Nozzle Apparatus Research Articles

Expansion of the range of permissible loads of a marine four-stroke diesel engine when using an adjustable turbocharger nozzle apparatus

The paper analyses the influence of the adjustable turbocharger nozzle apparatus on the parameters and criteria determining the thermal and mechanical stress of the main marine four-stroke diesel engine. The methodology of construction of limiting characteristics of mechanical and thermal stress using approximation dependences of parameters and criteria obtained by calculation-theoretical method is developed. The main parameters limiting the range of maximum permissible diesel engine loads on mechanical and thermal stress in the initial variant and in the variant with adjustable nozzle apparatus are revealed. It is established that the increase in the angle of rotation of blades of the adjustable nozzle apparatus up to the maximum permissible value causes a decrease in the parameters of thermal stress, as a result of which the zone of maximum permissible modes of operation of the diesel engine expands. At the same time, the parameters and criteria determining the mechanical stress of the diesel engine increase, but the reduction of the zone of maximum permissible loads on mechanical stress does not reduce the range of maximum permissible loads established by changing the thermal stress parameters.

Searching for Possible Design Solutions to Extend the Service Life of the HPC of a Powerful NPP Turbine after Damage to the Rotor Blades

The aim of this research was to analyze and evaluate possible design solutions for the flow path of the high-pressure cylinder (HPC) of the K-1000-60/3000 turbine and the possibility of their short-term implementation in a nuclear power plant after an accidental destruction of the working blades of the last stage of the HPC in conditions of the shortage of generating capacities and a tense operation state of the power system. To achieve the set goals, an appropriate methodology was developed; a mathematical model of thermo-and gas dynamic processes in the flow path of a steam turbine was improved. To make appropriate decisions on changing the design of the turbine, the necessary computational studies of the HPC of the K-1000-60/3000 turbine of the designed structure, the structure without rotor blades of the 5th stage and the structure with four first stages (without the fifth stage) were carried out for both turbine steam flows. The results of the study of thermo- and gas dynamic parameters of the flow showed the presence of differences in the operating conditions of all turbine stages, and these are the most significant for the 4th and 5th stages. A significant redistribution of thermal differences in the stages, and a decrease in the internal power of the HPC of the turbine by 35.5 MW and 6.6 MW respectively, as well as a decrease in their internal efficiency by 11.8 % and 2.1 %, respectively, were noted. Taking into account all the aspects related to the operation of the power unit, the most successful solution for the rapid resumption of operation of a powerful turbine plant used by a nuclear power plant after an accidental damage to the working blades is a HPC design without the working blades of the fifth stage. It is planned to carry out additional studies of the HPC design by replacing the nozzle apparatus of the fifth stage with an appropriate simulator.

Влияния угла наклона сопел на коэффициент скорости центростремительной турбины с частичным облопачиванием рабочего колеса

The paper considers a numerical experiment with three groups of low-consuming inflow turbines with partial blading of the runner. Geometrical models of the turbine stages with partial blading of the runner at different angles of the nozzle inclination have been developed. The inflow turbine stages with partial blading of the runner are investigated. The efficiency and speed coefficient of the inflow turbine nozzles are calculated. There has been carried out numerical modeling of the working fluid flow by using the computational gas dynamics elements. Pick values of the nozzle apparatus velocity coefficient and the turbine stage efficiency are defined. Geometric models of the turbine stages with different nozzle inclination angles are developed, the boundary conditions of the experiment are determined, and the experiment results are analyzed and shown. There are given the dependence graphs of the nozzle velocity coefficient and the efficiency of a low-consuming inflow turbine stage. Comparative analysis of the nozzle velocity coefficient and the efficiency of three turbine stages with different inclination angles of the nozzles in the nozzle apparatus has been carried out. Conclusions are drawn about further procedures on improving the flow part of the runner to increase the efficiency of the stage.

