Pub Date : 2022-07-07DOI: 10.18287/2541-7533-2022-21-2-109-114
A. S. Smekalkin, A. Ivanov
The supercharger is intended for heating a fluid (gaseous helium or gaseous nitrogen) used for the pressurization of fuel tanks of oxidizer and propellant of a rocket engine. The fluid is heated with the generator gas downstream the turbine. A supercharger with increased channel surface roughness was made according to an additive technology. High roughness is one of the features of producing parts by selective laser melting. The article presents a method of calculating the heat transfer of generator gas and nitrogen, as well as the results of heat transfer both with and without account of the surface roughness in the channels of the liquid-propellant engines additively manufactured supercharger. Firing tests were carried out at the research base of NPO Energomash JSC. The calculated and experimental values of the temperature of the working medium at the outlet of the supercharger are compared.
{"title":"Influence of surface roughness on the heat transfer coefficient of fluids in an additively manufactured supercharger","authors":"A. S. Smekalkin, A. Ivanov","doi":"10.18287/2541-7533-2022-21-2-109-114","DOIUrl":"https://doi.org/10.18287/2541-7533-2022-21-2-109-114","url":null,"abstract":"The supercharger is intended for heating a fluid (gaseous helium or gaseous nitrogen) used for the pressurization of fuel tanks of oxidizer and propellant of a rocket engine. The fluid is heated with the generator gas downstream the turbine. A supercharger with increased channel surface roughness was made according to an additive technology. High roughness is one of the features of producing parts by selective laser melting. The article presents a method of calculating the heat transfer of generator gas and nitrogen, as well as the results of heat transfer both with and without account of the surface roughness in the channels of the liquid-propellant engines additively manufactured supercharger. Firing tests were carried out at the research base of NPO Energomash JSC. The calculated and experimental values of the temperature of the working medium at the outlet of the supercharger are compared.","PeriodicalId":265584,"journal":{"name":"VESTNIK of Samara University. Aerospace and Mechanical Engineering","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132899458","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-07-07DOI: 10.18287/2541-7533-2022-21-2-38-47
M. Cherkasova, E. Semakina, V. Chernikov
The efficiency of a gas turbine largely depends on the aerodynamics and pressure recovery capacity of the diffuser. For reliable numerical simulation of the flow in the diffuser, the model must be validated on the basis of experimental data on the flow structure. An experimental and numerical study of the stage diffuser system was carried out. The results of this investigation are as follows: the area of applicability of the numerical method for assessing the flow in the stage diffuser system was determined; recommendations for preparing a numerical model and transferring boundary conditions from domain to domain were developed; the importance of profiling the last turbine stage to ensure unseparated flow entry into the diffuser is indicated; the influence of the hub length and the geometry of the struts on the losses in the diffuser and its pressure recovery capacity is determined. It is shown that increasing the hub length to certain limits improves the pressure recovery ratio of the diffuser. The smallest thickness of the struts gives the best results; the tangential and axial slope of the struts does not make a significant contribution in the nominal operating mode of the gas turbine.
