20 research outputs found
Performance Assessment of the Thermodynamic Cycle in a Multi-Mode Gas Turbine Engine
This chapter discusses the direction of development of promising multimode aviation gas turbine engines (GTE). It is shown that the development of GTE is on the way to increase the parameters engine workflow: gas temperatures in front of the turbine (T*G) and the degree of pressure increase in the compressor (P*C). It is predicted that the next generation engines will operate with high parameters of the working process, T*GĀ =Ā 2000ā2200Ā K, Ļ*CĀ =Ā 60ā80. At this temperature of gases in front of the turbine, the working mixture in the combustion chamber (CC) is stoichiometric, which sharply narrows the range of stable operation of the CC and its efficiency drops sharply in off-design gas turbine engine operation modes. To expand the range of effective and stable work, it is proposed to use an advanced aviation GTE: Adaptive Type Combustion Chamber (ATCC). A scheme of the ATCC and the principles of its regulation in the system of a multi-mode gas turbine engine are presented. The concept of an adaptive approach is given in this article. There are two main directions for improving the characteristics of a promising aviation gas turbine engine. One is a complication of the concepts of aircraft engines and the other one is an increase in the parameters of the working process, the temperature of the gases in front of the turbine (T*G) and the degree of increasing pressure behind the compressor (Ļ*C). It is shown how the principles of adaptation are used in these areas. The application of the adaptation principle in resolving the contradiction of the possibility of obtaining optimal characteristics of a high-temperature combustion chamber (CC) of a gas turbine engine under design (optimal) operating conditions and the impossibility of their implementation when these conditions change in the range of acceptable (non-design) gas turbine operation modes is considered in detail. The use of an adaptive approach in the development of promising gas turbine engines will significantly improve their characteristics and take into account unknown challenges
Štances formveidojoŔo detaļu izgatavoŔanas tehnoloģija, pielietojot CNC darbagaldus
MÅ«sdienÄs projektÄjot detaļu mehÄniskas apstrÄdes tehnoloÄ£iskus procesus, mehÄnismu un maŔīnas salÄ«kÅ”anu liels akcents tiek likts uz galveno mÄrÄ·i- kvalitatÄ«vu izstrÄdÄjumu ražoÅ”ana, Åemot vÄrÄ ražoÅ”anas augsto tempu un optimÄlas paÅ”izmaksas. LielsÄriju un masveidÄ apstÄkļos dotie parametri tiek sasniegti izmantojot darbgaldus ar revolvergalvÄm un vairÄku pozÄ«ciju, automÄtus ā automÄtiskÄs lÄ«nijÄs tehnoloÄ£isko procesu mehanizÄcijas un automatizÄcijas dÄļ, bet salikÅ”anai- izmantojot automatizÄto un mehanizÄto kompleksus vai lÄ«nijas. Bet automÄtu, pusautomÄtu un automÄtisko lÄ«niju izmantoÅ”ana nav pieļaujama, Åemot vÄrÄ paÅ”u aprÄ«kojumu augstas cenas, viÅu tehnoloÄ£isko aprÄ«kojumu, un ilgstoÅ”as un lielas darba apjomÄ«gas operÄcijas, parejot no viena veida produkcijas ražoÅ”anas pie citas. Galu galÄ izstrÄdÄjumu paÅ”izmaksas mazserijÄ paliek nesalÄ«dzinÄmi augstas, jo visi patÄriÅi tiek iekļauti tajÄ.
