scholarly journals The Surge Problem as Related to the ASME Compressor Test Code PTC 10-1949

1960 ◽  
Author(s):  
Joseph T. Hamrick
Keyword(s):  
Reynolds Number ◽  
Common Ground ◽  
Axial Flow ◽  
Rotating Stall ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Axial Compressors ◽  
The Past ◽  
Rotating Blade ◽  
Aerodynamic Instability

Over the past decade a large amount of information has been accumulated on both centrifugal and axial compressors as a result of extensive research and development for gas turbine engines for aircraft. With the accumulation of this information it is important that a review be made of the ASME Power Test Code 10 for Centrifugal, Mixed-Flow and Axial Flow Compressors and Exhausters. As a result a committee has been appointed to revise ASME PTC 10 and bring it up to date. It is desirable as a part of this revised test code to include information on the problem of surging in compressors. Surging normally is defined as backflow which expresses itself both audibly and in violent instrument fluctuation. It is probable that the term surge should be extended to include any destructive forces that result from aerodynamic instability within the machine. If this is done, the problem of detection becomes more acute. For example, instabilities in both axial flow and centrifugal compressors which were not audible have resulted in failures. Rotating stall which has been reported in a number of papers has been investigated in both rotating blade rows and in stationary cascades. It is not the purpose of this paper to rehash the problem of rotating stall. Rather, it is intended here to discuss what aspects of aerodynamic instability should be considered by the user and the manufacturer and what common ground in compressor specifications can be met. It is recognized that although the compressor is normally the source of aerodynamic instabilities, these can be magnified by system arrangement. Therefore a compressor that operates quite satisfactorily in one system may fail in another. One of the main problems that is encountered in aerodynamic instability occurs with shifts in Reynolds number. Frequently the effects of Reynolds number change can be detected by running complete compressor maps over a range of inlet pressures. This in itself may require more testing than generally is expected by the supplier or the user. Therefore it is a second purpose of this discussion to emphasize the importance of thorough compressor test programs.

Method for Operational Diagnostics of the Prepumping State of Gas Turbine Engines Based on Invariants of Acoustic Processes

NDT World ◽  
2021 ◽  
pp. 58-61
Author(s):  
Aleksey Popov ◽  
Aleksandr Romanov
Keyword(s):  
Gas Turbine ◽  
Acoustic Signal ◽  
Acoustic Method ◽  
Random Processes ◽  
Rotating Stall ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Turbine Engine ◽  
Software Complex ◽  
Operational Diagnostics

A large number of aviation events are associated with the surge of gas turbine engines. The article analyzes the existing systems for diagnostics of the surge of gas turbine engines. An analysis of the acoustic signal of a properly operating gas turbine engine was carried out, at which a close theoretical distribution of random values was determined, which corresponds to the studied distribution of the amplitudes of the acoustic signal. An invariant has been developed that makes it possible to evaluate the development of rotating stall when analyzing the acoustic signal of gas turbine engines. A method is proposed for diagnosing the pre-surge state of gas turbine engines, which is based on processing an acoustic signal using invariant dependencies for random processes. A hardware-software complex has been developed using the developed acoustic method for diagnosing the pre-surge state of gas turbine engines.

Improved criteria for stall-free preliminary design of axial compressor of aero gas turbine engines

2018 ◽  
Vol 233 (9) ◽  
pp. 3286-3297 ◽  
Author(s):  
MR Aligoodarz ◽  
A Mehrpanahi ◽  
M Moshtaghzadeh ◽  
A Hashiehbaf
Keyword(s):  
Gas Turbine ◽  
Large Scale ◽  
Axial Compressor ◽  
Axial Flow ◽  
Design Criterion ◽  
Flow Coefficient ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Parameter Ranges ◽  
Axial Flow Compressors