ОСОБЕННОСТИ ПРИМЕНЕНИЯ МНОГОКООРДИНАТНЫХ ШЛИФОВАЛЬНЫХ СТАНКОВ С ЧПУ ДЛЯ ПОВЫШЕНИЯ ПРОИЗВОДИТЕЛЬНОСТИ, КАЧЕСТВА И ТОЧНОСТИ ОБРАБОТКИ ДЕТАЛЕЙ И УЗЛОВ АВИАЦИОННЫХ ГАЗОТУРБИННЫХ ДВИГАТЕЛЕЙ

The paper is aimed at improving the productivity, quality and accuracy of manufacturing gas turbine engine parts and assemblies for the modern growing passenger aviation transport based on the use of technical capabilities of modern multiaxis CNC grinding machining centers. The paper shows the results of successful application of a five-axis CNC grinding machining center MFP-050.65.65 made by Magerle (Switzerland), which allows reducing by five times the number of operations, universal machines, special devices and cutting tools by increasing the number of machined surfaces for one set of nozzle blades of an aviation gas turbine engine. Simultaneously with a significant increase in the productivity of machining various multidirectional surfaces of the nozzle blades due to the use of new highly porous grinding wheels and rational modes of deep grinding, a higher burn-free quality of the ground surfaces is ensured and an important task is solved to increase the accuracy of the flow sections of the turbine nozzle apparatus with the combined use of CNC system and special software for correcting errors of part casting surfaces during their installation, turning and deep grinding of the base surfaces. The developed new technology of nozzle blades machining was introduced for the first time in the Russian Federation at the Aviadvigatel enterprise for manufacturing nozzle blades of modern newly produced gas turbine engines.

Experimental and theoretical study of the low-temperature kinetics of the reaction of CN with CH2O and implications for interstellar environments.

Rate coefficients for the reaction of CN with CH2O were measured for the first time below room temperature in the range 32-103 K using a pulsed Laval nozzle apparatus together with the Pulsed Laser Photolysis-Laser-Induced Fluorescence technique. The rate coefficients exhibited a strong negative temperature dependence, reaching (4.62 ± 0.84) × 10-11 cm3 molecule-1 s-1 at 32 K, and no pressure dependence was observed at 70 K. The potential energy surface (PES) of the CN + CH2O reaction was calculated at the CCSD(T)/aug-cc-pVTZ//M06-2X/aug-cc-pVTZ level of theory, with the lowest energy channel to reaction characterized by the formation of a weakly-bound van der Waals complex, bound by 13.3 kJ mol-1, prior to two transition states with energies of -0.62 and 3.97 kJ mol-1, leading to the products HCN + HCO or HNC + HCO, respectively. For the formation of formyl cyanide, HCOCN, a large activation barrier of 32.9 kJ mol-1 was calculated. Reaction rate theory calculations were performed with the MESMER (Master Equation Solver for Multi Energy well Reactions) package on this PES to calculate rate coefficients. While this ab initio description provided good agreement with the low-temperature rate coefficients, it was not capable of describing the high-temperature experimental rate coefficients from the literature. However, increasing the energies and imaginary frequencies of both transition states allowed MESMER simulations of the rate coefficients to be in good agreement with data spanning 32-769 K. The mechanism for the reaction is the formation of a weakly-bound complex followed by quantum mechanical tunnelling through the small barrier to form HCN + HCO products. MESMER calculations showed that channel generating HNC is not important. MESMER simulated the rate coefficients from 4-1000 K which were used to recommend best-fit modified Arrhenius expressions for use in astrochemical modelling. The UMIST Rate12 (UDfa) model yielded no significant changes in the abundances of HCN, HNC, and HCO for a variety of environments upon inclusion of rate coefficients reported here. The main implication from this study is that the title reaction is not a primary formation route to the interstellar molecule formyl cyanide, HCOCN, as currently implemented in the KIDA astrochemical model.

Design optimization of the suspension unit of the liner in the combustion chamber housing

The design of the suspension unit of the flame tube in the housing of the annular combustion chamber of a ground-based gas turbine installation of a gas pumping unit is given for placing it in a device for fixing the flame tube in the combustion chamber housing, where automatic clearance selection is required arising between the contacting surfaces of the docking nodes of the combustion chamber and the nozzle apparatus of the turbine, when the combustion chamber is operating as part of the engine. The proposed design of the suspension unit of the flame tube in the annular combustion chamber housing makes it possible to increase the reliability and resource of the combustion chamber and, in general, the entire ground-based gas turbine installation by eliminating the jamming of the split rings in the cups of the suspension units and the misalignment of the pushers relative to the suspension units and split support rings.

