The Effect of Vane Clocking on the Unsteady Flow Field in a One-and-a-Half Stage Transonic Turbine

2008 ◽  
Vol 130 (3) ◽  
Author(s):  
O. Schennach ◽  
R. Pecnik ◽  
B. Paradiso ◽  
E. Göttlich ◽  
A. Marn ◽  
...  
Keyword(s):  
Laser Doppler Velocimetry ◽  
Three Dimensional ◽  
Fast Response ◽  
Navier Stokes ◽  
Doppler Velocimetry ◽  
Pressure Transducers ◽  
Wake Interactions ◽  
Transonic Turbine ◽  
Response Pressure ◽  
Vane Clocking

The current paper presents the results of numerical and experimental clocking investigations performed in a high-pressure transonic turbine with a downstream vane row. The objective was a detailed analysis of shock and wake interactions in such a 1.5-stage machine while clocking the vanes. Therefore, a transient 3D Navier–Stokes calculation was done for two clocking positions, and the three-dimensional results are compared with laser-Doppler-velocimetry measurements at midspan. Additionally, the second vane was equipped with fast response pressure transducers to record the instantaneous surface pressure for 20 different clocking positions at midspan.

The Effect of Vane Clocking on the Unsteady Flowfield in a One and a Half Stage Transonic Turbine

2007 ◽  
Author(s):  
O. Schennach ◽  
R. Pecnik ◽  
B. Paradiso ◽  
E. Go¨ttlich ◽  
A. Marn ◽  
...  
Keyword(s):  
Laser Doppler Velocimetry ◽  
Three Dimensional ◽  
Fast Response ◽  
Navier Stokes ◽  
Doppler Velocimetry ◽  
Pressure Transducers ◽  
Wake Interactions ◽  
Transonic Turbine ◽  
Response Pressure ◽  
Vane Clocking

The current paper presents the results of numerical and experimental clocking investigations performed in a high-pressure transonic turbine with a downstream vane row. The objective was a detailed analysis of shock and wake interactions in such a 1.5 stage machine while clocking the vanes. Therefore a transient 3D-Navier Stokes calculation was done for two clocking positions and the three dimensional results are compared with Laser-Doppler-Velocimetry measurements at midspan. Additionally the second vane was equipped with fast response pressure transducers to record the instantaneous surface pressure for 20 different clocking positions at midspan.

Experimental Investigations of Clocking in a One and a Half Stage Transonic Turbine Using Laser-Doppler-Velocimetry and a Fast Response Aerodynamic Pressure Probe

2006 ◽  
Author(s):  
O. Schennach ◽  
J. Woisetschla¨ger ◽  
A. Fuchs ◽  
E. Go¨ttlich ◽  
A. Marn ◽  
...  
Keyword(s):  
Flow Field ◽  
Laser Doppler Velocimetry ◽  
Fast Response ◽  
Laser Doppler ◽  
Experimental Investigations ◽  
Pressure Probe ◽  
Doppler Velocimetry ◽  
Flow Angle ◽  
Aerodynamic Pressure ◽  
Transonic Turbine

The current paper presents experimental clocking investigations of the flow field in midspan in a high-pressure transonic turbine with a downstream vane row (1.5 stage machine). Laser-Doppler-Velocimetry measurements were carried out in order to record rotor phase resolved velocity, flow angle and turbulence distributions upstream and downstream of the second vane row at several different vane-vane positions. Additionally, a fast response aerodynamic pressure probe was used to get the total pressure distribution downstream of the second vane row for the same positions. Altogether, the measurements were performed for ten different 1st vane to 2nd vane positions (clocking positions) for measurements downstream of the 2nd vane row and two different clocking positions for measurements upstream of the 2nd vane row. The paper shows that different clocking positions have a significant influence on the flow field downstream of the 2nd vane row. Furthermore different measurement lines upstream of the 2nd vane row indicate that clocking has nearly no influence on the flow field close to the rotor exit.