SakarÄ ar to, nelielo partiju sagatavju apstrÄdes tehnoloÄ£iska procesa automatizÄcijas novirze ir cieÅ”i saistÄ«ta ar datorvadÄ«bu darbgaldu pielietoÅ”anu
The Experimental Study of High Chrome Content Steel Processing
Stainless steels are generally difficult to machine due to their high tensile strength, high ductility, high work hardening rate, low thermal conductivity, and abrasive character. This combination of properties often results in cutting forces, temperatures, and tool wear rates, as well as a susceptibility to notch wear, chip-breaking difficulties, BUE for-mation, and poor machined surface finish. One more problem is the high chrome content which effect chip formation process and may seriously cause machining process. The aim of the experiment is to study the machining parameters and machined result
PlÄno slÄÅu gumijas-metÄla amortizatoru paketes stabilitÄtes pÄtÄ«jumi
ja ir jÄiegust lielas nbÄ«des deformÄcijas, izmanto plÄnu slÄÅu gumijas -metÄla elementus, kuru augstums ir daudz lielÄks par pamata izmÄru. Å Ädam elementam darbojoties zem liela spiediena, notiek vidÄjo elementu slÄÅu izspieÅ”ana jeb gareÅstabilitÄtes zaudÄjums, kas rada nekontrolÄjamu slÄÅu nobÄ«di
Stainless Steel Machining with Nanocoated Duratomic Cutting Tools
Stainless steels are generally difficult to machine due to their high tensile strength, high ductility, high work hardening rate, low thermal conductivity, and abrasive character. This combination of properties often results in cutting forces, temperatures, and tool wear rates, as well as a susceptibility to notch wear, chip-breaking difficulties, BUE formation, and poor machined surface finish. The aim of the experiment is to study the machining parameters and machined result
Roughness Parameters of Elastic Materials in Analysis of Measuring Errors
Recently, role of the rubber as a construction material has significantly increased in
mechatronical systems. Rubber among the polymers is the oldest material in use. There is a
deformation of elastic materials under the impact of measuring force described in this paper taking
into consideration the surface roughness.
Surface roughness is described by the normal random field which correlation function is
monotonically decreasing. There are the main height parameters and spacings of 3D field examined in
the paper. The set of 3D roughness parameters is chosen that is used to determine the errors of
measurement
Research on Bucket Bore Renewal Technologies
Novel mobile (in-situ) repair technologies are extensively used for specialized equipment and machinery repairs. The reason for this is the considerable cost reductions and increase in the technological lifespan of the industrial equipment. Such parts as frames, joints or buckets can be renewed to an excellent standard using innovative in-situ technologies.
In-situ renovation technology is itself a non-standard operation, even though the techniques used of turning and installation are relatively well studied and developed. Conversely, build-up welding processes can be studied further and potentially substituted by more advanced and economically more attractive, modern surface renovation technologies
ElastomÄra amortizatora stinguma aprÄÄ·ins, Åemot vÄrÄ tÄ starpslÄÅa deformÄciju
DarbÄ apskatÄ«ta stinguma raksturojuma āspÄks - nosÄdeā iegÅ«Å”anas metodika plÄno slÄÅu elastomÄra amortizatoriem, kas strÄdÄ uz stiepi-spiedi, ievÄrojot neelastomÄra slÄÅu deformÄcijas. Ir paradÄ«ts, ka neelastomÄru slÄÅu deformÄcijas neievÄroÅ”ana var radÄ«t nozÄ«mÄ«gas kļūdas izstrÄdÄjumu nosÄdes aprÄÄ·inÄÅ”anÄ. Pielietota lineÄrÄs stinguma teorijas variÄcijas metode vÄji saspiežamiem materiÄliem. Uzdevumu risinÄm ar variÄcijas metodi, pielietojot potenciÄlÄs enerÄ£ijas minimuma principu vÄji saspiežamiem materiÄliem. Å ajÄ darbÄ piedÄvÄts viens no aprÄÄ·ina shÄmas variantiem, kurÅ” ļauj novÄrtÄt neelastomÄra slÄÅa deformÄcijas ietekmi uz izstrÄdÄjumu stinguma raksturojumiem pie stiepes un spiedes mazo deformÄciju apgabalÄ. IegÅ«tÄs analÄ«tiskÄs atkarÄ«bas rekomendÄ pielietot kompensÄjoÅ”o daudzslÄÅu izstrÄdÄjumu projektÄÅ”anÄ