Процес дроселювання в соплових апаратах з поворотними діафрагмами

In the process of developing a method for numerically investigating a plane flow around a nozzle array with a rotary diaphragm, calculations were performed for various degrees of opening of the rotary diaphragm δ and pressure drops π on the array. The article presents some results of a numerical study of the flow in the nozzle channel at the degree of opening of the rotary diaphragm δ = (1…0.15). Modeling and calculations of the flow of the working fluid were performed using the Fluent software package. The construction of computational areas, limited by one inter-blade channel, for a different degree of opening of the diaphragm of the nozzle apparatus has been carried out. The grids for the computational domains were constructed. Calculations were carried out for δ = (1…0.15) and for various degrees of pressure drop across the grate. Because of the performed calculations, flow patterns in the interblade channel and behind it, and the distribution of kinetic energy loss coefficients along the grating front at various degrees of aperture opening at the nozzle inlet, were obtained. Based on the results of the work carried out, the following conclusions can be drawn: the operation of a nozzle array with a rotary diaphragm at different degrees of opening of the rotary diaphragm δ and pressure drops π on the grate can be divided in the range of opening steps δ = (1…0.77) as operation in the nozzle mode, and in the range δ = (0.77…0.15) as in throttle mode; when the angle of attack changes, the values of the kinetic energy loss coefficients increase significantly (up to 25 %) only for π = 0.7 and δ = 1; at π = 0.3 and δ = 1, the coefficient increases slightly (up to 0.5 %); at π = 0.7; 0.3 and δ = 0.3, the coefficient increases to 5 %, while the coefficient ζі changes less relative to the coefficient ζ90 at the calculated angle of attack α0 = 90 grids). The results obtained in this work will be used to develop a technique for numerically investigating the spatial flow around nozzle arrays with rotary diaphragms.

Исследование эффективности различных систем охлаждения перспективных газотурбинных двигателей

The paper focuses on foreign and Russian aviation bypass turbojets with an afterburner, studies the design of their turbine cooling systems, and introduces the research findings. For computational research and comparative analysis, we used Russian and foreign samples of advanced bypass turbojets with an afterburner with the most optimal technical characteristics, made calculations of the gas-dynamic parameters of their cooling systems in four critical jet operating modes. In this paper, we introduce the results of hydraulic calculations of various schemes for supplying cooling air to the nozzle and working blades of a high-pressure turbine. Relying on the results of the calculation, we comparatively analyzed the foreign and Russian cooling systems design, in terms of power indicators and efficiency of a gas turbine jet. To do this, we used the following parameters: cooling air bleeding value at maximum jet speed and cruising mode, value of cooling air leakage through the axial gaps into the flow path, the change in the cooling air bleeding value as a percentage of the flow rate through the high-pressure compressor when switching from maximum to cruising mode, i.e. adaptability of the cooling system, the temperature of the cooling air at the point of supply to the cooling cavities of the blade of the nozzle apparatus or the working blade.

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The subject of the research is modern marine turbomachines which differ in many types, designs, purposes, materials and working bodies. It is noted that this diversity is guaranteed by the use of modern computer technologies from the stage of preliminary preparation of production to the release of final products. The design stage of turbine units taking into account the external characteristics of the turbine stage - power, speed, efficiency, shaft torque and others is considered. The efficiency of the stage is expressed by the efficiency coefficient, which is determined by the energy losses available in the stage. Losses, in turn, are expressed by losses in each individual element of the turbine stage design. At the same time, it is noted that the losses in the nozzle apparatus are decomposed into friction losses, edge and end losses. The object of the study is the nozzle apparatus of a low-consumption inflow turbine. The subject of the study is the velocity coefficient of the nozzle apparatus of a low-consumption inflow turbine. The research method is numerical simulation of gas flow using computational gas dynamics. The purpose of the study is to compare the value of the speed coefficient of the nozzle apparatus obtained during a physical experiment with the results of numerical modeling of the nozzle apparatus with subsonic (narrowing) channels. The conducted studies have shown that low-consumption inflow turbines are characterized by small sizes that do not allow us to fully carry out a physical experiment. A graph of the dependence of the velocity coefficient of the nozzle apparatus on the Mach number is provided in the study. A good convergence of the values of the velocity coefficient of the nozzle apparatus obtained by the numerical method with the results of the physical experiment has been established. The velocity fields of the flow part of the nozzle apparatus are obtained in the range of the Mach number ranging from 0.66 to 0.88. The possibility of using numerical modeling for this type of nozzle apparatus is concluded.