{"title":"Validation of the “stage – diffuser” system numerical study and its use for design modernization","authors":"M. Cherkasova, E. Semakina, V. Chernikov","doi":"10.18287/2541-7533-2022-21-2-38-47","DOIUrl":"https://doi.org/10.18287/2541-7533-2022-21-2-38-47","url":null,"abstract":"The efficiency of a gas turbine largely depends on the aerodynamics and pressure recovery capacity of the diffuser. For reliable numerical simulation of the flow in the diffuser, the model must be validated on the basis of experimental data on the flow structure. An experimental and numerical study of the stage diffuser system was carried out. The results of this investigation are as follows: the area of applicability of the numerical method for assessing the flow in the stage diffuser system was determined; recommendations for preparing a numerical model and transferring boundary conditions from domain to domain were developed; the importance of profiling the last turbine stage to ensure unseparated flow entry into the diffuser is indicated; the influence of the hub length and the geometry of the struts on the losses in the diffuser and its pressure recovery capacity is determined. It is shown that increasing the hub length to certain limits improves the pressure recovery ratio of the diffuser. The smallest thickness of the struts gives the best results; the tangential and axial slope of the struts does not make a significant contribution in the nominal operating mode of the gas turbine.","PeriodicalId":265584,"journal":{"name":"VESTNIK of Samara University. Aerospace and Mechanical Engineering","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123750097","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-07-07DOI: 10.18287/2541-7533-2022-21-2-16-27
Yu. G. Gorelov, V. Ananyev, D. A. Zolotuhina
Turbine nozzle blocks were tested and, as a result, problems of nozzle block lower platform alligatoring were detected. In the course of the research possible variants of cooling high pressure turbine nozzle block vane platforms were investigated. According to the results of 3D ANSYS CFX calculation the cooling efficiency of high pressure turbine vane platforms with film cooling and convective-film cooling were compared. Research was carried out to eliminate the alligatoring defect of the lower vane platform with convective cooling. Necessary changes in the design were made due to which the cooling air from the secondary combustion chamber area was redistributed over the surface of the turbine nozzle block lower platform. To force the gas turbine engine to the inlet gas temperature to 1800К and more, and to increase the cooling air mass flow from the secondary combustion chamber area over the platforms using convective cooling methods not requiring developed ribbing and impingement cooling, areas of the platforms, as well as zones demanding insignificant intensity of cooling are shown.
{"title":"3D investigation of heat exchange and hydrodynamics of high pressure turbine nozzle block platforms with different cooling schemes","authors":"Yu. G. Gorelov, V. Ananyev, D. A. Zolotuhina","doi":"10.18287/2541-7533-2022-21-2-16-27","DOIUrl":"https://doi.org/10.18287/2541-7533-2022-21-2-16-27","url":null,"abstract":"Turbine nozzle blocks were tested and, as a result, problems of nozzle block lower platform alligatoring were detected. In the course of the research possible variants of cooling high pressure turbine nozzle block vane platforms were investigated. According to the results of 3D ANSYS CFX calculation the cooling efficiency of high pressure turbine vane platforms with film cooling and convective-film cooling were compared. Research was carried out to eliminate the alligatoring defect of the lower vane platform with convective cooling. Necessary changes in the design were made due to which the cooling air from the secondary combustion chamber area was redistributed over the surface of the turbine nozzle block lower platform. To force the gas turbine engine to the inlet gas temperature to 1800К and more, and to increase the cooling air mass flow from the secondary combustion chamber area over the platforms using convective cooling methods not requiring developed ribbing and impingement cooling, areas of the platforms, as well as zones demanding insignificant intensity of cooling are shown.","PeriodicalId":265584,"journal":{"name":"VESTNIK of Samara University. Aerospace and Mechanical Engineering","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116982925","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-07-07DOI: 10.18287/2541-7533-2022-21-2-80-92
E. F. Parovay
High heat generation in the hydrodynamic wedge is one of the main factors limiting application of pad journal bearings as bearings for rotors of aircraft gas turbine engines. The goal of the research is to study the influence of the oil supply method on the bearing thermal state and to determine the design factors reducing the bearing temperature. The study was carried out with the use of bearings with diameters of 100320 mm with different design of the oil supply: through oil dispensing grooves in the pads, through oil nozzles in the inter-pad space, using lead-in chamfers for the pads, with oil bypass channels. The tasks posed were solved by using volumetric geometric models with the tools of computational fluid dynamics in the ANSYS CFX package in which differential equations describing the model are solved by the finite element method. The patterns of temperature and pressure distribution over the surface of the lower, most loaded bearing pad were obtained for various options of oil supply and different geometry of bearing pads; values of the bearing load carrying capacity, maximum pressure in the working gap, the oil mass flow through the elements of the oil supply; dependences of the bearing static performance on the distance between the shaft and nozzles. Oil supply through oil dispensing grooves made in pads is a factor that negatively affects the bearing thermal state, which is associated with so-called locking of the working gap. It is shown that implementation of oil supply through the space between the pads is more efficient. The use of a lead-in chamfer with plain inserts simplifies oil supply to the working gap. The design solutions described make it possible to reduce the maximum oil temperature in the bearing by 36 degrees Celsius.
