I. A. Bykadorov, Yu. N. Ismaiylova, M. V. Pudova, S. E. Khruschev
Siberian Institute of Management, Novosibirsk, Russian Federation
Keywords: interregional trade, transport costs of "iceberg types", social optimality, elasticity
We study the model of interregional trade under monopolistic competition of producers. We obtain a local comparative statics of symmetric social optimality with respect to transport costs. Particular attention is paid to situations of free trade and autarky. For the case of two regions, counterintuitive results we obtain that (1) with low transport costs in one of the regions, public welfare can either increase or decrease; (2) when transport costs are high, trade liberalization worsens public welfare in one region and improves it in another.
Responsible investment is a trend in the development of the world economy. Russia’s lagging behind the trend can lead to negative effects on the economy. The article examines the formation of responsible investment as an economic institution. An institutional-evolutionary approach based on the principles of variability, selection and heredity of conditions, rules, norms and restrictions of economic activity is applied. It is shown that the institutionalization of responsible investment can be the result of not only external influence on economic agents, but also the result of their independent activity. In this regard, the regulator should pay attention to the problem of information asymmetry, which prevents the spread of responsible investment in the activities of economic agents and its subsequent institutionalization.
S. Z. Faronova
Bashkir State University, Ufa, Russian Federation
Keywords: digitalization, industry, directions of development, strategic task, digital, information platform
The purpose of the article is to consider the directions of digital transformation of housing and communal services as one of the most problematic sectors of the economy. The main state programs and strategies aimed at the digital transformation of the industry are highlighted. Real examples are presented in the priority areas of digital transformation of housing and communal services. We considered possible obstacles to the introduction of digitalization and identified additional initiatives regarding the introduction of digital technologies on the example of the region of Russia - the Republic of Bashkortostan.
Results of numerical and experimental investigations of the efficiency of distributed air blowing through a perforated region of the surface of an axisymmetric body of revolution in an essentially incompressible flow with the Reynolds number ReL = 4,24·106 are reported. The blowing factor Cb is varied in the interval 0-0.00885. The Reynolds number Re** based on the momentum thickness δ** ahead of the perforated region is 5600. As the streamwise coordinate х increases, stable reduction of local friction is observed up to the distance of 600 δ** from the blowing region; the maximum value of local friction reaches 56.5% directly in the region of blowing with the maximum intensity. It is found that spontaneous blowing, which occurs due to the natural difference between the barometric and static pressures in the wind tunnel test section, can also ensure reduction of the skin friction coefficient whose value in the above-noted flow region in the main operation regime is 28.5%. Specific features of the flow around the body of revolution in the case of a rough perforated surface is analyzed through numerical simulations, and it is demonstrated that it is necessary and important to take into account this factor accompanying the blowing process.
The results of an analytical study of unsteady heat transfer in the vicinity of a stagnation point of an axisymmetric impinging liquid jet are presented. A self-similar solution is obtained, which allows the analysis of heat transfer behavior as a function of the Reynolds number, distance from the nozzle to the surface, and characteristic time. The behavior of the Nusselt number for the solution in asymptotically limiting cases is shown: the Froude number Fr >> 1 (small distances from the nozzle to the barrier) and Fr << 1 (large distances). It is noted that the effect of the Froude number can be quite significant and should be taken into account when predicting heat transfer. Significant intensification of heat transfer is shown for a pulsed impinging jet at short pulse durations.
P. Eiamsaard1, K. Wongcharee2, K. Kunnarak2, Kumar Manoj3, S. Eiamsaard2, M. Pimsarn4
a:2:{s:4:"TEXT";s:283:"1Rajabhat Rajanagarindra University, Chachoengsao, Thailand 2Mahanakorn University of Technology, Bangkok, Thailand 3DIT University, Dehradun Uttarakhand, India 4King Mongkut’s Institute of Technology Ladkrabang, Bangkok, Thailand";s:4:"TYPE";s:4:"html";}
Keywords: heat exchanger, heat transfer visualization, swirling impinging jet, triple spiral-corrugated nozzle, twisted-tape
Thermal visualization using a thermochromic liquid crystal sheet was performed to investigate and compare heat transfer behavior of a swirling impinging jet emerging from a triple spiral-corrugated nozzle with a twisted tape ( SIJ with TT ), a SIJ issuing through a triple spiral-corrugated nozzle, and a typical/conventional impinging jet ( CIJ ) emerging from a smooth straight circular nozzle. The experimental results showed that the stronger jet recirculation close to the wall due to the swirl flow created by triple spiral-corrugated nozzle and twisted tape inserts ( SIJ with TT ) support in reducing the value of Nusselt number between the stagnation region and surroundings. For the SIJ with TT , the average Nusselt number (Nu) performed by the jets with L/dH shows that the magnitude of the heat transfer coefficient was significantly enhanced with increasing twist ratios. The maximal value of the Nusselt the SIJ with TT was obtained at the lowest twist ratio ( y/W = 2.0). This was up to 5.7 % and 35.5 % higher than those of the SIJ with TT at y/W = 4.0, and the CIJ, respectively.
A.B. Kruglov, V.I. Rachkov, I.G. Merinov, V.S. Kharitonov, L.P. Paredes
a:2:{s:4:"TEXT";s:59:"National Research Nuclear University “MEPhI”, Moscow,Russia";s:4:"TYPE";s:4:"text";}
Keywords: pulse heating method, thermal conductivity coefficient of lead, impurities in lead, thermal resistance of contact of lead melt and steel
The article presents the results of measuring the coefficient of thermal conductivity of lead in the temperature range of 350-1000 °C using the pulse heating method. The methodology of processing experimental data is described. The estimates of the experimental data error are given. The difference in the content of impurities in the lead samples is shown to have an in significant effect on the thermal conductivity coefficient of the lead melt. The deviation of the experimental data on the thermal conductivity of lead from the proposed interpolating dependence does not exceed ±2 %. The obtained data are compared with the known recommended dependences for calculating the thermal conductivity coefficient of lead.
A comprehensive study of the thermophysical properties of an ultralight eutectic Mg-Li alloy (with a lithium content of 23 at.%), promising for use in the aerospace industry has been carried out. New reliable experimental data have been obtained for thermal conductivity, thermal diffusivity, specific heat capacity, density, linear thermal expansion coefficient and relative elongation of the alloy in the temperature range of 300 - 759 ÷781 K. The obtained results have been compared with well-known literature data on thermal conductivity and thermal expansion for Mg-Li system alloys. Approximation equations and a table of reference data of the studied properties are presented. The relative density change during melting of eutectic has been determined.
S.D. Sleptsov1, N.A. Savvinova2 1Kutateladze Institute of Thermophysics SB RAS Novosibirsk, Novosibirsk, Russia 2North-Eastern Federal University, Yakutsk, Russia
Keywords: ice, melting, Stefan problem, anisotropic scattering, selectivity, substrate
Numerical calculation of the influence of various types of opaque substrates on ice melting was carried out using mathematical modeling methods. It is shown that while maintaining a constant low temperature of the left boundary of the heat-conducting substrate, ice melting does not depend on its thermophysical properties. The threshold value of thermophysical properties, below which the dependence on the substrate must be taken into account, is found.
4 August, 2007 is the 75th anniversary of the well known scientist, scientific administrator and head of scientific school of Tymen Division of Khristianovich Institute of Theoretical and Applied Mechanics of the Siberian Branch of the Russian Academy of Sciences, Doctor of Physical and Mathematical Sciences, Professor Amir A. Gubaidullin.