A worldwide effort has been devoted to developing highly efficient and reliable gas turbine engines. There exist many prominent factors in the development of these engines. One of the most important features of the optimal design of axial flow compressors is satisfying the allowable range for various parameters such as flow coefficient, stage loading, the degree of reaction, De-Haller number, etc. But, there are some applicable cases that the mentioned criteria are exceeded. One of the most famous parameters is De-Haller number, which according to literature data should not be kept less than 0.72 in any stage of the axial compressor. A deep insight into the current small- or large-scale axial flow compressors shows that a discrepancy will occur among design criterion for De-Haller number and experimental measurements in which the De-Haller number is less than the design limit but no stall or surge is observed. In this paper, an improved formulation is derived based on one-dimensional modeling for predicting the stall-free design parameter ranges especially stage loading, flow coefficient, etc. for various combinations. It was found that the current criterion is much more accurate than the De-Haller criterion for design purposes.

Validation of steady and unsteady CFD strategies in the design of axial compressors for gas turbine engines

2020 ◽  
Vol 107 ◽  
pp. 106307
Author(s):  
Corrado Burberi ◽  
Vittorio Michelassi ◽  
Alberto Scotti del Greco ◽  
Salvatore Lorusso ◽  
Libero Tapinassi ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Axial Compressors

Inlet Fogging of Gas Turbine Engines: Part B — Fog Droplet Sizing Analysis, Nozzle Types, Measurement and Testing

2002 ◽  
Author(s):  
Mustapha Chaker ◽  
Cyrus B. Meher-Homji ◽  
Thomas Mee
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Measurement Techniques ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Size Measurement ◽  
The Past ◽  
Testing Method ◽  
Measurement And Testing ◽  
Experimental And Theoretical Studies

The inlet fogging of gas turbine engines for power augmentation has seen increasing application over the past decade yet not a single technical paper treating the physics and engineering of the fogging process, droplet size measurement, droplet kinetics, or the duct behavior of droplets, from a gas turbine perspective, is available. This paper provides the results of extensive experimental and theoretical studies conducted over several years, coupled with practical aspects learned in the implementation of nearly 500 inlet fogging systems on gas turbines ranging in power from 5 to 250 MW. Part B of the paper treats the practical aspects of fog nozzle droplet sizing, measurement and testing presenting the information from a gas turbine fogging perspective. This paper describes the different measurement techniques available, covers design aspects of nozzles, provides experimental data on different nozzles and provides recommendations for a standardized nozzle testing method for gas turbine inlet air fogging.

The Measurement and Interpretation of Flow within Rotating Stall Cells in Axial Compressors

1978 ◽  
Vol 20 (2) ◽  
pp. 101-114 ◽  
Author(s):  
I. J. Day ◽  
N.A. Cumpsty
Keyword(s):  
Flow Direction ◽  
Axial Flow ◽  
Tangential Direction ◽  
Rotating Stall ◽  
Design Flow ◽  
Flow Measurements ◽  
Axial Compressors ◽  
Multi Stage ◽  
Wide Range ◽  
Flow Compressor

Detailed flow measurements obtained by a new measuring technique are presented for the flow in a stalled axial-flow compressor. Results were obtained from a wide range of compressor builds, including multi-stage and single-stage configurations of various design flow rates and degrees of reaction. Instantaneous recordings of absolute velocity, flow direction and total and static pressures have been included for both full-span and part-span stall. With the aid of these results, it has been shown that the conventional model of the flow in a stall cell is erroneous. An alternative model is proposed, based on the observation that the fluid must cross from one side of the cell to the other in order to preserve continuity in the tangential direction. An investigation of the experimental results also reveals the finer details of the flow in the cell and shows how these details are related to the design flow rate of the compressor. The influence of these cell details on the power absorbed by a stalled compressor are investigated, and consideration is given to the complex pressure patterns encountered in the compressor.

scholarly journals EFFECT OF HYSTERESIS IN AXIAL COMPRESSORS OF GAS-TURBINE ENGINES

Aviation ◽  
2012 ◽  
Vol 16 (4) ◽  
pp. 97-102 ◽  
Author(s):  
Mykola Kulyk ◽  
Ivan Lastivka ◽  
Yuri Tereshchenko
Keyword(s):  
Gas Turbine ◽  
Axial Compressor ◽  
Separated Flow ◽  
Aerodynamic Performance ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Bladed Disks ◽  
Axial Compressors

