Understanding Unsteady Flow Behaviour in a Low Aspect Ratio Contra-Rotating Axial Fan Under Radially Distorted Inflow

2019 ◽  
Author(s):  
Manas Madasseri Payyappalli ◽  
A. M. Pradeep
Keyword(s):  
Aspect Ratio ◽  
Unsteady Flow ◽  
Gas Turbine ◽  
Pressure Sensors ◽  
Pressure Rise ◽  
Wire Mesh ◽  
Turbine Engines ◽  
Length Scale ◽  
Gas Turbine Engines ◽  
Low Aspect Ratio

Abstract Contra-rotation has several advantages like swirl-free discharge, high pressure-rise per stage, and possibility of operating both the rotors at different speeds. With these merits, contra-rotating fan emerges as a competent technology for future gas turbine engines. During operation, gas turbine engines undergo situations like high angle of attack manoeuvres, large cross-winds, bird-hits, etc. which distort the flow at the inlet of the engine. A thorough understanding of the effect of distortion on low aspect ratio contra-rotating fans is missing in literature. This paper reports the consequences of radial distortion on the performance of a low aspect ratio contra-rotating fan. The uniform inlet flow is distorted radially using wire mesh screens. The unsteady data obtained from high response pressure sensors are analysed using Discrete Spatial Fourier Series (DSFS) and Morlet wavelet transform. Both Long Length Scale Disturbances (LLSD) or modal waves and Short Length Scale Disturbances (SLSD) or spikes are observed for different inflow conditions. The stage stalls primarily due to the instabilities arising at the tip region of rotor-1. Rotor-2 shows poor coherence in the disturbances prior to stall compared to that of rotor-1. Tip-distorted flow is dominated with SLSDs in the pre-stall region and hence a stall precursor is not observed whereas clean and hub-distorted flows show prominent LLSDs prior to stall. The radial distortions get redistributed at the exit of rotor-1 and hence, the distorted inflows do not severely lead to instabilities on rotor-2. In summary, this work explains in detail the development of unsteady flow phenomena occurring in a low-aspect ratio contra-rotating fan stage leading to stall and the way in which the system responds to it.

High Intensity, Large Length-Scale Freestream Turbulence Generation in a Transonic Turbine Cascade

2002 ◽  
Author(s):  
A. C. Nix ◽  
A. C. Smith ◽  
T. E. Diller ◽  
W. F. Ng ◽  
K. A. Thole
Keyword(s):  
Heat Transfer ◽  
Gas Turbine ◽  
High Intensity ◽  
Turbine Engines ◽  
Length Scale ◽  
Gas Turbine Engines ◽  
Freestream Turbulence ◽  
Large Length ◽  
Scale Turbulence ◽  
Large Length Scale

Heat transfer predictions in gas turbine engines have focused on cooling techniques and on the effects of various flow phenomena. The effects of wakes, passing shock waves and freestream turbulence have all been of primary interest to researchers. The focus of the work presented in this paper is to develop a turbulence grid capable of generating high intensity, large-scale turbulence for use in experimental heat transfer measurements in a transonic facility. The grid is desired to produce freestream turbulence characteristic of the flow exiting the combustor of advanced gas turbine engines. A number of techniques are discussed in this paper to generate high intensity, large length-scale turbulence for a transonic facility. Ultimately, the passive grid design chosen is capable of producing freestream turbulence with intensity of approximately 10–12% near the entrance of the cascade passages with an integral length-scale of 2 cm.

Gas Screen in Components of Gas Turbine Engines

1997 ◽  
Vol 28 (7-8) ◽  
pp. 536-542
Author(s):  
A. A. Khalatov ◽  
I. S. Varganov
Keyword(s):  
Gas Turbine ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Gas Screen

Potential Application of Composite Materials to Future Gas Turbine Engines

1988 ◽  
Author(s):  
James C. Birdsall ◽  
William J. Davies ◽  
Richard Dixon ◽  
Matthew J. Ivary ◽  
Gary A. Wigell
Keyword(s):  
Composite Materials ◽  
Gas Turbine ◽  
Potential Application ◽  
Turbine Engines ◽  
Gas Turbine Engines

Method of tribodiagnostics of d-30KU engines/KP with the use of a microwave plasma complex: results of metrological examination and analysis of the accuracy

2020 ◽  
pp. 22-29
Author(s):  
A. Bogoyavlenskiy ◽  
A. Bokov
Keyword(s):  
Gas Turbine ◽  
Microwave Plasma ◽  
Technical Condition ◽  
The State ◽  
Turbine Engines ◽  
Metrological Examination ◽  
Gas Turbine Engines ◽  
High Frequency Plasma ◽  
Frequency Plasma ◽  
Primary Standards

