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1
Content available Numerical investigation of compressor rotor blade clocking effects on aerodynamic loading of the stator vane
Yan P. G., Qiang X. Q., Du Z. H., Han W. J.
Journal of Theoretical and Applied Mechanics
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2012
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Vol. 50 nr 2
423-440
EN
The unsteady flow fields of a three-stage axial compressor are simulated. The 3D N-S equations are solved by using the frequency domain transformed method based on the harmonic function. The main efforts are focused on the effects of the second stage rotor blade clocking configuration on aerodynamic loading of the stator vanes. The unsteady aerodynamic loadings of each blade row are analyzed in time and frequency domains. The results point out that the aerodynamic loading of the middle stage stator vane is significantly affected as the rotor blades changing with different clocking configuration. At CLK0 configuration, the middle stage stator vane is affected by the aerodynamic force whose direction is sometimes reverse with the regular force. At CLK2 configuration, the aerodynamic force of the stator vane is always positive and the fluctuation amplitude is smaller than those of other configurations. Meanwhile, the response of stator vane S2 to one blade passing frequency (BPF) is minimum comparing to others.
PL
Praca zawiera wyniki symulacji numerycznej nieustalonego pola przepływu w trójstopniowej sprężarce osiowej. Trójwymiarowe równania Naviera-Stokesa rozwiązano metodą transformacji w dziedzinie częstości opartej na funkcji harmonicznej. Główny wysiłek włożono w badania wpływu konfiguracji łopat kierownicy i wirnika drugiego stopnia sprężarki na obciążenie aerodynamiczne kierownicy. Obciążenie to o charakterze nieustalonym przeanalizowano dla każdego rzędu łopatek w dziedzinie czasu i częstości. Wyniki wykazały, że obciążenie aerodynamiczne kierownicy środkowego stopnia sprężarki znacząco zależy od wzajemnego ustawienia łopat wirnika i kierownicy. Dla konfiguracji oznaczonej CLK0 kierownica podlega obciążeniu siłą, której zwrot bywa przeciwny do kierunku typowego w przypadkach regularnych. Natomiast konfiguracją CLK2 generuje zawsze dodatnią wartość siły aerodynamicznej, której fluktuacje amplitudy są jednocześnie mniejsze niż w innych konfiguracjach. Ponadto stwierdzono, że wrażliwość aerodynamiczna łopaty kierownicy S2 na częstotliwość łopatkową (BPF) jest minimalna w stosunku do innych konfiguracji.
2
Content available remote Vane bowing and clocking technique influence on two-stage turbine performance
Krysiński J., Smolny A., Błaszczak J. R.
Zeszyty Naukowe. Cieplne Maszyny Przepływowe - Turbomachinery / Politechnika Łódzka
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2008
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nr 133
175--186
EN
This paper describes the experimental investigations of the clocking effects on the turbine performance characteristics. The turbine was equipped with rake temperature and pressure probes and fast response miniature pressure sensors and surface-mounted hot film sensors. To understand better an interaction mechanism and show how some flow effects can be successfully employed in estimation and correlation of stage losses, quasi-three-dimensional simulations of the airfoil clocking have been performed. Time-averaged and unsteady data including performance of particular blade/vane rows are presented and used to minimize the stage loss production due to upstream flow conditions. The results show a turbine total efficiency variation from 0.1% to 0.5%. The experiments have shown that the clocking effect seems to be mainly related to the low momentum flow region, which should be introduced into a leading edge region of the downstream vane/blade row, where the fluid momentum will be already low. Primary loss production in the blade row will be a function of the geometry and inlet time mean flow conditions and the distribution along the circumferential direction.
3
Content available remote Two-stage turbine performance improvement and noise reduction through stator-to-stator and rotor-to-rotor clocking
Błaszczak J. R.
Zeszyty Naukowe. Cieplne Maszyny Przepływowe - Turbomachinery / Politechnika Łódzka
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2008
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nr 133
59--68
EN
In order to obtain better performances and reduction of noise emitted by modern turbomachines, the understanding of an influence of different geometry is essential. The experimental work presented in the paper is a continuation of earlier studies on effects of different geometry configurations. Till now only the stator-to-stator indexing (clocking) effect was considered. Nowadays main attention is directed to rotor-to-rotor clocking. A turbine with two identical stages was investigated. New geometry has been used. Special attention was drawn to noise emitted by the turbine due to the vane-to-vane and blade-to-blade clocking influences. It has been correlated to the overall performance (torque) of the turbine of new design and additional comparison has been done to the vane-to-vane indexing benefit. All results have been compared to the classical design positions of stators and rotors. The measurements presented in this paper have been performed at the nominal speed and at one off-design rotational speed of the machine. The rotor-to-rotor indexing turned out to be more advantageous than the stator-to-stator clocking and only a slight change in the rotor position is needed to yield higher efficiency. Similar influence has been observed for the emitted noise level. All measurements have been performed inside especially designed anechoic room.
