Eng
Eng
RusNumerical simulation of turbulent jet flows using the high resolution RANS/ILES method
The results of jet flows simulations at subsonic and supersonic jet velocities are considered. The effect of operating parameters (temperature and nozzle pressure ratio) on the jet flow characteristics is considered. The expansion of a subsonic jet, including in the presence of chevrons and a cocurrent flow, has been studied. Supersonic jets are considered in formulations with a rectangular nozzle, an axisymmetric biconical nozzle and an airfield. Numerical studies are carried out using the high-resolution RANS/ILES method.
Keywords: RANS/ILES method, turbulence jet flows
Benderskiy L.A., Lyubimov D.A.
Investigation of the aircraft engine dynamics in case of fan blade-out
The paper presents a simple and efficient approach to modeling unbalanced rotor dynamics. The proposed method makes it possible to take into account rotor-casing contact interaction through flexible blade row and changes in the rotor rotational speed due to contact and aerodynamic forces. Nonlinear model of the aircraft engine is constructed. The model includes all components of the engine’s structural frame. Engine dynamic behavior in case of fan blade-out is investigated. Load reduction device efficiency and contact interactions influence on the system dynamics are studied.
Keywords: fan blade-out, rotordynamics, unbalance, load reduction device, rotor-casing contact interaction
Myasnikov V.Yu.
The problem of noise in promising turbofan engines for long-haul aircraft
One of the tasks for the domestic aircraft engine industry is the development and creation of competitive engines in the thrust range of 250…450?kN for twin aisle aircraft. A comparative assessment of the noise levels of twin aisle aircraft equipped by two turbofans with direct drive or geared drive is presented. The main directions of research in creation new technologies for reducing noise sources of advanced turbofan engines are outlined.
Keywords: aircraft noise, engine noise sources, jet, fan, combustor, turbine, hush kit, sound-absorbing liner, fan direct drive, fan gear drive
Evstigneev A.A., Lanshin A.I., Pochkin Ia.S., Solonin V.I., Khaletskii Iu.D.
Joining of ceramic parts and structures in the hot duct of gas turbine engine on the experience of the oversees aeroengine companies (review)
The main problems related to joining of ceramic parts and units in the hot duct of a gas turbine engine (GTE) are examined based on the experience of foreign aeroengine companies. Possible reasons of the thermally induced stresses in ceramic materials are highlighted: different values of the coefficient of linear thermal expansion (CLTE) of metal and ceramic structural elements, different pressure on face and backside surfaces of parts and units, non-uniform temperature distribution on the surfaces of parts and units. It was shown that the dissimilar materials are frequently joined using flexible metal attachments, which may reduce differences in CLTE. Additionally, the use of special flexible fibrous materials is recommended to eliminate bonding between ceramic and metal parts and units. Special metallic fasteners which reduce severe thermal stresses for «metal-ceramic» pairs at elevated temperatures are also widely used.
Keywords: joining, coefficient of thermal expansion, ceramic GTE, combustor
Sorokin O.Yu., Chainikova A.S., Kuznetsov B.Yu., Volobueva T.M., Vaganova M.L.
On the assessment of a high-speed passenger aircraft’s average level of comfortable g-force
Based on aviation medicine and flight performance data from high-speed passenger aircraft projects, an assessment of g-force during acceleration was conducted to ensure a comfortable flight for passengers.
Keywords: high-speed passenger aircraft, supersonic passenger aircraft, acceleration, g-force, comfortable flight conditions
Shlyakotin V.E.
International experience in research and application of the technological process of laser shock peening of metals (review)
This study describes physics and classification of technological processes of laser shock peening (LSP), areas of application of LSP in the aviation industry, main results of theoretical and experimental studies of LSP carried out in recent years, and mathematical models of LSP.
Keywords: laser shock peening, surface hardening, residual stress, plasma, fatigue, foreign object damage, mathematical model, unsteady problem, explicit dynamics, implicit dynamics, eigenstrain
Novikov I.A., Nozhnitsky Yu.A., Shibaev S.A.
New technologies for reducing harmful emissions and CO2 in combustion products of GTU and GTE through mixing and gradual transition to hydrogen fuel
There is a growing interest in using hydrogen as fuel for gas turbine engines as a way to reduce emissions of harmful substances and generate more “clean” electricity. However, the transition from traditional fuel to alternative fuel should occur without compromising the efficiency of combustion. Adaptation to hydrogen while solving operational problems is the main subject of interest in the development of GTE combustion chambers with a low level of emissions of harmful substances. Changes in chemical and physical properties of fuel affect the overall design of the combustion system, complicating it, which requires extensive testing. The article summarizes CIAM’s experience of using cryogenic fuels: hydrogen and liquefied natural gas, and also considers problems of the combustion chamber’s operability caused by chemical kinetics of hydrogen, including self-ignition, instability and flame flashback.
Keywords: combustion chamber, emission, emissions of harmful substances, alternative fuel, cryogenic fuel, hydrogen, liquefied natural gas, sustainable combustion
Vladimirov A.V., Sverdlov E.D., Dubovitsky A.N.