On certain approaches to the control methods development for the precipitation formation processes in convective clouds

The article aims at searching for the optimal way of emission of ice nucleating agent in convective cloud in order to prevent ‎formation of harmful hail by analyzing simulations of this process within a numerical model ‎of cloud‎. The state of the physics of clouds and active influences on them is discussed. It is noted that at the present time studies of the regularities of the formation and development of clouds as a whole begin taking into account their systemic properties. The main directions of research at the next stage of its development are discussed. The features of the existing methods of active action on convective clouds are noted, the main tasks encountered in the development of methods for controlling sedimentation in convective clouds by introducing reagents are formulated. It is noted that research on the development of methods for active influence on clouds should be conducted on the basis of new and more effective approaches, which should be based on the extensive use of mathematical modeling. Some approaches to solving this problem are discussed. According to the authors, the most promising of them are approaches based on the theory of optimal control and bifurcation theory. Some results of numerical modeling of the active effect on convective clouds are given

ВЛИЯНИЕ ГИБРИДНОГО НАПОЛНЕНИЯ КОРОТКИМ СТЕКЛОВОЛОКНОМ И ТЕРМОРАСШИРЕННЫМ ГРАФИТОМ НА СТРУКТУРУ И СВОЙСТВА ПОЛИЭТИЛЕНТЕРЕФТАЛАТА

The effect of short glass fibers (GFs) and thermally expanded graphite (TEG), added to polyethyleneterephtalate (PET), on mechanical, including dynamical mechanical, and rheological properties, as well as the structural features of the produced composites is studied. Compounding with the PET melt is realized by reactive extrusion using a co-rotating twin screw extruder-reactor with L / D = 40. Analyzed composites contained from 15 to 60 wt. % of GFs, and the TEG concentration was 0.5 and 3.0 wt. It is found that hybrid filling of PET results in a synergetic increase of the tensile modulus of the composites reaching the values more than 22 GPa, as well as that of the dynamic shear modulus in a wide temperature range. Adding TEG into PET/GF composites increases the degree of binder crystallinity. An effect of an anomalous decrease in the intrinsic viscosity of PET solutions and an increase in the melt flow index of the melt composites observed at higher GF concentrations is attributed to a deeper degradation of polymer. Исследовано влияние добавок коротких стеклянных волокон (СВ) и терморасширенного графита (ТРГ), вводимых в полиэтилентерефталат (ПЭТ), на механические, в том числе динамические механические, и реологические свойства, а также особенности структуры получаемых композитов. Компаундирование материалов осуществляли смешением в расплаве ПЭТ методом реакционной экструзии при использовании двухшнекового реактора-смесителя с односторонним вращением шнеков и L / D = 40. Исследуемые композиты содержали от 15 до 60 мас. % СВ, а концентрация ТРГ составляла 0,5 и 3,0 мас. %. Показано, что при гибридном наполнении ПЭТ наблюдается синергическое повышение модуля упругости композитов, предельные значения которого превышают 22 ГПа, а также динамического модуля сдвига в широком интервале температур. При введении ТРГ в композиты ПЭТ/СВ повышается кристалличность связующего. Обнаружен эффект аномального снижения характеристической вязкости растворов ПЭТ и повышения текучести расплава композитов при повышенной >30 мас. % концентрации наполнителей, что обусловлено углублением деструкции макромолекул.