4
Content available remote Stator-to-Stator and Rotor-to-Rotor Clocking Measurements in a Two-Stage Low-Pressure Model Turbine
Świderek M., Błaszczak J.
Zeszyty Naukowe. Cieplne Maszyny Przepływowe - Turbomachinery / Politechnika Łódzka
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2006
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Nr 129, vol. 1
71-78
EN
The objective of the presented test program was to investigate the influence of the stator-to-stator and the rotor-to-rotor clocking on the performance in a two-stage low-pressure turbine. Keeping inlet conditions under constant control two turbine stages were experimentally investigated. Experimental data were obtained for nominal as well as for off-design speeds. The experimental investigations have been carried out on a two-stage turbine research facility at the Institute of the Turbomachinery of the Technical University of Lodz, Poland.
5
Content available remote Vibro-Acoustic Variations Due to the Clocking Effect in a Two-Stage Turbine
Błaszczak J. R.
Zeszyty Naukowe. Cieplne Maszyny Przepływowe - Turbomachinery / Politechnika Łódzka
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2005
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nr 128, vol. 1
61-68
EN
The objective of the presented test program was to investigate vaneindexing effect influence on the performance, noise and vibration of a two-stage turbine. Some measurement results for different circumferential positions of the vanes are described to determine how noise and vibration could be affected by airfoil indexing. Two cases are presented: for nominal rotational speed and for off-design turbine conditions. The investigations have been carried out at the Institute of Turbomachinery (Technical University of Lodz, Poland).
6
Content available remote Stator Wake Dissipation in the Turbine Rotor Passage
Świrydczuk J.
Zeszyty Naukowe. Cieplne Maszyny Przepływowe - Turbomachinery / Politechnika Łódzka
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2005
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nr 128, vol. 2
531-538
EN
The paper discusses the effect of grid resolution on proper modelling of dissipation of the stator wake on its way through the rotor passage. Comparison is made between solutions, our own and available in the literature, of the stator/rotor interaction calculated using different RANS codes. The reference material consists of experimental data and those obtained with the aid of the vortex dynamics theory (VDT). The final conclusion of the study suggests grid resolution ranges that may produce wake dissipation patterns acceptable from the point of view of accuracy and time consumption.
7
Content available remote Static Pressure Variations on a Turbine Vane Due to the Clocking Effect
Błaszczak J. R., Borzęcki T.
Zeszyty Naukowe. Cieplne Maszyny Przepływowe - Turbomachinery / Politechnika Łódzka
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2005
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nr 128, vol. 1
69-78
EN
The objective of the presented test program was to investigate vane clocking effect influence on the performance of a two-stage model turbine at the Institute of Turbomachinery of the Technical University of Lodz, Poland. Keeping the inlet conditions strictly constant during the tests, two turbine stages were investigated. Herein, some flow measurement results and the machine performance for two indexing positions are described. Comparisons were made with numerical simulation for nominal rotational speed and for off-design turbine conditions.
8
Content available remote Badania wpływu wzajemnego położenia kierownic na sprawność dwustopniowej turbiny modelowej
Smolny A.
Zeszyty Naukowe. Cieplne Maszyny Przepływowe - Turbomachinery / Politechnika Łódzka
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2000
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nr 116
9--16
PL
Wykonano badania wpływu wzajemnego położenia kierownic dwustopniowej turbiny na jej charakterystyki zewnętrzne (przepływ, moment, sprawność) dla 5 punktów pracy turbiny. Badania mają duże znaczenie dla optymalnego ustawienia wzajemnego kierownic w wielostopniowych maszynach przepływowych.
EN
This paper concern experimental investigations conducted for detailed studies of the clocking effect in a two-stage low pressure turbine. Paper describes details of the test facility and aerodynamic operating parameters. Measured turbine efficiency was used to quantify the effect of stator clocking positions on turbine performance.
9
Content available remote Stator clocking effect investigations in a two-stage turbine
Krysiński J. E., Smolny A., Blaszczak J. R., Gallus H. E.
Zeszyty Naukowe. Cieplne Maszyny Przepływowe - Turbomachinery / Politechnika Łódzka
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1999
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nr 115
241--250
EN
Experimental investigations of external characteristics and the detailed flow structures in a two-stage low-pressure turbine were conducted. The objective of this study was to gain more insight into unsteady flow phenomena affecting flow behaviour due to the stator wake clocking effects in multi-stage machines. A clocking mechanism allows the first stator to be moved relative to the second stage stator. Analysis of the experimental results includes turbine performance as well as steady and unsteady flow measurements throughout the flow field for different circumferential positions of both stators. A global review of the clocking effect is presented.
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