Видання зареєстровані авторами шляхом самоархівування
Permanent URI for this communityhttps://devessuir.sumdu.edu.ua/handle/123456789/1
Browse
3 results
Search Results
Item Influence of the degree of off-design of the traction nozzle of a jet reaction turbine on its efficiency(IOP Publishing Ltd, 2021) Ванєєв, Сергій Михайлович; Vanieiev, Serhii Mykhailovych; Родимченко, Тетяна Сергіївна; Rodymchenko, Tetiana Serhiivna; Мелейчук, Станіслав Станіславович; Meleichuk, Stanislav Stanislavovych; Бага, Вадим Миколайович; Baha, Vadym Mykolaiovych; Bolotnikova, О.At the present stage of social development, the need for rational use of energy resources of the planet is particularly acute. Most countries have already faced the problem of the energy crisis. An appropriate way to solve this problem is the utilization of secondary energy resources. With the help of turbine generators, it is possible to reduce the pressure and utilize the potential energy of excess pressure of gas or vapours to produce electricity. Such units can be created based on a jet reaction turbine. The study aims to assess the impact of the degree of off-design of the traction nozzle on the efficiency of the jet reactive turbine. The analysis of the factors influencing the efficiency of the jet reaction turbine is carried out in the work. The obtained efficiency rate for the jet reactive turbine depending on the given dimensionless velocity of λout.t at the inlet pressure of the inlet nozzle of 2, 4, 6 and 10 MPa in the design mode (at the degree of off-design of S = 1) and in the off-design modes of operation ( S> 1). Graphical dependencies of the jet reaction turbine efficiency rate on the given circular velocity of the impeller are constructed (U ̅ = 0… 0.7). The research shows that with increasing pressure at the inlet to the inlet nozzle, the efficiency rate of the turbine increases, and the optimum of the efficiency rate is shifted towards the increase of the given circular velocity of the impeller, both in the design and off-design operating modes. It is found that the greatest value of the efficiency rate is acquired at the design mode of operation of the traction nozzle, i.e. at S = 1.Item Results of the study of a turbogenerator with a peripheral-side channel in non-dimensional and criterial complexes(MM Science Journal, 2022) Ванєєв, Сергій Михайлович; Ванеев, Сергей Михайлович; Vanieiev, Serhii Mykhailovych; Martsynkovskyy, V.; Hatala, M.; Miroshnichenko, D.; Bilyk, Y.; Смоленко, Дмитро Віталійович; Смоленко, Дмитрий Витальевич; Smolenko, Dmytro Vitaliiovych; Лазаренко, А.; Botko, F.Dimensionless and criterial complexes are successfully used in many technical fields. They play an important role in research and design. There are a large number of dimensionless and criterial complexes, which have their advantages and are chosen depending on the topic and specific objectives of the study. The article considers dimensionless and criterial complexes most often used in studies of turbomachines, in particular vortex expansion machines - relative internal (isoentropic) efficiency, degree of pressure drop, adjusted wheel speed, speed coefficient, adjusted diameter, flow factor and coefficient. The authors processed the data of the experimental study of the turbogenerator with a peripheralside channel and presented them in the form of graphical dependences using these complexes. The improvement of these energy-saving turbogenerators is important because they are used to generate electricity from excess gas pressure, are considered environmentally friendly and are needed for the development of distributed energy. Vortex expansion machines with a peripheral-lateral channel are also poorly understood, so the topic is relevant. In this study, their area of use was determined and reflected in the ns - Ds diagram among radial and other vortex expansion turbomachines to facilitate their comparison and design.Item Numerical Simulation of Gas Flow Passing through Slots of Various Shapes in Labyrinth Seals(MDPI, 2022) Бага, Вадим Миколайович; Бага, Вадим Николаевич; Baha, Vadym Mykolaiovych; Lishchenko, N.; Ванєєв, Сергій Михайлович; Ванеев, Сергей Михайлович; Vanieiev, Serhii Mykhailovych; Mizakova, J.; Родимченко, Тетяна Сергіївна; Родимченко, Татьяна Сергеевна; Rodymchenko, Tetiana Serhiivna; Pitel, J.Labyrinth seals are widely used in centrifugal compressors, turbines, and many other pneumatic systems due to their simplicity of design, reliability, and low cost. The calculation scheme for the movement of the working medium in a labyrinth seal is constructed by analogy with the movement of the working medium through holes with a sharp edge. Annular and flat slots, holes, and such a factor as the shaft rotation with a calculated sector of 3 degrees were studied. The purpose of the study is to determine the flow coefficient when the working medium flows through slots of various shapes. To achieve this purpose, modeling of the working medium flow in the FlowVision software was performed. The mass flow and flow coefficients are determined for the studied slot shapes. The convergence of the calculation results was determined by comparing the values of the mass flow rate at the inlet and outlet of the slot. Differences in visualizations of the flow for the studied variants of slots were established. The resulting difference should be taken into account in practical calculations of the working medium mass flow through the slot using a conditional flow rate factor which is determined by the slot design.