{"title":"Influence of pad geometry and method of oil supply on the thermal state of GTE rotor tilting-pad journal bearing","authors":"E. F. Parovay","doi":"10.18287/2541-7533-2022-21-2-80-92","DOIUrl":"https://doi.org/10.18287/2541-7533-2022-21-2-80-92","url":null,"abstract":"High heat generation in the hydrodynamic wedge is one of the main factors limiting application of pad journal bearings as bearings for rotors of aircraft gas turbine engines. The goal of the research is to study the influence of the oil supply method on the bearing thermal state and to determine the design factors reducing the bearing temperature. The study was carried out with the use of bearings with diameters of 100320 mm with different design of the oil supply: through oil dispensing grooves in the pads, through oil nozzles in the inter-pad space, using lead-in chamfers for the pads, with oil bypass channels. The tasks posed were solved by using volumetric geometric models with the tools of computational fluid dynamics in the ANSYS CFX package in which differential equations describing the model are solved by the finite element method. The patterns of temperature and pressure distribution over the surface of the lower, most loaded bearing pad were obtained for various options of oil supply and different geometry of bearing pads; values of the bearing load carrying capacity, maximum pressure in the working gap, the oil mass flow through the elements of the oil supply; dependences of the bearing static performance on the distance between the shaft and nozzles. Oil supply through oil dispensing grooves made in pads is a factor that negatively affects the bearing thermal state, which is associated with so-called locking of the working gap. It is shown that implementation of oil supply through the space between the pads is more efficient. The use of a lead-in chamfer with plain inserts simplifies oil supply to the working gap. The design solutions described make it possible to reduce the maximum oil temperature in the bearing by 36 degrees Celsius.","PeriodicalId":265584,"journal":{"name":"VESTNIK of Samara University. Aerospace and Mechanical Engineering","volume":"102 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121341977","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-07-07DOI: 10.18287/2541-7533-2022-21-2-65-79
V. Komarov, A. Pavlov, S. Pavlova
The challenge of determining nine elastic characteristics of orthotropic woven composites is considered. Using a test example, the influence of transverse elastic characteristics on the results of the stress-strain state analysis of composite structures is assessed. To determine the transverse elastic constants of an orthotropic woven composite, we propose to use a representative volume of the materials repeated structure. The features of creating a finite element model of a representative volume of a layered woven composite are considered. To determine the elastic properties of an orthotropic woven composite, kinematic boundary conditions of a special type and calculation ratios are proposed that virtually simulate a mechanical experiment with a representative volume of material. The results of comparison of the calculated characteristics and field test data by standard methods are presented, which indicate the possibility of predicting transverse elastic characteristics by computational methods with a sufficiently high accuracy for use in practical tasks.
{"title":"Experimental and analytical determination of the elastic characteristics of layered woven composites","authors":"V. Komarov, A. Pavlov, S. Pavlova","doi":"10.18287/2541-7533-2022-21-2-65-79","DOIUrl":"https://doi.org/10.18287/2541-7533-2022-21-2-65-79","url":null,"abstract":"The challenge of determining nine elastic characteristics of orthotropic woven composites is considered. Using a test example, the influence of transverse elastic characteristics on the results of the stress-strain state analysis of composite structures is assessed. To determine the transverse elastic constants of an orthotropic woven composite, we propose to use a representative volume of the materials repeated structure. The features of creating a finite element model of a representative volume of a layered woven composite are considered. To determine the elastic properties of an orthotropic woven composite, kinematic boundary conditions of a special type and calculation ratios are proposed that virtually simulate a mechanical experiment with a representative volume of material. The results of comparison of the calculated characteristics and field test data by standard methods are presented, which indicate the possibility of predicting transverse elastic characteristics by computational methods with a sufficiently high accuracy for use in practical tasks.","PeriodicalId":265584,"journal":{"name":"VESTNIK of Samara University. Aerospace and Mechanical Engineering","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131246007","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-04-27DOI: 10.18287/2541-7533-2022-21-1-24-33