ENERGY EFFICIENT EQUIPMENT FOR MODERNIZATION OF THE GAS BOILERS POWER 0.1-30 MW

The possibility of modernization of boilers TVH-8M, TVH-8 and NYYSTU-5, operated in Ukraine, with the increasing of their technical and economic indicators to the modern European level is shown. Projects of modernization of boilers have been developed, which consist in redesign of heating surfaces in convective shafts of existing boilers without increasing their overall dimensions with using convective part of pipes diameter 32 x 3 mm and replacement of burner devices by developed new type MPIG-3. It is shown that the results of industrial implementations achieved efficiency of boilers type TVH-8M (TVH-8) 94-96% in the operating range of their load and obtained the calculated efficiency for boilers NYYSTU-5 92-94%. It is experimentally proven that when installing special calibrated nozzle, instead of drilled holes in the collectors of gas burners, it is possible to keep the nozzle geometry (natural gas burner consumption depending on pressure) unchanged throughout the service life. The technical possibility of combustion of biogas and mixtures of natural gas and hydrogen in the slot bottom diffusion burners of the MPIG-3 type, when replacing only the nozzle apparatus is shown. Bibl. 17, Fig. 6, Table 1.

A study and comparison of the modes of diffusion combustion of hydrogen and methane at their outflow from the annular nozzle together with the flow of supplied air from the coaxially located circular nozzle

The article presents qualitative data on the study of the process of diffusion combustion during the outflow of a gas jet from a nozzle apparatus with a certain arrangement of nozzles. The nozzle apparatus is a round nozzle with a straight channel and a coaxially located annular slot. In the experiments, hydrogen or methane was supplied through an annular slot, and the air was supplied through a central circular micro nozzle. The main features of the diffusion combustion of hydrogen and methane during the outflow from the nozzle apparatus are revealed and a qualitative comparison of the processes is carried out. In both cases, at the initial stage, laminar combustion is observed near the nozzle exit and a breakthrough of the flame front occurs with the release of an incombustible mixture of combustible gas and air. At a high flow rate, the flame separates from the nozzle exit. The fundamental difference is that hydrogen exhibits significantly better combustion stabilization characteristics at the nozzle exit.

Generation, validation and application of dynamic load profiles in flow measurement using cavitating Herschel–Venturi nozzles

Today, utility meters for water are tested for measurement behavior at stable operating conditions at specified flow rates as part of the approval process. The measurement error that occurs during start and stop or when changing between flow rates may not be taken into account. In addition, there are new technologies whose measuring behavior under real-world conditions is only known to a limited extend. To take these facts into account, a new method has been developed and tested to determine the measurement behavior of water meters under dynamic load profiles as they occur in the real application. For this purpose, a test rig for flow rate measurement was extended by a cavitation nozzle apparatus and the generation of dynamic load profiles was validated. For the cavitation nozzles used, possible factors influencing the flow rate, such as temperature and purity of the water as well as the upstream pressure were investigated. Using different types of domestic water meters, the applicability of the dynamic test procedure was demonstrated and the measurement behavior of the meters was characterised.

Исследования турбокомпрессоров с общим рабочим колесом для применения в двигателях и энергоустановках

The article deals with the working processes in flowing part of the turbo-compressors with general impeller (TCG) and with two schemes of the flows. The work studies the features of the TCG operation with two schemes of the flows and the gas-dynamic calculation theory development of their flow parts for use in engines and power plants. The tasks to be solved are to investigate two schemes of the flows in the interscapular space of the impeller – direct-flow and counter-flow. If the gas and air flow directions coincide concerning the axis of rotation of the impeller, then the flow pattern in the TCG is direct-flow, with the opposite movement of flows – is counter-flow. The solution to this problem was performed using the developed methods of gas-dynamic calculation of the TCG flow parts. Conclusions. The scientific novelty of the results obtained is as follows: parameters that significantly affect the efficiency of the turbine and compressor parts of the TCG were established and the formula in the form of a general criterion ratio was calculated. The dependence of the correction factor is determined, which considers the effect of the ratio of the impeller width on the average diameter of the working channel of the RK in the compressor section and the turbine section of the TCG. The article contains formulas, with correction factors, for calculating the power factor in the compressor section and the load factor in the turbine section. If the ratio of the grating width to the average diameter of the working channel is overestimated, it is necessary to supplement the formulas with a correction factor that considers the effect of this ratio. Studies have determined that switching from one mode of operation to another – in a certain section of the impeller, accelerates the flow to the required speed. It is especially evident in the compressor working channel of the TCG with a counter-flow pattern. In the turbine section, the gas flow acceleration time does not depend on the flow pattern – the flow is active and accelerates to the required speed in the nozzle apparatus. The given formulas allow calculating the power of the turbine and compressor parts of the impeller to perform an enlarged gas-dynamic calculation of TCG. Studies have determined that TCG can be used in gas turbine engines and the pressurization system of an internal combustion engine.

