Wyniki wyszukiwania - Biblioteka Nauki

1

Approximation method of determining the analytical model of naval gas turbine axial compressor

100%

Korczewski Z. , Olejniczak K.

Polish Maritime Research

|

1999

|

tom nr 3

7-10

EN

The paper presents a way of determining the analytical model of an axial compressor on the basis of the least squares and polynomial, multimensional regression methods. The approach was applied to the axial compressors of DR77 engine and proved adequate. A satisfying consistence of the full--scale and model charateristics was obtained, hence usefulness of the method to modelling such object was confirmed.

2

Prognozowanie prędkości wzrostu pęknięć zmęczeniowych w dysku sprężarki osiowej

80%

Rozumek D. , Lachowicz C.

Czasopismo Techniczne. Mechanika

|

2006

|

tom R. 103, z. 1-M

309-317

PL

W artykule przedstawiono wyniki badań doświadczalnych wzrostu pęknięć zmęczeniowych na próbkach płaskich z karbem przy zginaniu. Materiał badany to stop tytanu Ti-6Al-4V, który jest szeroko stosowany na elementy maszyn, np. wirniki i łopatki turbin silników lotniczych, elementy konstrukcji nośnej, itp. Wymienione elementy konstrukcyjne pracują przeważnie w warunkach działania obciążeń zmęczeniowych. Badania prowadzone były przy obciążeniu z kontrolowaną siłą. Podczas badań wartość współczynnika asymetrii cyklu wynosiła R = 0. Wzrost pęknięć w dysku sprężarki osiowej turbiny lotniczej PW J52-P-8 modelowano metodą elementów brzegowych (MEB). Stwierdzono możliwość porównania prędkości wzrostu pęknięć uzyskaną z obliczeń numerycznych w dysku sprężarki z badaniami doświadczalnymi próbek.

EN

The paper presents fatigue crack growth rate test results for notched flat specimens under bending. The applied materials were titanium alloy Ti-6Al-4V, which is used for machines elements such as: aircraft engine rotors, fan blades of compressor disks and the various mechanical elements, etc. Those elements work often in conditions of fatigue loads. Test were done under control load and for the stress ratio R = 0. Crack growth in disk axial compressor aircraft engine turbine of the PW J52-P-8 is modeled using boundary element method. It has been found, that is possibility of comparison of crack growth rate was affirmed got in numerical calculations with results of specimens experimental tests.

3

Work parameters of the gas turbine engine during the change of flow passage geometry on the inlet of axial compressor

80%

Wirkowski P.

Journal of KONES

|

2009

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tom Vol. 16, No. 3

505-510

EN

The paper deals with the problem of influence of changes variable stator vanes axial compressor settings of gas turbine engine on work parameters of compressor and engine. Incorrect operation of change setting system of variable vanes could make unstable work of compressor and engine. This paper presents theoretical analysis of situation described above and results of own research done on real engine. When in the compressor construction is assembled system of setting change of variable stator vanes its task is to make optimal cooperation engine units during the permanent improvement of compressor characteristic. Perturbations in the operation of this system could cause changes in work of compressor and engine similarly as in the case of changes caused by changes of rotational speed or polluted interblades ducts of compressor. The purpose of investigations, which was carried out on real engine was determination influence of incorrect operation of axial compressor inlet guide variable stator vanes control system of gas turbine engine on compressor and engine work parameters. The object of research is type DR 77 marine gas turbine engine, which is aport of power transmission system of war ship. In compressor construction configuration of this engine there are used inlet guide stator vanes which make possibilities to change the setting angle incidence (change of compressor flow duet geometry) in depend on engine load. On the base of results of experiment there were determined the mathematical eguations modelling the changes of particular engine work parameters in the function of variable inlet guide stator vanes setting angle.

4

Influence Of Changes Of Axial Compressor Variable Stator Vanes Setting On Gas Turbine Engine Work

80%

Wirkowski P.