M. Artamonov, A. A. Govorov, D. Starshinov
To maintain the functionality of fan blades, it is important to know the distribution of dynamic stresses in the blade, their amplitude and vibration frequency. Understanding of the dynamic loading pattern will allow us to determine under what conditions the engine was operated, to identify and prevent emergencies that could lead to the blade fracture. The purpose of this work is to understand the cause of the fan blade fracture that occurred during the engine ground start. Due to fractographic analysis of blade fragments it was revealed that the fracture occurred due to the initiation of fatigue cracks in blades. The place of crack initiation and parameters of crack growth were established, spectral analysis of the fracture was carried out. To establish the reason of fatigue crack initiation it was necessary to determine the dynamic state of the blades during their destruction. The sections of the second stage of stable crack growth, during which fatigue striations are formed, were determined using the fractographic method. Using the spacing of the fatigue striations and Paris's law, the crack stress intensity range was determined. Modeling of crack propagation in the blade was carried out to define the stress state. The ability to determine the stress intensity factor at each step of crack growth and its comparison with research data made this work possible. The simulation showed under what conditions manifold increase in stresses occurs and made it possible to obtain the expected value of vibration amplitude. Additional modal analysis showed a resonant form that caused the fatigue nature of crack propagation. The demonstrated approach established crack growth conditions and revealed the cause of blade fracture.
{"title":"Reconstruction of fan blade dynamic loading prior to its fracture","authors":"M. Artamonov, A. A. Govorov, D. Starshinov","doi":"10.18287/2541-7533-2022-21-1-24-33","DOIUrl":"https://doi.org/10.18287/2541-7533-2022-21-1-24-33","url":null,"abstract":"To maintain the functionality of fan blades, it is important to know the distribution of dynamic stresses in the blade, their amplitude and vibration frequency. Understanding of the dynamic loading pattern will allow us to determine under what conditions the engine was operated, to identify and prevent emergencies that could lead to the blade fracture. The purpose of this work is to understand the cause of the fan blade fracture that occurred during the engine ground start. Due to fractographic analysis of blade fragments it was revealed that the fracture occurred due to the initiation of fatigue cracks in blades. The place of crack initiation and parameters of crack growth were established, spectral analysis of the fracture was carried out. To establish the reason of fatigue crack initiation it was necessary to determine the dynamic state of the blades during their destruction. The sections of the second stage of stable crack growth, during which fatigue striations are formed, were determined using the fractographic method. Using the spacing of the fatigue striations and Paris's law, the crack stress intensity range was determined. Modeling of crack propagation in the blade was carried out to define the stress state. The ability to determine the stress intensity factor at each step of crack growth and its comparison with research data made this work possible. The simulation showed under what conditions manifold increase in stresses occurs and made it possible to obtain the expected value of vibration amplitude. Additional modal analysis showed a resonant form that caused the fatigue nature of crack propagation. The demonstrated approach established crack growth conditions and revealed the cause of blade fracture.","PeriodicalId":265584,"journal":{"name":"VESTNIK of Samara University. Aerospace and Mechanical Engineering","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126386438","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-04-27DOI: 10.18287/2541-7533-2022-21-1-81-90
A. Solodovnikov, D. A. Odentsov, E. V. Kravtsov, V. V. Golubyatnik, D. A. Shcheblykin
Due to insufficient knowledge of the processes occurring in the chambers of pulsating combustion, as well as lack of mathematical dependencies that make it possible to fully describe the parameters of such chambers, the authors of this article present a model for calculating pressure fluctuations as a function of time. The resulting dependence is based on the fact that the combustion of fuel takes place according to an isochoric cycle, whereas the outflow of gas through a resonant tube is an isothermal process. The conditions for applying the mathematical model and its features are described. With the help of the above dependence, it is possible to trace the dynamics of pressure changes during the operation of a pulsating combustion chamber with different geometric parameters. A program is presented that implements the obtained dependence for calculating and comparing the obtained theoretical data with the studies of other authors.
