With an increase in the power/weight ratio of vehicles in cities and towns, the thermal loads of many functional units increase significantly. This requires the organization of the removal of excess heat into the environment, since the violation of the proper thermal regime in individual functional units prevents the realization of the potential operational properties of the entire vehicle up to failure. At the same time, the variety of operating conditions for vehicles, causing a change in a wide range of factors of the working environment, especially road and climatic ones, creates a difficult, both in practical and theoretical terms, problem of ensuring the required thermal regime for functional units. In this regard, the paper presents a consistent development of the theory of hydrothermodynamic properties of functional units based on the principles of constructing the operational properties of vehicles. The problems determining the further search and scientific substantiation of meters and indicators for assessing the efficiency of cooling systems, as well as the development of methods, tools and equipment for calculating and studying these systems are considered. At the same time, the work presents the improvement of the working process and designs of gas engines of tractors aimed at increasing reliability through the use of new production technologies. In conclusion, the definition of scientifically grounded methods and practical solutions for improving the performance of cooling systems is given, which has an important scientific and economic significance for increasing the operational properties of agricultural tractors, substantiating the current importance.
Global car manufacturers wish to increase the number of manufactured products, reduce their cost and labor input. The choice of research areas, design and technological developments in radiator construction is an extremely important and urgent task, due to the mass production of radiators for tractors and automobiles on the one hand, and the favorable development prospects of these interrelated industries, on the other. (Research purpose) To substantiate theoretically and experimentally the use of a combined cooling system containing both aluminum and polymeric water radiators and similarly liquid-oil heat exchangers based on the four principles listed above on automobiles and tractors. (Materials and methods) The authors performed bench tests using a special wind tunnel to study the thermal and aerodynamic characteristics of a prototype tractor radiator with a polyurethane core. After reaching the steady-state operating mode of the installation, the experimental values were determined for the control and measuring instruments. (Results and discussion) The authors carried out measurements of all parameters of both coolants in series at each steady-state operating mode of the bench. They obtained the main indicators dependences (reduced heat transfer, aerodynamic and hydraulic drag) of the heat exchanger, close to the operating conditions of the vehicles. (Conclusions) A prototype MTZ-80 radiator with a polyurethane core has great prospects as a future alternative radiator. An increase by 10-15 percent in the radiator heat transfer is possible by using aluminum fi ns on the surface of the polyurethane plate. A 15-20 percent reduction in hydrodynamic resistance is achieved by increasing the diameter of the capillary throughput in a polyurethane plate and the number of plates themselves in the radiator cell.
Министерство образования и науки Российской Федерации Федеральное государственное бюджетное образовательное учреждение высшего профессионального образования «Тамбовский государственный технический университет» Н.В. ПЕНЬШИН МЕТОДОЛОГИЯ ОБЕСПЕЧЕНИЯ БЕЗОПАСНОСТИ ДОРОЖНОГО ДВИЖЕНИЯ НА АВТОМОБИЛЬНОМ ТРАНСПОРТЕ Допущено УМО вузов Российской Федерации по образованию в области транспортных машин и транспортно-технологических комплексов в качестве учебного пособия для студентов вузов, обучающихся по направлению подготовки бакалавров «Технология транспортных процессов» (профиль подготовки «Организация и безопасность движения») Тамбов Издательство ФГБОУ ВПО «ТГТУ» 2013
This article is devoted to the analysis of problems associated with the state of the musculoskeletal system in patients who survived malignant neoplasms in childhood. The main diseases and pathological conditions that can develop in this population are considered. The risks of pathological changes in the musculoskeletal system, treatment and prevention are described. The issues of long-term consequences after limb amputation, organ-preserving operations, osteonecrosis, scoliosis, osteoporosis are separately analyzed.
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