69439 2658-5553 19 4 19 2021 1-60

REV RUS 1901-1901 0000-0001-5973-7419 Peter the Great St. Petersburg Polytechnic University Taheri Fard Ali Reza alireza_taherifard@yahoo.com

St. Petersburg, Russian Federation

Pipe Erosion Under Multiphase Flow. A Review Sand is often produced simultaneously with oil, and gas, which causes a significant issue in the petroleum industry. Therefore, sand production in gas and oil extraction needs to be studied thoroughly as it can cause many problems. Three problems arise among all: reducing pressure, pipe obstruction, and erosion. The second is a complicated, impersonal process in which material is eliminated from the pipe by the replicated effect of sand particles. Consequently, the pipe undergoes an erosion process. Erosion in pipes can lead to failures in pipelines, economic damage, and environmental problems. Hence, it is crucial to identify the parameters which determine erosion events as well as modeling them. This article provides an overview of the essential factors causing erosion and an explanation of the current erosion equations. It also describes experimental, and mechanical models of pipe erosion prediction. Moreover, it explains the modeling of fluid erosion dynamics as a comprehensive fragmentation study method. Ultimately, potential limits and shortcomings regarding erosion are demonstrated. 10.57728/ALF.19.1 69 Erosion Sand particle Turbulent flow Boundary layer flow Multiphase flow Fluid mechanic Erosion modeling CFD modeling Mass transfer https://alfabuild.spbstu.ru/article/2021.19.1/

REV RUS 1902-1902 56352359500 0000-0002-5156-7352 Volgograd State Technical University Korniyenko Sergey Valeryevich svkorn2009@yandex.ru

Volgograd, Russian Federation

Progressive Trend in Adaptive Façade System Technology. A Review During the last decades, a great number of innovative building envelope materials, products, and façade systems have been developed. The majority of these progressive technologies promise significant improvements in energy efficiency and occupant’s comfort. However, it remains a challenge to assess the performance of such façades, leading to difficulties for efficient design, construction, and maintenance. As a consequence, the market adoption of adaptive façades is not realizing its full potential, resulting in missed opportunities for energy savings and improved occupant satisfaction. In this research, the main trends of adaptive façade development were investigated, with particular emphasis on their performance assessment. The literature review identifies and describes a knowledge gap in the assessment and systematization of adaptive façade systems. Our research methodology combines mixed methods of research involving collecting, analyzing, and integrating quantitative and qualitative research. For the first time, the main types of adaptive façade systems were systematized and ordered. Based on the analysis of consumer properties of these façades, the main trends were revealed. New technologies including adaptive building skins meet changing environmental conditions, host multiple functions and offer decentralized controls for occupants. They serve as strategies for improved comfort and reduced building energy needs. Finally, we can assume that adaptive façades technology is not ready enough to cross barriers today, however, the technology remains a promising technology that can get better in near future. 10.57728/ALF.19.2 69 Adaptive façade Building envelope Building skin Energy efficiency Environment Biomimetics Trends https://alfabuild.spbstu.ru/article/2021.19.2/

RAR RUS 1903-1903 H-9967-2013 16412815600 0000-0002-8588-3871 Moscow Power Engineering Institute Kirsanov Mikhail Nikolaevich mpei2004@yandex.ru

Moscow, Russian Federation

Deformations of a Triangular Trussed Rafter With an Arbitrary Number of Panels: An Analytical Solution The object of the study is a planar, statically determinate lattice truss on two supports. The upper belt of the structure has a triangular outline. The task is to obtain formulas for the dependence of the deflection and displacement of the movable support on the number of panels. Method. To obtain the deflection value, the Maxwell-Mohr formula is used. The forces in the rods are found by cutting out nodes from the solution of a system of linear equations. All transformations and calculations are performed symbolically in the Maple computer mathematics system. The generalization of a series of particular solutions obtained for trusses with a sequentially increasing number of panels to an arbitrary case is performed by induction using Maple operators. Results. Three types of loads are considered, including lateral wind load. The calculated formulas obtained contain the coefficients in the form of polynomials in the number of panels and, in comparison with similar solutions for other structures, have a very compact form. The distribution of forces over the elements of the lattice is given. Formulas are derived for some of the rods that are most critical to the loss of strength or stability.  10.57728/ALF.19.3 69 Trussed Rafter Analytical Solution Deflection Maple Induction https://alfabuild.spbstu.ru/article/2021.19.3/