Journal of Polish CIMAC

|

2007

|

tom Vol. 2, no 2

511-517

EN

The paper deals with problem influence of changes settings variable stator vanes axial compressor of gas turbine engine on work parameters of compressor and engine. Incorrect operation of change setting system of variable vaness could make unstable work of compressor and engine. This situation is unacceptable because of mechanical overloads which could demage the engine. This paper presents theoretical analysis of situation described above and presents results of own researches done on real engine.

5

Numerical study of stall inception in a transonic axial compressor rotor based on the throttle model

80%

Zhu X. , Liu B. , Hu J. , Shen X.

Journal of Theoretical and Applied Mechanics

|

2015

|

tom Vol. 53 nr 2

307--316

EN

The goal of the current paper is to investigate inner flow behavior on stall inception in a transonic compressor rotor. The stall inception process is numerically carried out by unsteady 3-D simulations based on the throttle model. The current study shows that stall starts from the tip of the blade, and stall cell extends to the axial, circumferential and radial directions. Through the comparison of flow transition characteristics at different flow rate conditions, the interface between the incoming flow and tip clearance flow shifts forward to the upstream as the mass flow decreases. Eventually, the shock detaches from the blade leading edge, and tip clearance flow spills into the adjacent blade passage, thus stall happens in the affected blade passages.

6

Modelling the characteristics of axial compressor with variable stator vanes

80%

Wirkowski P.

Journal of KONES

|

2010

|

tom Vol. 17, No. 2

497-504

EN

One of the most important problems of exploitational use of marine gas turbine engine is knowledge about direction of changes realised unsteady processes. Individual dynamical features of each exploitated engine are determined on the way of costly experimental searches. These searches are qualifled by numerous constructional and exploitational confinements. In real exploitational conditions marine gasturbine engine works at different rotation speeds determined by the required parameters of ship's movement. Conversion from one rotation speed to another is related to realization of unsteady energetic processes, determined by the gasodynamic mutual influence of compressor configurations. The values of working medium flow thermodynamic parameters undergo significant changes in time. To work out the qualitative and quantitative estimation of these changes it is necessary to define the dynamic equations, describing working medium flow through the gas passage of engine. In the next step it is necessary to resohe the defined equations for disturbances of steady cooperation of compressor configurations. This paper concerns the application of mathematical modelling methods to analyzing gas-dynamic processes in marine gas turbines. The influence of geometry changes in axial compressor flow passage on kinematical air flow characteristics is presented. The elaborated mathematical model will make it possible to realize - in the future -simulative investigations of gas-dynamic processes taking place in a compressor fitted with controllable guide vanes.

7

Influence Of Axial Compressor Flow Passage Geometry Changes On Gas Turbine Engine Work Parameters

80%

Wirkowski P.

Journal of Polish CIMAC

|

2009

|

tom Vol. 4, no 2

307-313

EN

The paper deals with the problem of influence of changes variable stator vanes axial compressor settings of gas turbine engine on work parameters of compressor and engine. Incorrect operation of change setting system of variable vanes could make unstable work of compressor and engine. This paper presents theoretical analysis of situation described above and results of own research done on real engine. On the base of results of experiment there were determined mathematical equations determining relationships of changes of particular engine work parameters in function of variable inlet guide stator vanes setting angle. There are presented results of the solution of mathematical equations, which describe the changes of engine work parameters values too.

8

Multiple spike stall cells in low speed axial compressor rotor blade row

80%

Taghavi-Zenouz R. , Abbasi S.

Journal of Theoretical and Applied Mechanics

|

2015

|

tom Vol. 53 nr 1

47--57

EN

Inception and development of multiple stall cells of short length scales are numerically investigated in an axial compressor rotor blade row. The method of investigation is based on time accurate three-dimensional full annulus simulations. Time dependent flow structure results revealed that there are two criteria responsible for inception of a special kind of stall, introduced as spike stall in the literature. These criteria are defined as leading edge spillage and trailing edge backflow, which occur at specific mass flow rates near to stall conditions. The numerical results revealed that once the spike stall cells appear, they cover roughly two blade passages in the circumferential direction and cover about 25% of the blade height. By further revolution of the blade row, the number of cells tends to increase. For the present case study, the number of stall cells increased to three after 8.5 rotor revolutions from the moment of the initial spike stall occurrence. Even at this moment, both of the above mentioned criteria for the spike stall inception have been observed within the blades passages. These events caused the inlet relative flow angle to the blade rows, and therefore the flow incidence angle and consequent blockage to the main flow, to increase. The tip leakage flow frequency spectrum has been studied through surveying instantaneous static pressure signals imposed on pressure side of the blades and also on the casing walls. These latter results showed that any further revolving of the rotor blade row, exceeding 8.5 revolutions, causes the spike stall to disturb the flow structure significantly.

