CME-associated SEP events. But these correlations are absent for the interacting-CME-associated events. In addition, the results suggest that interaction of primary CMEs with their preceding CMEs plays an important role in the enhancement of peak intensity of SEPs at least for a set of m-to-DH type II bursts associated SEP events.     

Inferring Nighttime Ionospheric Parameters with the Far Ultraviolet Imager Onboard the Ionospheric Connection Explorer

The Ionospheric Connection Explorer (ICON) Far Ultraviolet (FUV) imager, ICON FUV, will measure altitude profiles of OI 135.6 nm emissions to infer nighttime ionospheric parameters. Accurate estimation of the ionospheric state requires the development of a comprehensive radiative transfer model from first principles to quantify the effects of physical processes on the production and transport of the 135.6 nm photons in the ionosphere including the mutual neutralization contribution as well as the effect of resonant scattering by atomic oxygen and pure absorption by oxygen molecules. This forward model is then used in conjunction with a constrained optimization algorithm to invert the anticipated ICON FUV line-of-sight integrated measurements. In this paper, we describe the connection between ICON FUV measurements and the nighttime ionosphere, along with the approach to inverting the measured emission profiles to derive the associated O⁺ profiles from 150–450 km in the nighttime ionosphere that directly reflect the electron density in the F-region of the ionosphere.     

Simulation of <Emphasis Type="Italic">Z</Emphasis>-crimp shaping with the use of the ansys finite element software

A finite element model of the Z-crimp shaping from a hard sheet blank is developed and a number of calculations using the ANSYS finite element software is conducted. The calculations are carried out in the framework of elastoplastic behavior of the blank material using the classical model of bilinear kinematic (translational) hardening with corresponding parameters of elasticity and plasticity. The model takes into account kinematics of spatial transformation of the shaping equipment as well as the time-variable conditions of its contact interaction with the blank.     

Investigation of power gas turbine drives on the basis of mathematical models

A method for investigation of power gas turbine drives on the basis of mathematical models that makes it possible to enhance an information content and precision of existing techniques of power audit is proposed.     

Polar caps and auroral zones under idealized axisymmetric magnetic fields

The geomagnetic field, modified by the solar wind, determines the shape, area and location of polar caps and auroral zones, among other magnetosphere and upper atmosphere characteristics. Since the field varies greatly with time it is of interest to analyze polar caps and auroral zones variations linked to magnetic field variations of intensity and pattern. Polar caps and auroral zones locations and areas for various single harmonic axial field configurations are obtained analytically assuming a simple magnetopause model. As the axial degree n increases, the polar caps and auroral zones total number, given by n + 1 and 2n respectively, also increase. However, their total areas decrease from a larger value in the case of an axial dipole to a minimum for an axial octupole (n = 3), and then increase for increasing degrees. The increasing rate is much higher in the auroral zones case to the point that it exceeds the dipolar value at n = 5 while in the polar caps case this occurs at n = 8. The absolute latitudes of the auroral zones and polar caps that reside around the geographical poles increase with axial degree. Our results represent an end-member case of the evolution of auroral zones and polar caps during polarity reversals if the transition involves axial dipole energy cascade to higher axial degrees. Evidence for such an energy transfer is found in the historical record of the geomagnetic secular variation.     

A Method for Designing the Helicopter Skid Landing Gear by a Criterion of Landing Impact Energy Absorption

This paper presents the results of calculating the energy criterion being proposed by an example of two types of skid landing gear for a multipurpose helicopter of transport category.