RAR RUS 1904-1904 0000-0002-4107-2452 Belarusian-Russian University Moskalkova Yuliya Georgievna julia43@tut.by

Mira Ave, 43, 212000, Mogilev, Republic of Belarus

0000-0001-8854-5408 Belarusian-Russian University Rzhevutskaya Valeria Andreevna valeriarzhevuckaya@gmail.com

Mira Ave, 43, 212000, Mogilev, Republic of Belarus

Compressive Strength of Expanded Clay Fiber-Reinforced Concrete The object of research is expanded clay fiber-reinforced concrete based on polypropylene fiber. Dispersed reinforcement with polymer fiber is one of the priority directions for modifying lightweight concrete, in particular, expanded clay concrete. There is no consensus among researchers on the effect of the reinforcement with polypropylene fiber on the strength characteristics of lightweight fiber-reinforced concrete. The influence of the cross-sectional dimensions of the specimens on the values of the compressive cube strength of expanded clay fiber-reinforced concrete has not been studied. Method. The article presents the preliminary results of experimental study of the influence on the compressive cube strength of expanded clay fiber-reinforced concrete by the following factors: the reinforcing polypropylene fiber content (0.12 %, 0.24 %, and 0.36 % by concrete volume), the edge size of the testing cubes (100 mm or 150 mm). Results. The obtained empirical data and analytical review allowed to state, that it is not ensured to obtain correct values of compressive cube strength if cube specimens are with an edge of 100 mm regardless of the reinforcement percentage. Therefore, it is recommended to test cubes with an edge of 150 mm or more. Conclusions. The characteristic values of the strength of expanded clay concrete and expanded clay fiber-reinforced concrete can be obtained on the basis of the test results of both cylinders and cubes. The mean values of the cylindrical and cube strength are comparable.  10.57728/ALF.19.4 69 Lightweight concrete Expanded clay concrete Dispersed reinforcement Polypropylene fiber Compressive cylinder strength Compressive strain Stress-strain diagram https://alfabuild.spbstu.ru/article/2021.19.4/

REV RUS 1905-1905 AAT-4496-2020 57212563392 0000-0002-9980-5356 Peter the Great St. Petersburg Polytechnic University Petrushchenkov Valery Alexandrovich pva38@mail.ru

Russia, 195251, St.Petersburg, Polytechnicheskaya, 29

The history of the creation of the first Combined Heat and Power Plant in Russia The purpose of the work is to describe the history of the Leningrad State Power Plant-3 (further SPP-3), on the basis of which the first Combined Heat and Power Plant (further CHPP) in Russia was created in 1924. The long period from the emergence of the station of the Belgian Anonymous Society on the Fontanka River embankment to its transfer to the operation mode of the Thermal power plant is considered. The biography of the main creator of the first CHPP - Ginter Leonti Leontievich is given. The contribution of Professor Dmitriev Vladimir Vladimirovich and other participants to its creation is described. The schematic and design features of the heat supply systems of the first three thermal consumers of SPP-3 are reviewed: heating systems of a residential building at 96 Fontanka, hot water systems of the Egorievsk baths, heating systems, ventilation and hot water supply of the Obukhov hospital. The stages of the reconstruction of SPP-3 with the transition to the mode of joint production of electric and thermal energy are given. The priority starts date of the centralized heat supply system based on SPP-3 has been clarified. The role of SPP-3 in the spread of heating in the country has been assessed. 10.34910/ALF.19.5 69 Heating Heating line Types of heat load Degraded vacuum Heating point circuit Water coolant https://alfabuild.spbstu.ru/article/2021.19.5/ 1905_A.pdf