9

Influence of the incorrect settings of axial compressor inlet variable stator vanes on gas turbine engine work parameters

80%

Wirkowski P.

Journal of KONES

|

2012

|

tom Vol. 19, No. 3

483-489

EN

The paper deals with the problem of influence of changes variable stator vanes axial compressor settings of gas turbine engine on work parameters of compressor and engine. Incorrect operation of change setting system of variable vanes could make unstable work of compressor and engine. This paper presents theoretical analysis of situation described above and results of own research done on real engine. When in the compressor construction there is assembled system of setting change of variable stator vanes its task is to make optimal cooperation engine units during the permanent improvement of compressor characteristic. Perturbations in the operation of this system could cause changes in work of compressor and engine similarly as in the case of changes caused by changes of rotational speed or polluted interblades ducts of compressor. The purpose of investigations, which was carried out on real engine was determination influence of incorrect operation of axial compressor inlet guide variable stator vanes control system of gas turbine engine on compressor and engine work parameters. The object of research is type DR 77 marine gas turbine engine, which is a part of power transmission system of war ship. In compressor construction configuration of this engine there are used inlet guide stator vanes which make possibilities to change the setting angle incidance (change of compressor flow duct geometry) in depend on engine load. On the base of results of experiment there were determined the mathematical equations modelling the changes of particular engine work parameters in the function of variable inlet guide stator vanes setting angle.

10

Research Of Variation Of Gas Turbine Engine Work Parameters Changes Equipped With Changeable Geometry Of Axial Compressor Flow Passage

80%

Wirkowski P.

Journal of Polish CIMAC

|

2008

|

tom Vol. 3, no 1

9-13

EN

The paper deals with problem influence of changes variable stator vanes axial compressor settings of gas turbine engine on work parameters of compressor and engine. Incorrect operation of change setting system of variable vanes could make unstable work of compressor and engine. This paper presents theoretical analysis of situation described above and results of own research done on real engine. The next there are presented results of mathematical modelling of changes of gas turbine engine work parameters during change of angle setting of axial compressor variable stator vanes but in the most wide angle range than in real research.

11

Modelling research of the characteristics of gasturbine axial compressor with changeable flow passage geometry

80%

Wirkowski P.

Journal of KONES

|

2011

|

tom Vol. 18, No. 3

507-514

EN

In real exploitational conditions marine gasturbine engine works at different rotation speeds determined by the required parameters of ship's movement. Conversion from one rotation speed to another is related to realization of unsteady energetic processes, determined by the gasodynamic mutual influence of compressor configurations. The values of working medium flow thermodynamic parameters undergo significant changes in time. To work out the qualitative and quantitative estimation of these changes it is necessary to define the dynamic equations, describing working medium flow through the gas passage of engine. In the next step it is necessary to resolve the defined equations for disturbances of steady cooperation of compressor configurations. This paper concerns the application of mathematical modelling methods to analyzing gas-dynamic processes in marine gas turbines. The influence of geometry changes in axial compressor flow passage on kinematical air flow characteristics is presented. The elaborated mathematical model will make it possible to realize - in the future -simulative investigations of gas-dynamic processes taking place in a compressor fitted with controllable guide vanes. Individual parametric features of every engine in service are identified by using expensive experimental tests, which are conditioned by many constructional and operational limitations. The dynamic development of computer technology, enables using it for numerical simulation of changeable technical state processes.

12

Analiza zjawisk nieustalonych oraz zanikania śladu pozałopatkowego w przepływie za kołem wirnikowym osiowego niskoobrotowego stopnia sprężającego

70%

Witkowski A. , Chmielniak T. , Żukowski J.