Unsteady Velocity- and Turbulence Measurements With a Fast Response Pressure Probe

1990 ◽  
Author(s):  
G. Ruck ◽  
H. Stetter
Keyword(s):  
Dynamic Behaviour ◽  
Three Dimensional ◽  
Mechanical Damage ◽  
Axial Compressor ◽  
Fast Response ◽  
Pressure Probe ◽  
Pressure Transducers ◽  
Rotating Blade ◽  
Response Pressure ◽  
Probe Head

To investigate the three-dimensional unsteady flow and the turbulence intensities behind rotating blade rows of turbomachines, a procedure using a fast-response pressure probe has been developed. The integration of the cylindrical miniature pressure transducers into the probe head minimizes the risk of mechanical damage. The dynamic behaviour of the probe was analyzed. The application of the probe to the rotor exit flow of an axial compressor is described and results are presented.

scholarly journals Influence of Vane-Blade Spacing on Transonic Turbine Stage Aerodynamics: Part 1 — Time-Averaged Data and Analysis

1998 ◽  
Author(s):  
Brian L. Venable ◽  
Robert A. Delaney ◽  
Judy A. Busby ◽  
Roger L. Davis ◽  
Daniel J. Dorney ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Pressure Sensors ◽  
Navier Stokes ◽  
Turbine Stage ◽  
Airfoil Surface ◽  
Blade Row ◽  
Turbine Vane ◽  
Transonic Turbine ◽  
Response Pressure ◽  
And Performance

A comprehensive study has been performed to determine the influence of vane-blade spacing on transonic turbine stage aerodynamics. In Part I of this paper, an investigation of the effect of turbine vane-blade interaction on the time-mean airfoil surface pressures and overall stage performance parameters is presented. Experimental data for an instrumented turbine stage are compared to two- and three-dimensional results from four different time-accurate Navier-Stokes solvers. Unsteady pressure data were taken for three vane-blade row spacings in a short-duration shock tunnel using surface-mounted, high-response pressure sensors located along the midspan of the airfoils. Results indicate that while the magnitude of the surface pressure unsteadiness on the vane and blade changes significantly with spacing, the time-mean pressures and performance numbers are not greatly affected.

Investigation of Unsteady Flow Through a Transonic Turbine Stage: Data/Prediction Comparison for Time-Averaged and Phase-Resolved Pressure Data

1992 ◽  
Vol 114 (1) ◽  
pp. 91-99 ◽  
Author(s):  
M. G. Dunn ◽  
W. A. Bennett ◽  
R. A. Delaney ◽  
K. V. Rao
Keyword(s):  
Pressure Ratio ◽  
Design Flow ◽  
Navier Stokes ◽  
Design Stage ◽  
Pressure Data ◽  
Pressure Transducers ◽  
Data Prediction ◽  
Flow Through ◽  
Transonic Turbine ◽  
Response Pressure

This paper presents time-averaged and phase-resolved measurements of the surface pressure data for the vane and blade of a transonic single-stage research turbine. The data are compared and contrasted with predictions from an unsteady Euler/Navier–Stokes code. The data were taken in a shock-tunnel facility in which the flow was generated with a short-duration source of heated and pressurized air. Surf ace-mounted high-response pressure transducers were used to obtain the pressure measurements. The turbine was operating at the design flow function, the design stage pressure ratio, and 100 percent corrected speed. A matrix of data was obtained at two vane exit conditions and two vane/rotor axial spacings.

Influence of Vane-Blade Spacing on Transonic Turbine Stage Aerodynamics: Part I—Time-Averaged Data and Analysis

1999 ◽  
Vol 121 (4) ◽  
pp. 663-672 ◽  
Author(s):  
B. L. Venable ◽  
R. A. Delaney ◽  
J. A. Busby ◽  
R. L. Davis ◽  
D. J. Dorney ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Pressure Sensors ◽  
Navier Stokes ◽  
Turbine Stage ◽  
Airfoil Surface ◽  
Blade Row ◽  
Turbine Vane ◽  
Transonic Turbine ◽  
Response Pressure ◽  
And Performance

A comprehensive study has been performed to determine the influence of vane-blade spacing on transonic turbine stage aerodynamics. In Part I of this paper, an investigation of the effect of turbine vane–blade interaction on the time-mean airfoil surface pressures and overall stage performance parameters is presented. Experimental data for an instrumented turbine stage are compared to two- and three-dimensional results from four different time-accurate Navier–Stokes solvers. Unsteady pressure data were taken for three vane-blade row spacings in a short-duration shock tunnel using surface-mounted, high-response pressure sensors located along the midspan of the airfoils. Results indicate that while the magnitude of the surface pressure unsteadiness on the vane and blade changes significantly with spacing, the time-mean pressures and performance numbers are not greatly affected.

