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*G = 2000–2200 K, π*C = 60–80. 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 (π*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 formveidojošo detaļu izgatavošanas tehnoloģija, pielietojot CNC darbagaldus

Mūsdienās projektējot detaļu mehāniskas apstrādes tehnoloģiskus procesus, mehānismu un mašīnas salīkšanu liels akcents tiek likts uz galveno mērķi- kvalitatīvu izstrādājumu ražošana, ņemot vērā ražošanas augsto tempu un optimālas pašizmaksas. Lielsēriju un masveidā apstākļos dotie parametri tiek sasniegti izmantojot darbgaldus ar revolvergalvām un vairāku pozīciju, automātus – automātiskās līnijās tehnoloģisko procesu mehanizācijas un automatizācijas dēļ, bet salikšanai- izmantojot automatizēto un mehanizēto kompleksus vai līnijas. Bet automātu, pusautomātu un automātisko līniju izmantošana nav pieļaujama, ņemot vērā pašu aprīkojumu augstas cenas, viņu tehnoloģisko aprīkojumu, un ilgstošas un lielas darba apjomīgas operācijas, parejot no viena veida produkcijas ražošanas pie citas. Galu galā izstrādājumu pašizmaksas mazserijā paliek nesalīdzināmi augstas, jo visi patēriņi tiek iekļauti tajā. Sakarā ar to, nelielo partiju sagatavju apstrādes tehnoloģiska procesa automatizācijas novirze ir cieši saistīta ar datorvadību darbgaldu pielietošanu

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

Plāno slāņu gumijas-metāla amortizatoru paketes stabilitātes pētījumi

ja ir jāiegust lielas nbīdes deformācijas, izmanto plānu slāņu gumijas -metāla elementus, kuru augstums ir daudz lielāks par pamata izmēru. Šādam elementam darbojoties zem liela spiediena, notiek vidējo elementu slāņu izspiešana jeb gareņstabilitātes zaudējums, kas rada nekontrolējamu slāņu nobīdi

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

Elastomēra amortizatora stinguma aprēķins, ņemot vērā tā starpslāņa deformāciju

Darbā apskatīta stinguma raksturojuma „spēks - nosēde” iegūšanas metodika plāno slāņu elastomēra amortizatoriem, kas strādā uz stiepi-spiedi, ievērojot neelastomēra slāņu deformācijas. Ir paradīts, ka neelastomēru slāņu deformācijas neievērošana var radīt nozīmīgas kļūdas izstrādājumu nosēdes aprēķināšanā. Pielietota lineārās stinguma teorijas variācijas metode vāji saspiežamiem materiāliem. Uzdevumu risinām ar variācijas metodi, pielietojot potenciālās enerģijas minimuma principu vāji saspiežamiem materiāliem. Šajā darbā piedāvāts viens no aprēķina shēmas variantiem, kurš ļauj novērtēt neelastomēra slāņa deformācijas ietekmi uz izstrādājumu stinguma raksturojumiem pie stiepes un spiedes mazo deformāciju apgabalā. Iegūtās analītiskās atkarības rekomendē pielietot kompensējošo daudzslāņu izstrādājumu projektēšanā