{"title":"Mathematical model for calculating pressure in a pulsating combustion chamber","authors":"A. Solodovnikov, D. A. Odentsov, E. V. Kravtsov, V. V. Golubyatnik, D. A. Shcheblykin","doi":"10.18287/2541-7533-2022-21-1-81-90","DOIUrl":"https://doi.org/10.18287/2541-7533-2022-21-1-81-90","url":null,"abstract":"Due to insufficient knowledge of the processes occurring in the chambers of pulsating combustion, as well as lack of mathematical dependencies that make it possible to fully describe the parameters of such chambers, the authors of this article present a model for calculating pressure fluctuations as a function of time. The resulting dependence is based on the fact that the combustion of fuel takes place according to an isochoric cycle, whereas the outflow of gas through a resonant tube is an isothermal process. The conditions for applying the mathematical model and its features are described. With the help of the above dependence, it is possible to trace the dynamics of pressure changes during the operation of a pulsating combustion chamber with different geometric parameters. A program is presented that implements the obtained dependence for calculating and comparing the obtained theoretical data with the studies of other authors.","PeriodicalId":265584,"journal":{"name":"VESTNIK of Samara University. Aerospace and Mechanical Engineering","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129507624","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-04-27DOI: 10.18287/2541-7533-2022-21-1-67-80
A. Maksimov, S. Shustov
A numerical method for thermogasdynamic calculation of low-thrust liquid rocket engines is presented. These engines are used as end organs of the system of space attitude control for nanosatellites and small spacecraft. The method is based on the use of the TERRA software package for thermodynamic calculation and the Ansys CFX software package for gas-dynamic calculation using the Navier-Stokes equations. The results of the thermogasdynamic calculation, as well as the flow pattern of the working fluid in the chamber, are presented. The results of validating the described method are also presented. Its capabilities and limitations are analyzed. The validation procedure is based on the comparison with the results of experimental data on the Reynolds number and the momentum thickness.
{"title":"On the efficiency of using the Navier-Stokes approximation in thermogasdynamic calculation of low-thrust liquid-propellant rocket engines at low Reynolds numbers","authors":"A. Maksimov, S. Shustov","doi":"10.18287/2541-7533-2022-21-1-67-80","DOIUrl":"https://doi.org/10.18287/2541-7533-2022-21-1-67-80","url":null,"abstract":"A numerical method for thermogasdynamic calculation of low-thrust liquid rocket engines is presented. These engines are used as end organs of the system of space attitude control for nanosatellites and small spacecraft. The method is based on the use of the TERRA software package for thermodynamic calculation and the Ansys CFX software package for gas-dynamic calculation using the Navier-Stokes equations. The results of the thermogasdynamic calculation, as well as the flow pattern of the working fluid in the chamber, are presented. The results of validating the described method are also presented. Its capabilities and limitations are analyzed. The validation procedure is based on the comparison with the results of experimental data on the Reynolds number and the momentum thickness.","PeriodicalId":265584,"journal":{"name":"VESTNIK of Samara University. Aerospace and Mechanical Engineering","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114262581","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-04-27DOI: 10.18287/2541-7533-2022-21-1-34-41
A. S. Bukatyi, S. A. Bukatyi
In the framework of this research it is shown that strength calculation of the most critical parts requires taking into account the parameter of stress state stiffness determined by the G. A. Smirnov-Alyaev. A method for estimating the level of strain of parts and diagnosing the most critical zones of parts based on dimensionless energy and complex criteria is proposed. The effectiveness of the method that can be used not only to diagnose critical zones, but also to optimize the geometric parameters of the design of critical parts, is shown.