Zeszyty Naukowe. Cieplne Maszyny Przepływowe - Turbomachinery / Politechnika Łódzka

|

2000

|

tom nr 117, vol. 1

279-286

PL

W pracy przedstawiono wyniki badań nieustalonego pola prędkości, za kołem wirnikowym osiowego stopnia sprężającego, z wykorzystaniem systemu pomiarowego próbkowania cyklicznego przy zastosowaniu czujników termo-anemometrycznych z trójdzielną folią. Szczególną uwagę zwrócono na analizę rozkładu wzdłuż wysokości kanału zjawisk nieustalonych losowych i periodycznych w przestrzeni międzywieńcowej koła wirnikowego i kierownicy tylnej w funkcji obciążenia aerodynamicznego stopnia. Rozkłady te umożliwiają wyodrębnienie i ocenę jakościową obszarów podatnych na występowanie strat przepływowych i oderwań strug.

EN

In the paper the three-dimensional unsteady flow field downstream of the rotor of the axial flow compressor stage has been investigated experimentally using an periodic multi-sampling measuring system with triple-split fibre probes. Special emphasis on analysis of the periodic and unresolved unsteadiness downstream of the trailing edge of the rotor blade at different point of operation has been mode. These distributions get us possible to isolate and qualitative evaluate the flow regions mainly sensitive for appear losses and flow separation.

13

Numerical loss analysis on slot-type casing treatment in a transonic compressor stage

70%

Zhu M.-M. , Qiang X.-Q. , Teng J.-F.

Journal of Theoretical and Applied Mechanics

|

2017

|

tom Vol. 55 nr 1

293--306

EN

To understand the loss mechanism of slot-type casing treatment, a numerical loss analysis has been carried out in a 1.5 axial transonic compressor stage with various slots. Spanwise and streamwise distribution curves of pitch-averaged entropy have been presented to survey the development of loss generation. Further, detailed entropy distributions at eight axial cuts, which have been taken through the blade row and slots, have been further analyzed to interpret the loss mechanism. The most dramatic loss growth occurred above 95% span, which directly resulted from slots injection flow upstream the leading edge. Loss generations with smooth casing have been primarily ascribed to low-momentum tip leakage flow/vortex and suction surface separation at the leading edge. CU0 slot, the arc-curved slots with 50% rotor tip exposure, has been capable of suppressing the suction surface separation loss. Meanwhile, accelerated tip leakage flow brought about additional loss near the casing and pressure surface. Upstream high entropy flow would be absorbed into the rear portion of slots repeatedly, which resulted in further loss.

14

Investigation of inlet distortion effects on axial compressor performance based on streamline curvature method

70%

Abbasi S. , Pirnia A. , Taghavi-Zenouz R.

Journal of Theoretical and Applied Mechanics

|

2018

|

tom Vol. 56 nr 4

1005--1015

EN

In this paper, the effects of inlet flow distortion on performance maps and details of the flow field are investigated using the Streamline Curvature Method. The results are presented for both design and off-design conditions and compared with experimental data, which shows good agreement. The effects of inlet flow distortion are investigated by inlet total pressure variation in three different cases in the way that the average total pressure remains constant and equal to the design value. The results show that a relative increase in the total pressure at tip causes an increase in the pressure ratio and efficiency as well as a better performance in the choking region. Alternatively, a relative increase in the total pressure in hub causes opposite behavior and a better performance at the surging region.

15

Off-design behaviour of a three stage axial compressor with controlled diffusion airfoils

70%

Bohne A. , Hoynacki A. , Niehuis R. , Gallus H. E.

Zeszyty Naukowe. Cieplne Maszyny Przepływowe - Turbomachinery / Politechnika Łódzka

|

1999

|

tom nr 115

37--46

EN

In order to provide detailed experimental data to improve the state-of-the-art design tools for turbomachinery, a three stage high speed axial compressor with CDA is investigated covering its operation range up to full-load conditions. The results of the steady flow measurements characterise the overall performance of the machine and the behaviour of the blading under off-design conditions. The results emphasise the remarkable dependence of secondary flow phenomena as the wake durability and the region affected by the tip clearance vortex on different load conditions. Furthermore a close correlation between the blade loading of the last stator and the overall compressor performance can be detected.