The article contains the results of the metrological examination and research of the accuracy indicators of a method for diagnosing aircraft gas turbine engines of the D30KU/KP family using an ultra-high-frequency plasma complex. The results of metrological examination of a complete set of regulatory documents related to the diagnostic methodology, and an analysis of the state of metrological support are provided as well. During the metrological examination, the traceability of a measuring instrument (diagnostics) – an ultrahigh-frequency plasma complex – is evaluated based on the scintillation analyzer SAM-DT-01–2. To achieve that, local verification schemes from the state primary standards of the corresponding types of measurements were built. The implementation of measures to eliminate inconsistencies identified during metrological examination allows to reduce to an acceptable level the metrological risks of adverse situations when carrying out aviation activities in industry and air transportation. In addition, the probability of occurrence of errors of the first and second kind in the technological processes of tribodiagnostics of aviation gas turbine engines is reduced when implementing a method that has passed metrological examination in real practice. At the same time, the error in determining ratings and wear indicators provides acceptable accuracy indicators and sufficient reliability in assessing the technical condition of friction units of the D-30KP/KP2/KU/KU-154 aircraft engines.

On the prospects of application of nanostructured heterophase polyfunctional composite materials inengine building industry

2019 ◽  
pp. 50-57
Author(s):  
O. B. Silchenko ◽  
M. V. Siluyanova ◽  
V. Е. Nizovtsev ◽  
D. A. Klimov ◽  
A. A. Kornilov
Keyword(s):  
Composite Materials ◽  
Gas Turbine ◽  
Developed Countries ◽  
The United States ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Nanostructured Composite ◽  
Polymer Metal ◽  
Long Operation ◽  
Prospects Of Application

The paper gives a brief review of properties and applications of developed extra-hard nanostructured composite materials and coatings based on them. The presentresearch suggestsaerospace applications of nanostructured composite materials based on carbides, carbonitrides and diboridesof transition and refractory metals. To improve the technical and economic performance of gas turbine engines, it is advisable to use new composite structural materials whose basic physicomechanical properties are several times superior to traditional ones. The greatest progress in developing new composites should be expected in the area of materials created on the basis of polymer, metal, intermetallic and ceramic matrices. Currently components and assemblies of gas turbine engines and multiple lighting power units with long operation life and durability will vigorously develop. Next-generation composites are studied in all developed countries, primarily in the United States and Japan.

scholarly journals Progress in Novel Electrodeposited Bond Coats for Thermal Barrier Coating Systems

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4214
Author(s):  
Kranthi Kumar Maniam ◽  
Shiladitya Paul
Keyword(s):  
Gas Turbine ◽  
Thermal Barrier Coating ◽  
Gas Turbines ◽  
High Performance ◽  
Turbine Engines ◽  
Thermal Barrier ◽  
Gas Turbine Engines ◽  
Potential Cost ◽  
Bond Coats ◽  
Barrier Coating

The increased demand for high performance gas turbine engines has resulted in a continuous search for new base materials and coatings. With the significant developments in nickel-based superalloys, the quest for developments related to thermal barrier coating (TBC) systems is increasing rapidly and is considered a key area of research. Of key importance are the processing routes that can provide the required coating properties when applied on engine components with complex shapes, such as turbine vanes, blades, etc. Despite significant research and development in the coating systems, the scope of electrodeposition as a potential alternative to the conventional methods of producing bond coats has only been realised to a limited extent. Additionally, their effectiveness in prolonging the alloys’ lifetime is not well understood. This review summarises the work on electrodeposition as a coating development method for application in high temperature alloys for gas turbine engines and discusses the progress in the coatings that combine electrodeposition and other processes to achieve desired bond coats. The overall aim of this review is to emphasise the role of electrodeposition as a potential cost-effective alternative to produce bond coats. Besides, the developments in the electrodeposition of aluminium from ionic liquids for potential applications in gas turbines and the nuclear sector, as well as cost considerations and future challenges, are reviewed with the crucial raw materials’ current and future savings scenarios in mind.

scholarly journals A method of air-blast atomization of foamed liquid fuels for advanced combustors of gas-turbine engines

2020 ◽  
Vol 1675 ◽  
pp. 012111
Author(s):  
A Yu Vasilyev ◽  
O G Chelebyan ◽  
A A Sviridenkov ◽  
E S Domrina ◽  
A A Loginova ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Liquid Fuels ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Air Blast
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