VESTNIK of Samara University. Aerospace and Mechanical Engineering最新文献_第10页

Influence of surface roughness on the heat transfer coefficient of fluids in an additively manufactured supercharger 增材制造增压器中表面粗糙度对流体传热系数的影响

VESTNIK of Samara University. Aerospace and Mechanical Engineering Pub Date : 2022-07-07 DOI: 10.18287/2541-7533-2022-21-2-109-114

A. S. Smekalkin, A. Ivanov

引用次数: 0

Validation of the “stage – diffuser” system numerical study and its use for design modernization “级-扩散器”系统数值研究的验证及其在设计现代化中的应用

VESTNIK of Samara University. Aerospace and Mechanical Engineering Pub Date : 2022-07-07 DOI: 10.18287/2541-7533-2022-21-2-38-47

M. Cherkasova, E. Semakina, V. Chernikov

{"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}

引用次数: 0

3D investigation of heat exchange and hydrodynamics of high pressure turbine nozzle block platforms with different cooling schemes 不同冷却方案下高压涡轮喷嘴块平台换热及流体力学的三维研究

VESTNIK of Samara University. Aerospace and Mechanical Engineering Pub Date : 2022-07-07 DOI: 10.18287/2541-7533-2022-21-2-16-27

Yu. G. Gorelov, V. Ananyev, D. A. Zolotuhina

{"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}

引用次数: 0

Influence of pad geometry and method of oil supply on the thermal state of GTE rotor tilting-pad journal bearing 垫块几何形状和供油方式对GTE转子斜垫滑动轴承热状态的影响

VESTNIK of Samara University. Aerospace and Mechanical Engineering Pub Date : 2022-07-07 DOI: 10.18287/2541-7533-2022-21-2-80-92

E. F. Parovay

{"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}

引用次数: 0

Experimental and analytical determination of the elastic characteristics of layered woven composites 层织复合材料弹性特性的实验与分析

VESTNIK of Samara University. Aerospace and Mechanical Engineering Pub Date : 2022-07-07 DOI: 10.18287/2541-7533-2022-21-2-65-79

V. Komarov, A. Pavlov, S. Pavlova

引用次数: 1

Reconstruction of fan blade dynamic loading prior to its fracture 扇叶断裂前动载荷重建

VESTNIK of Samara University. Aerospace and Mechanical Engineering Pub Date : 2022-04-27 DOI: 10.18287/2541-7533-2022-21-1-24-33

M. Artamonov, A. A. Govorov, D. Starshinov

{"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}

引用次数: 0

Mathematical model for calculating pressure in a pulsating combustion chamber 脉动燃烧室压力计算的数学模型

VESTNIK of Samara University. Aerospace and Mechanical Engineering Pub Date : 2022-04-27 DOI: 10.18287/2541-7533-2022-21-1-81-90

A. Solodovnikov, D. A. Odentsov, E. V. Kravtsov, V. V. Golubyatnik, D. A. Shcheblykin

引用次数: 0

On the efficiency of using the Navier-Stokes approximation in thermogasdynamic calculation of low-thrust liquid-propellant rocket engines at low Reynolds numbers Navier-Stokes近似在低雷诺数低推力液体推进剂火箭发动机热气动力学计算中的效率

VESTNIK of Samara University. Aerospace and Mechanical Engineering Pub Date : 2022-04-27 DOI: 10.18287/2541-7533-2022-21-1-67-80

A. Maksimov, S. Shustov

引用次数: 0

Strength calculation of parts based on stress state stiffness 基于应力状态刚度的零件强度计算

VESTNIK of Samara University. Aerospace and Mechanical Engineering Pub Date : 2022-04-27 DOI: 10.18287/2541-7533-2022-21-1-34-41

A. S. Bukatyi, S. A. Bukatyi

引用次数: 0

Increasing the sensitivity and expanding the functionality of bipolar analysis of rotary machine vibrations 提高旋转机械振动双极分析的灵敏度和扩展功能

VESTNIK of Samara University. Aerospace and Mechanical Engineering Pub Date : 2022-04-27 DOI: 10.18287/2541-7533-2022-21-1-91-98

A. Sundukov, Ye. V. Shakhmatov

{"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}

引用次数: 0