16

Modelling research of the characteristics of gasturbine axial compressor with changeable flow passage geometry

70%

Wirkowski P.

Logistyka

|

2010

|

tom nr 6

EN

One of the most important problems of exploitational use of marine gasturbine engine is knowledge about direction of changes realised unsteady processes. Individual dynamical features of each exploitated engine are determined on the way of costly experimental searches. These searches are qualified by numerous constructional and exploitational confinements. This paper concerns the application of mathematical modeling methods to analyzing gas-dynamic processes in marine gas turbines. The influence of geometry changes in axial compressor flow passage on kinematical air flow characteristics is presented. The elaborated mathematical model will make it possible to realize - in the future - simulative investigations of gas-dynamic processes taking place in a compressor fitted with controllable guide vanes.

PL

Referat dotyczy zastosowania metod modelowania matematycznego do analizy procesów gazodynamicznych w okrętowych turbinowych silnikach spalinowych. Przedstawiono wpływ zmian geometrii kanału przepływowego sprężarki osiowej na charakterystyki kinematyczne przepływającego powietrza. Opracowany model matematyczny umożliwi w przyszłości realizację badań symulujących procesy gazodynamiczne zachodzące w sprężarce wyposażonej w regulowane kierownice.

17

Development of flow and efficiency characteristics of an axial compressor with an analytical method including cooling air extraction and variable inlet guide vane angle

70%

Trawiński P.

Archives of Thermodynamics

|

2021

|

tom Vol. 42, no 4

17--46

EN

The development of a reliable mathematical model of an axial compressor requires applying flow and efficiency characteristics. This approach provides performance parameters of a machine depending on varying conditions. In this paper, a method for developing characteristics of an axial compressor is presented, based on general compressor maps available in the literature or measurement data from industrial facilities. The novelty that constitutes the core of this article is introducing an improved method describing the performance lines of an axial compressor with the modified ellipse equation. The proposed model is extended with bleed air extraction for the purposes of cooling the blades in the expander part of the gas turbine. The variable inlet guide vanes angle is also considered using the vane angle correction factor. All developed dependencies are fully analytical. The presented approach does not require knowledge of machine geometry. The set of input parameters is based on reference data. The presented approach makes it possible to determine the allowed operating area and study the machine’s performance in variable conditions. The introduced mathematical correlations provide a fully analytical study of optimum operating points concerning the chosen criterion. The final section presents a mathematical model of an axial compressor built using the developed method. A detailed study of the exemplary flow and efficiency characteristics of an axial compressor operating with a gas turbine is also provided.

18

Zależność parametrów pracy silnika turbinowego od zmiany geometrii kanału przepływowego sprężarki osiowej

60%

Wirkowski P.

Logistyka

|

2010

|

tom nr 4

CD-CD

PL

W artykule przedstawiono zagadnienie wpływu zmian ustawienia regulowanych łopatek kierownicy sprężarki osiowej na parametry pracy sprężarki oraz całego silnika turbinowego. Nieprawidłowe funkcjonowanie systemu zmiany ustawienia regulowanych łopatek sprężarki osiowej silnika turbinowego może powodować niestabilną pracę sprężarki przenoszoną na konstrukcję silnika. Jeżeli w konstrukcji sprężarki silnika turbinowego występuje układ zmiany ustawienia regulowanych łopatek kierownic, mający za zadanie optymalne kojarzenie współpracy wszystkich zespołów silnika turbinowego poprzez ciągłą korektę charakterystyki sprężarki, to występujące zakłócenia w pracy tego układu będą powodowały zmiany zakresu pracy sprężarki i silnika o charakterze podobnym, jaki powodują zmiany prędkości obrotowej wirnika czy też zanieczyszczone kanały międzyłopatkowe sprężarki. W artykule zaprezentowana została analiza teoretyczna powyższego zjawiska oraz przedstawiono wyniki badań przeprowadzonych na obiekcie rzeczywistym.