The phenomenon of separated flow hysteresis in the process of the streamlining the axial compressor of gas-turbine engines is considered. Generalised results of research on the occurrence of hysteresis in the aerodynamic performance of compressor grids and its influence on the performance of the bladed disks of compressors that operate in real conditions of periodic circular non-uniformity are demonstrated.

scholarly journals Simulation of Gas Turbine Engines Considering the Rotating Stall in a Compressor

2017 ◽  
Vol 176 ◽  
pp. 207-217 ◽  
Author(s):  
A.E. Mikhailov ◽  
A.B. Mikhailova ◽  
Yu.M. Akhmetov ◽  
D.A. Akhmedzyanov
Keyword(s):  
Gas Turbine ◽  
Rotating Stall ◽  
Turbine Engines ◽  
Gas Turbine Engines

Fault Diagnosis in Gas Turbines Using a Model-Based Technique

1993 ◽  
Author(s):  
Graeme L. Merrington
Keyword(s):  
Gas Turbines ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Physical Processes ◽  
Important Conclusion ◽  
Large Power ◽  
The Past ◽  
Model Based ◽  
Dynamic Components ◽  
Reliable Methods

Reliable methods for diagnosing faults and detecting degraded performance in gas turbine engines are continually being sought. In this paper, a model-based technique is applied to the problem of detecting degraded performance in a military turbofan engine from take-off acceleration type transients. In the past, difficulty has been experienced in isolating effects of some of the physical processes involved. One such effect is the influence of the bulk metal temperature on the measured engine parameters during large power excursions. It will be shown that the model-based technique provides a simple and convenient way of separating this effect from the faster dynamic components. The important conclusion from this work is that good fault coverage can be gleaned from the resultant pseudo steady-state gain estimates derived in this way.

A Mean Line Prediction Method for Axial Flow Turbine Efficiency

1982 ◽  
Vol 104 (1) ◽  
pp. 111-119 ◽  
Author(s):  
S. C. Kacker ◽  
U. Okapuu
Keyword(s):  
Gas Turbine ◽  
Axial Flow ◽  
Prediction Method ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Loss System ◽  
Turbine Efficiency ◽  
Wide Range ◽  
Line Loss ◽  
Axial Turbines

A mean line loss system is described, capable of predicting the design point efficiencies of current axial turbines of gas turbine engines. This loss system is a development of the Ainley/Mathieson technique of 1951. The prediction method is tested against the “Smith’s chart” and against the known efficiencies of 33 turbines of recent design. It is shown to be able to predict the efficiencies of a wide range of axial turbines of conventional stage loadings to within ± 1 1/2 percent.

Inlet Fogging of Gas Turbine Engines: Experimental and Analytical Investigations on Impaction Pin Fog Nozzle Behavior

2006 ◽  
Vol 128 (4) ◽  
pp. 826-839 ◽  
Author(s):  
Mustapha A. Chaker ◽  
Cyrus B. Meher-Homji ◽  
Thomas Mee
Keyword(s):  
Gas Turbine ◽  
Evaporation Rate ◽  
Climatic Conditions ◽  
Turbine Engines ◽  
Theoretical Studies ◽  
Gas Turbine Engines ◽  
The Past ◽  
The Subject ◽  
Evaporation Dynamics ◽  
Experimental And Theoretical Studies

The inlet fogging of gas turbine engines for power augmentation has seen increasing application over the past decade. This paper provides the results of extensive experimental and theoretical studies conducted on impaction pin fog nozzles. It covers the important area of the fog plume pattern of impaction pin nozzles and examines fog-plume uniformity. The subject of sprinkle (large droplet formation) from the nozzles is also examined in detail and is shown to be nonsignificant. The effect, on evaporation rate, of ambient climatic conditions and the location of the fog nozzle with respect to the gas turbine inlet duct has been analytically and experimentally analyzed. An analytical model is used to study the evaporation dynamics of fog droplets injected in the inlet ducts. The model is validated experimentally in a wind tunnel.

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