scholarly journals Dependence of thermogasodynamic parameters of operation of a helicopter gas turbine engine on its operation and dust in the atmosphere

Author(s):  
V. A. Potapov ◽  
A. A. Sanko ◽  
M. V. Kudin

By scanning the blades of the impeller and the guide devices of the full-scale compressor of the helicopter gas turbine engine, a solid-state design model of the compressor with a tunable geometry in the height of the blades was developed. The empirical dependencies of the values of nonlinear wear of the blade of the 1st stage of the compressor on the operating time and the concentration of dust in the air are presented. A block diagram of the procedure for calculating the characteristics and parameters of a helicopter gas turbine compressor is presented. When calculating the flow in the gas–air path of the compressor, the numerical solution of the Navier–Stokes equations averaged by Reynolds, the finite element method in combination with the establishment of patterns of erosive wear of the blades depending on the operating conditions of the engine is used. Mathematical dependencies of the thermogasodynamic parameters of the helicopter gas turbine compressor operation on its operating time and the dustiness of the atmosphere are obtained using modeling. The obtained results can be used in the development of a methodology for automated monitoring of the wear condition of the compressor blades of a helicopter gas turbine engine according to its thermogasodynamic parameters, applied to various climatic operating conditions.

2020 ◽  
Vol 23 (5) ◽  
pp. 39-53
Author(s):  
V. A. Potapov ◽  
A. A. Sanko

The construction and useful practice of gas-turbine engine diagnosis systems depend largely on the availability of the engine mathematical models and its certain components in their structure. Utilization of multi-stage axial flow compressor performance with account for erosive wear of its parts during the operation fundamentally raises possibilities of such systems as erosive wear of flow channel, blade rings of impellers and vane rings of multi-stage compressor is a common cause of preschedule gas-turbine engine detaching from an aircraft. As evidenced by various contributions presented in the article, special emphasis on abrasive wear impact assessment on axial flow compressor performance is placed upon rotor-wing turbo-shaft engine due to their particular operating conditions. One of the main tasks in the process of mathematic simulation of an axial flow compressor blade ring is consideration of its wear type that again has a nonlinear distribution along the level of the blade. In addition, wear rate at entry and exit blade edges often have different principles. Detecting of these principles and their consideration when constructing the compressor mathematical model is a crucial task in diagnostic assessment and integrity monitoring of rotor-wing turbo-shaft engine in operation. The article represents a concept to an estimate nonlinear erosive wear effect of axial flow compressor blades on its performance based on the three-dimensional flow approach in the gas-air flow duct of compressor with a formulation of the blade rings. This approach renders possible to take into account the nonlinearity of the compressor blades wear during their operation. Through the example of the inlet compressor stage of a rotor-wing aircraft gas-turbine engine, the engine pump properties predictions with different kind of rotor blade wear have been presented.


1981 ◽  
Vol 13 (4) ◽  
pp. 401-407 ◽  
Author(s):  
V. T. Troshchenko ◽  
A. V. Prokopenko ◽  
V. N. Torgov ◽  
M. V. Baumshtein ◽  
L. B. Getsov

Author(s):  
Sean G. Leithead ◽  
William D. E. Allan ◽  
Linruo Zhao ◽  
Qi Yang

Performance differences between bare 17-4PH steel V103 profile (NACA 6505 with rounded leading edge (LE) and trailing edge (TE)) gas turbine engine axial compressor blades, and those coated with either a chromium-aluminum-titanium nitride (CrAlTiN) or a titanium-aluminum nitride (TixAl1−xN) erosion-resistant coating were tested. A coating thickness of 16 μm was used, based on experimental results in the literature. Coatings were applied using arc physical vapor deposition at the National Research Council of Canada (NRC). All blades were tested under identical operating conditions in the Royal Military College of Canada (RMC) turbomachinery erosion rig. Based on a realism factor (RF) defined by the authors, this experimental rig was determined to provide the best known approximation to actual compressor blade erosion in aircraft gas turbine engine axial compressors. An average brown-out erosive media concentration of 4.9 g/m3 of air was used during testing. An overall defined Leithead–Allan–Zhao (LAZ) score metric, based on mass and blade dimension changes, compared the erosion-resistant performance of the bare and coated blades. Blade surface roughness data were also obtained. Based on the LAZ Score, CrAlTiN-coated blades performed at least 79% better than bare blades, and TixAl1−xN-coated blades performed at least 93% better than bare blades. The TixAl1−xN-coated blades performed at least 33% better than the CrAlTiN-coated blades. Extrapolation of results predicted that a V-22 Osprey tiltrotor military aircraft, for example, could fly up to 79 more missions with TixAl1−xN-coated compressor blades in brown-out sand concentrations than with uncoated blades.


2021 ◽  
Vol 316 ◽  
pp. 868-872
Author(s):  
Maksim A. Orlov ◽  
Irina A. Polikarpova ◽  
Aleksander N. Kalinnikov

The article presents testing of polymer protective coating based on polyurethane developed in Bauman Moscow State Technical University. It is shown that the developed coating has an increased resistance to erosive wear, an increased level of adhesion and temperature resistance, compared with the existing coatings, certified by aviation.


1992 ◽  
Vol 114 (4) ◽  
pp. 763-767 ◽  
Author(s):  
J. W. Watts ◽  
T. E. Dwan ◽  
C. G. Brockus

An analog fuel control for a gas turbine engine was compared with several state-space derived fuel controls. A single-spool, simple cycle gas turbine engine was modeled using ACSL (high level simulation language based on FORTRAN). The model included an analog fuel control representative of existing commercial fuel controls. The ACSL model was stripped of nonessential states to produce an eight-state linear state-space model of the engine. The A, B, and C matrices, derived from rated operating conditions, were used to obtain feedback control gains by the following methods: (1) state feedback; (2) LQR theory; (3) Bellman method; and (4) polygonal search. An off-load transient followed by an on-load transient was run for each of these fuel controls. The transient curves obtained were used to compare the state-space fuel controls with the analog fuel control. The state-space fuel controls did better than the analog control.