Структура потока в межлопаточном канале соплового аппарата с поворотной диафрагмой

In the process of developing a numerical study method of a flat flow around a snap line with a rotary diaphragm, calculations were made at various degrees of opening the rotary diaphragm δ and pressure drops on the grille. As a result of calculations, for small degrees, the opening of the rotary diaphragm, complex patterns of the flow were obtained, in the inter-tube channel of the nozzle apparatus. The article presents some results of a numerical study of the supersonic flow in the channel of the nozzle apparatus with the degree of opening the rotary diaphragm δ = (0.15 ÷ 0.3). Modeling and calculating the flow of the working fluid is made using the Fluent software package. The construction of the calculated areas bounded by one inter-tube channel, for varying degrees of opening the diaphragm of the nozzle apparatus. Grids are built for calculated areas. Calculations were carried out for δ = (0.15 ÷ 0.3) and with different degrees of pressure drop on the grille. As a result of the calculations performed, the flow patterns in the inter-tube canal were obtained and behind it, and the distribution of the coefficients of the kinetic energy loss on the lattice front at various degrees of the discovery of the diaphragm at the inlet in the nozzle apparatus. According to the results of the work carried out, the following conclusions can be drawn: the structure of the stream in the inter-tube channel, the nozzle apparatus at small detection of the discovery, is divided into two parts: a supersonic core of the spawth of the blade and a dialing, the vortex zone at the back of the blade; The supersonic thread kernel at certain values of the relative pressure drop on the lattice (or the air flow values through the grid) is separated by shock fronts into several areas; The coefficients of energy loss, for small degrees of discovery, decrease with a decrease in the relative pressure drops (with an increase in the rate of expiration of the flow from the nozzle lattice); The greatest contribution to the magnitude of the loss of kinetic energy is introduced by a vortex zone in the inter-tube channel, and not wave phenomena in the core of the flow; Optimization of the flow part of the nozzle apparatus must be carried out in order to reduce areas with vortex flow. The results obtained in this work will be used to develop a methodology for a numerical study of the spatial flow around the nozzle lattices with rotary diaphragms.

Performance Study of a Bladeless Microturbine

The paper presents a comprehensive numerical and experimental analysis of the Tesla turbine. The turbine rotor had 5 discs with 160 mm in diameter and inter-disc gap equal to 0.75 mm. The nozzle apparatus consisted of 4 diverging nozzles with 2.85 mm in height of minimal cross-section. The investigations were carried out on air in subsonic flow regime for three pressure ratios: 1.4, 1.6 and 1.88. Maximal generated power was equal to 126 W and all power characteristics were in good agreement with numerical calculations. For each pressure ratio, maximal efficiency was approximately the same in the experiment, although numerical methods proved that efficiency slightly dropped with the increase of pressure ratio. Measurements included pressure distribution in the plenum chamber and tip clearance and temperature drop between the turbine’s inlet and the outlet. For each pressure ratio, the lowest value of the total temperature marked the highest efficiency of the turbine, although the lowest static temperature was shifted towards higher rotational speeds. The turbine efficiency could surpass 20% assuming the elimination of the impact of the lateral gaps between the discs and the casing. The presented data can be used as a benchmark for the validation of analytical and numerical models.

Выбор оптимальных газодинамических параметров радиально-осевых турбин при их совместной работе с поршневыми двигателями внутреннего сгорания

The study of radial-axial (centripetal) turbines is important for science and technology. They are widely used in the refrigeration industry, internal combustion engines, and power engineering, both in the form of auxiliary units and in autonomous power units. The article offers a method for selecting the gas-dynamic parameters of the centripetal turbine in order to obtain the highest efficiency and the best size of the turbine. The increased manufacturability of the turbine is provided due to the absence of a straightener at the outlet of the impeller and the use of straight blades in the impeller. The dependence of the efficiency of a centripetal turbine on the profiles of the blades and the radial dimensions of the nozzle apparatus and the impeller, as well as on the length of the impeller blades is investigated. Considering the recommended optimal parameters, the calculation of a pulsed centripetal turbine operating in conjunction with a four-stroke piston internal combustion engine is performed.