EN

The paper deals with the problem of influence of changes variable stator vanes axial compressor settings of gas turbine engine on work parameters of compressor and engine. Incorrect operation of change setting system of variable vanes could make unstable work of compressor and engine. This paper presents theoretical analysis of situation described above and results of own research done on real engine. On the base of results of experiment there were determined mathematical equations determining relationships of changes of particular engine work parameters in function of variable inlet guide stator vanes setting angle. There are presented results of the solution of mathematical equations, which describe the changes of engine work parameters values too.

19

Influence of Axial Compressor Model Simplification and Mesh Density on Surge Margin Evaluation

60%

Muchowski R. , Gubernat S. M.

Advances in Science and Technology. Research Journal

|

2021

|

tom Vol. 15, no 3

243--253

EN

The menace of surge occurrence in the compressors is taken very seriously and its avoidance became a fundamental for the design of any modern jet engines. Nowadays, a problem with appropriate evaluation of the compressor surge margin while considering different simplifications of three-dimensional CFD model is still present. For that purpose, this article presents a comparison between the measurement data and several variants of 3D CFD models characterized by a specific mesh density. To calculate all the results on which the comparisons and conclusions are based, an 8-stage axial compressor is taken into account. Flow conditions of the machine are computed for three part load speeds: The low, the mid and the high one respecting the variable guide vanes schedule fitted to the specific load. For each of speed variants a four mesh configurations were generated: coarse, medium, fine and extra-fine. All speed configurations were treated with two different turbulence models – Wilcox k-ω and Menter’s SST k-ω, giving ultimately 15 CFD models, calculated with the TRACE solver using an initialization based on a circumferentially averaged flow solution delivered by the Streamline Curvature Method. During the study an additional assessment of reference grid independence was performed and the mesh convergence has been achieved. A comparison between turbulence models and the measurement proves that SST turbulence model is not well distributed through the speeds in compare to the measurement data and the Wilcox turbulence model. Inconsistency of sensitivity in the mesh coarsening for different rotational speeds was found. Increasing the mesh roughness level has to be executed for each speed separately. Overall compressor map shows that shift of the Pressure Ratio and the Mass Flow decreases with lower rotational speed. Neglecting the system add-ons like labyrinth sealing volumes, bleed-ports and other leakages has a visible influence on deviations from the measurements. Because of intended future use in design and optimization the “Medium” grid with Wilcox k-ω turbulence model was chosen, being a good representation of the Rig characteristics with reduction of the computing time.

20

Correlation between gas turbine engine work parameters and axial compressor flow passage geometry changes

60%

Wirkowski P.

Logistyka

|

2009

|

tom nr 6

CD-CD

EN

The paper deals with the problem of influence of changes variable stator vanes axial compressor settings of gas turbine engine on work parameters of compressor and engine. Incorrect operation of change setting system of variable vanes could make unstable work of compressor and engine. This paper presents theoretical analysis of situation described above and results of own research done on real engine. On the base of results of experiment there were determined mathematical equations determining relationships of changes of particular engine work parameters in function of variable inlet guide stator vanes setting angle. There are presented results of the solution of mathematical equations, which describe the changes of engine work parameters values too.

PL

Nieprawidłowe funkcjonowanie systemu zmiany ustawienia regulowanych łopatek sprężarki osiowej silnika turbinowego może powodować niestabilną pracę sprężarki przenoszoną na konstrukcję silnika. W artykule zaprezentowana została analiza teoretyczna powyższego zjawiska oraz przedstawiono wyniki badań przeprowadzonych na rzeczywistym obiekcie. Następnie na bazie przeprowadzonych badań określone zostały równania matematyczne opisujące zależności pomiędzy wartościami rozpatrywanych parametrów pracy silnika a kątem ustawienia regulowanych łopatek. Równania te posłużyły do zasymulowania zmian wartości parametrów dla zakresu zmian kąta regulowanych łopatek nieosiągalnego podczas badań na obiekcie rzeczywistym.