Author(s):  
Godwin Ita Ekong ◽  
Christopher A. Long ◽  
Peter R. N. Childs

Compressor tip clearance for a gas turbine engine application is the radial gap between the stationary compressor casing and the rotating blades. The gap varies significantly during different operating conditions of the engine due to centrifugal forces on the rotor and differential thermal expansions in the discs and casing. The tip clearance in the axial flow compressor of modern commercial civil aero-engines is of significance in terms of both mechanical integrity and performance. In general, the clearance is of critical importance to civil airline operators and their customers alike because as the clearance between the compressor blade tips and the casing increases, the aerodynamic efficiency will decrease and therefore the specific fuel consumption and operating costs will increase. This paper reports on the development of a range of concepts and their evaluation for the reduction and control of tip clearance in H.P. compressors using an enhanced heat transfer coefficient approach. This would lead to improvement in cruise tip clearances. A test facility has been developed for the study at the University of Sussex, incorporating a rotor and an inner shaft scaled down from a Rolls-Royce Trent aero-engine to a ratio of 0.7:1 with a rotational speed of up to 10000 rpm. The idle and maximum take-off conditions in the square cycle correspond to in-cavity rotational Reynolds numbers of 3.1×106 ≤ Reφ ≤ 1.0×107. The project involved modelling of the experimental facilities, to demonstrate proof of concept. The analysis shows that increasing the thermal response of the high pressure compressor (HPC) drum of a gas turbine engine assembly will reduce the drum time constant, thereby reducing the re-slam characteristics of the drum causing a reduction in the cold build clearance (CBC), and hence the reduction in cruise clearance. A further reduction can be achieved by introducing radial inflow into the drum cavity to further increase the disc heat transfer coefficient in the cavity; hence a further reduction in disc drum time constant.


In the past three decades, it is very challenging for the researchers to design and development a best gas turbine engine component. Engine component has to face different operating conditions at different working environments. Nickel based superalloys are the best material to design turbine components. Inconel 718, Inconel 617, Hastelloy, Monel and Udimet are the common material used for turbine components. Directional solidification is one of the conventional casting routes followed to develop turbine blades. It is also reported that the raw materials are heat treated / age hardened to enrich the desired properties of the material implementation. Accordingly they are highly susceptible to mechanical and thermal stresses while operating. The hot section of the turbine components will experience repeated thermal stress. The halides in the combination of sulfur, chlorides and vanadate are deposited as molten salt on the surface of the turbine blade. On prolonged exposure the surface of the turbine blade starts to peel as an oxide scale. Microscopic images are the supportive results to compare the surface morphology after complete oxidation / corrosion studies. The spectroscopic results are useful to identify the elemental analysis over oxides formed. The predominant oxides observed are NiO, Cr2O3, Fe2O3 and NiCr2O4. These oxides are vulnerable on prolonged exposure and according to PB ratio the passivation are very less. In recent research, the invention on nickel based superalloys turbine blades produced through other advanced manufacturing process is also compared. A summary was made through comparing the conventional material and advanced materials performance of turbine blade material for high temperature performance.


Author(s):  
S.M. Sergeev ◽  
◽  
V.A. Kudriashov ◽  
N.V. Petrukhin ◽  
◽  
...  

The main technical characteristics of jet engines depend on the fuel quality: thrust and fuel consumption. As a rule, the comparative assessment of real engines is carried by specific values. Specific thrust is one of the most important parameters of the gas turbine engine (GTE). The larger it is, the smaller the required air flow rate through the engine at a given thrust and therefore its dimensions and mass. To date, a system for evaluating the performance properties of fuels based on qualification methods has been created. However, these methods do not allow calculating the thrust and specific thrust of the engine and potentially assessing the effect of fuels on these characteristics. Therefore, the issues of efficient use of fuels for GTE are solved almost exclusively on the basis of tests at testing units with full-scale engines, which are carried out repeatedly, which leads to a significant increase in the cost of testing. The article proposes a method for calculating the thrust and specific thrust of a double-flow gas turbine engine according to the results of tests at a constant volume laboratory unit of bypass type “Flame”. The method is based on modeling the engine operating conditions using the similarity criteria of the bench reactor and the real engine and allows reducing significantly the material and time costs for testing. The experimental of the combustion characteristics of hydrocarbon fuels and the rated values of their thrust and specific thrust for a double-flow gas turbine engine are presented.


Author(s):  
Jeffrey Schutte ◽  
Jimmy Tai ◽  
Jonathan Sands ◽  
Dimitri Mavris

The focus of this study is to compare the aerothermodynamic cycle design space of a gas turbine engine generated using two on-design approaches. The traditional approach uses a single design point (SDP) for on-design cycle analysis, where off-design cycle analysis must be performed at other operating conditions of interest. A multi-design point (MDP) method performs on-design cycle analysis at all operating conditions where performance requirements are specified. Effects on the topography of the cycle design space as well as the feasibility of the space are examined. The impacts that performance requirements and cycle assumptions have on the bounds and topography of the feasible space are investigated. The deficiencies of a SDP method in determining an optimum gas turbine engine will be shown for a given set of requirements. Analysis will demonstrate that the MDP method, unlike the SDP method, always obtains a properly sized engine for a set of given requirements and cycle design variables, resulting in an increased feasible region of the aerothermodynamic cycle design space from which the optimum performance engine can be obtained.


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