在本研究的框架下，表明了最关键部件的强度计算需要考虑G. A. Smirnov-Alyaev确定的应力状态刚度参数。提出了一种基于无因次能量和复杂准则的零件应变水平估计和零件最关键区域诊断方法。结果表明，该方法不仅可用于诊断临界区域，而且可用于关键零件设计的几何参数优化。
{"title":"Strength calculation of parts based on stress state stiffness","authors":"A. S. Bukatyi, S. A. Bukatyi","doi":"10.18287/2541-7533-2022-21-1-34-41","DOIUrl":"https://doi.org/10.18287/2541-7533-2022-21-1-34-41","url":null,"abstract":"In the framework of this research it is shown that strength calculation of the most critical parts requires taking into account the parameter of stress state stiffness determined by the G. A. Smirnov-Alyaev. A method for estimating the level of strain of parts and diagnosing the most critical zones of parts based on dimensionless energy and complex criteria is proposed. The effectiveness of the method that can be used not only to diagnose critical zones, but also to optimize the geometric parameters of the design of critical parts, is shown.","PeriodicalId":265584,"journal":{"name":"VESTNIK of Samara University. Aerospace and Mechanical Engineering","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116960685","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-04-27DOI: 10.18287/2541-7533-2022-21-1-91-98
A. Sundukov, Ye. V. Shakhmatov
Vibration-acoustic diagnostics of rotary machine defects is the most effective method for non-destructive testing of their technical condition. Practice shows that its successful use largely depends on a set of available methods for analyzing vibration processes. Gears are the most common and heavy-duty components that largely determine the overall vibratory condition of a machine. There is quite a variety of methods for vibration-based diagnostics of gear defects. They include an interesting method of bipolar analysis which consists in separate analysis of the positive and negative parts of a vibration signal with subsequent formation of the diagnostic indicator in the form of differences, ratios, etc. The method is aimed at assessing the quality of gearbox assembly by the position of the tooth contact pattern. Limited area of use and low sensitivity is a disadvantage of this method. The paper shows that the use of broadband vibration maxima in the application of bipolar analysis in vibration-based diagnostics of rotary machine defects significantly increases its efficiency. Using the example of wear of tooth flanks in the sun gear satellite gears pair and the value of the backlash in the differential gearbox of a turboprop engine, it was found to be ensured by increasing the sensitivity of the method and expanding its functionality. In our analysis, we used statistics of gearboxes with different degrees of wear of the tooth flanks and repaired gearboxes with different backlashes. In this case, a wide set of well-known diagnostic indicators can be used: intensity of n-dimensional vectors of informative series, parameters of individual harmonics, amplitude modulation depth, probabilistic characteristics in selected frequency bands, dimensionless discriminants, cepstra, etc. The paper presents some examples of these methods.
{"title":"Increasing the sensitivity and expanding the functionality of bipolar analysis of rotary machine vibrations","authors":"A. Sundukov, Ye. V. Shakhmatov","doi":"10.18287/2541-7533-2022-21-1-91-98","DOIUrl":"https://doi.org/10.18287/2541-7533-2022-21-1-91-98","url":null,"abstract":"Vibration-acoustic diagnostics of rotary machine defects is the most effective method for non-destructive testing of their technical condition. Practice shows that its successful use largely depends on a set of available methods for analyzing vibration processes. Gears are the most common and heavy-duty components that largely determine the overall vibratory condition of a machine. There is quite a variety of methods for vibration-based diagnostics of gear defects. They include an interesting method of bipolar analysis which consists in separate analysis of the positive and negative parts of a vibration signal with subsequent formation of the diagnostic indicator in the form of differences, ratios, etc. The method is aimed at assessing the quality of gearbox assembly by the position of the tooth contact pattern. Limited area of use and low sensitivity is a disadvantage of this method. The paper shows that the use of broadband vibration maxima in the application of bipolar analysis in vibration-based diagnostics of rotary machine defects significantly increases its efficiency. Using the example of wear of tooth flanks in the sun gear satellite gears pair and the value of the backlash in the differential gearbox of a turboprop engine, it was found to be ensured by increasing the sensitivity of the method and expanding its functionality. In our analysis, we used statistics of gearboxes with different degrees of wear of the tooth flanks and repaired gearboxes with different backlashes. In this case, a wide set of well-known diagnostic indicators can be used: intensity of n-dimensional vectors of informative series, parameters of individual harmonics, amplitude modulation depth, probabilistic characteristics in selected frequency bands, dimensionless discriminants, cepstra, etc. The paper presents some examples of these methods.","PeriodicalId":265584,"journal":{"name":"VESTNIK of Samara University. Aerospace and Mechanical Engineering","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134012923","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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