Сравнительный анализ судовых дизелей по предельному повышению экономичности при непосредственном управлении расходом воздуха

The paper presents a comparative analysis of the operational parameters and parameters of marine diesel engines obtained as a result of computational and theoretical studies with direct control of air flow using an adjustable turbocharger nozzle to ensure the maximum allowable efficiency of diesel engines. The objects under study are: two-stroke marine diesel engine, operating on the screw characteristics; marine four-stroke diesel working on the screw characteristics; marine four-stroke diesel working on the load characteristics. As a result of the rotation of the blades of the adjustable nozzle in the direction of reducing the angle of their installation the diesel engine efficiency increases. However, the maximum pressure of the cycle also increases, the pressure drop decreases during purging the cylinders, the effective angle of gas exit from the turbine nozzle decreases, and the compressor's surge stability margin changes. There has been studied the design potential of diesel engines for the maximum increase in their efficiency, which made it possible to accept the stable operation of the compressor in all the studied modes. In the course of the research, boundary values were found for the maximum pressure of the diesel cycle, the pressure drop for purging the cylinders and the effective angle of flow exit from the nozzle apparatus, beyond which the specified parameters did not go beyond all the studied modes of operation of diesels. Taking into account the limitations of the greatest potential for improving efficiency in the equity modes of loads has a four-stroke diesel engine, operating on the screw characteristics, the smallest capacity is the same petrol, but working on the load characteristics.

Methods of increasing the reliability of turbine elements

The purpose of the work. Statistical and experimental analysis of coating methods on the turbine nozzle apparatus to increase the temperature regime.
 Research methods. Calculation method of finite elements, experimental.
 The results obtained. Studies have shown that the use of thermally protective coatings TZP thickness of 250 мm with a thermal conductivity of 1 W / mK on the two steps of the turbine can implement one of two possibilities:
 - at constant operating temperature of the blade material to increase the temperature of the gas in front of the turbine by about 100 °C, which will increase efficiency and fuel savings by more than 13 %;- without changing the temperature of the gas in front of the turbine - to increase the durability of the blades by about 4 times, due to a decrease in their operating temperature. The analysis of two methods of drawing TZP was carried out, in the work the estimation of a temperature condition of the nozzle device (CA) of the turbine of a high pressure of the engine, decrease in its temperature due to drawing TZP and increase of its resource is carried out. The problem was solved by applying TZP on the blades of the nozzle apparatus. The analysis of two methods of drawing TZP was carried out, the estimation of a temperature condition of the nozzle device (CA) of the turbine of high pressure of the engine, decrease in its temperature due to drawing TZP and increase of its resource is carried out.
 Scientific novelty. The problem of creating efficient, economical and reliable gas turbines is the most difficult among the many problems that arise in the development of gas turbine construction. Important elements of turbines are working and nozzle blades, the material and design of which determine the allowable gas temperature in front of the turbine and thus directly affect the technical and economic performance of the gas turbine engine.
 Practical value. The obtained results are important for the further development of aircraft engine construction, due to the application of TZP achieved an increase in the resource of CA from 40,000 hours to 67,000 hours.

On the rational form of rotary control diaphragms for steam turbines with industrial and cogeneration steam extraction

The Russian park of power steam turbines contains a large number of turbines with adjustable steam extraction from the flow path where rotary control diaphragms are used as flow controllers, which structurally easily fit into the flow path of these turbines. This method of regulating the steam flow rate is accompanied by a decrease in the efficiency of the subsequent stages of the turbine and causes the appearance, at reduced loads, of additional disturbing forces acting on the rotor blades. In the presented materials, a variant of a post-sampling stage with a radial rotary control diaphragm is considered. The performed mathematical modeling of the working fluid flows in such a stage showed that in this case, at all turbine loads, a relatively uniform velocity field is provided when steam enters the nozzle apparatus, which naturally entails the elimination of the noted drawbacks.

Investigation of the cascade mechanism of energy exchange in swirling gas flows based on the effect of secondary swirling

The article presents the results of studies of the secondary swirling effect in supersonic rotating gas and plasma flows. It is shown that the secondary twist of the jets of gas flowing from the nozzle apparatus generates a cascade structure of vortices that separate energy in the field of azimuthal and radial pressure gradients. As shown by the calculations, the effect of energy separation is more significant the higher the level of secondary twisting of the nozzle jets, which, in turn, is determined by the level of energy dissipation. Experimental confirmations of the revealed cascade mechanism of energy separation in supersonic swirling gas flows are discussed.