An axisymmetric ‘fluidic’ nozzle to generate jet precession

1998 ◽  
Vol 370 ◽  
pp. 347-380 ◽  
Author(s):  
G. J. NATHAN ◽  
S. J. HILL ◽  
R. E. LUXTON
Keyword(s):  
Flow Visualization ◽  
Large Scale ◽  
Three Dimensional ◽  
Fast Response ◽  
Surface Flow ◽  
Sudden Expansion ◽  
Pressure Transducers ◽  
Acoustic Coupling ◽  
Response Pressure ◽  
Surface Flow Visualization

A continuously unstable precessing flow within a short cylindrical chamber following a large sudden expansion is described. The investigation relates to a nozzle designed to produce a jet which achieves large-scale mixing in the downstream field. The inlet flow in the plane of the sudden expansion is well defined and free from asymmetry. Qualitative flow visualization in water and semi-quantitative surface flow visualization in air are reported which identify this precession within the chamber. Quantitative simultaneous measurements from fast-response pressure transducers at four tapping points on the internal walls of the nozzle chamber confirm the presence of the precessing field. The investigation focuses on the flow within the nozzle chamber rather than that in the emerging jet, although the emerging flow is also visualized.Two flow modes are identified: a ‘precessing jet’ mode which is instantaneously highly asymmetric, and a quasi-symmetric ‘axial jet’ mode. The precessing jet mode, on which the investigation concentrates, predominates in the geometric configuration investigated here. A topologically consistent flow field, derived from the visualization and from the fluctuating pressure data, which describes a three-dimensional and time-dependent precessing motion of the jet within the chamber is proposed. The surface flow visualization quantifies the axial distances to lines of positive and negative bifurcation allowing comparison with related flows involving large-scale precession or flapping reported by others. The Strouhal numbers (dimensionless frequencies) of these flows are shown to be two orders of magnitude lower than that measured in the shear layer of the jet entering the chamber. The phenomenon is demonstrated to be unrelated to acoustic coupling.

Experimental Investigations of Clocking in a One-and-a-Half-Stage Transonic Turbine Using Laser Doppler Velocimetry and a Fast Response Aerodynamic Pressure Probe

2006 ◽  
Vol 129 (2) ◽  
pp. 372-381 ◽  
Author(s):  
O. Schennach ◽  
J. Woisetschläger ◽  
A. Fuchs ◽  
E. Göttlich ◽  
A. Marn ◽  
...  
Keyword(s):  
Flow Field ◽  
Laser Doppler Velocimetry ◽  
Fast Response ◽  
Laser Doppler ◽  
Experimental Investigations ◽  
Pressure Probe ◽  
Doppler Velocimetry ◽  
Flow Angle ◽  
Aerodynamic Pressure ◽  
Transonic Turbine

The current paper presents experimental clocking investigations of the flow field in midspan in a high-pressure transonic turbine with a downstream vane row (1.5 stage machine). Laser-Doppler-velocimetry measurements were carried out in order to record rotor phase resolved velocity, flow angle, and turbulence distributions upstream and downstream of the second vane row at several different vane-vane positions. Additionally, a fast-response aerodynamic pressure probe was used to get the total pressure distribution downstream of the second vane row for the same positions. Altogether, the measurements were performed for ten different first vane to second vane positions (clocking positions) for measurements downstream of the second vane row and two different clocking positions for measurements upstream of the second vane row. The paper shows that different clocking positions have a significant influence on the flow field downstream of the second vane row. Furthermore, different measurement lines upstream of the second vane row indicate that clocking has nearly no influence on the flow field close to the rotor exit.

The Effect of the Operating Point on the Pressure Fluctuations at the Blade Passage Frequency in the Volute of a Centrifugal Pump

2002 ◽  
Vol 124 (3) ◽  
pp. 784-790 ◽  
Author(s):  
Jorge L. Parrondo-Gayo ◽  
Jose´ Gonza´lez-Pe´rez ◽  
Joaquı´n Ferna´ndez-Francos
Keyword(s):  
Centrifugal Pump ◽  
Pressure Fluctuations ◽  
Fast Response ◽  
Strong Increase ◽  
Flow Rates ◽  
Blade Passage ◽  
Pressure Transducers ◽  
Leading Role ◽  
Dynamic Forces ◽  
Response Pressure

An experimental investigation is presented which analyzes the unsteady pressure distribution existing in the volute of a conventional centrifugal pump with a nondimensional specific speed of 0.48, for flow-rates from 0% to 160% of the best-efficiency point. For that purpose, pressure signals were obtained at 36 different locations along the volute casing by means of fast-response pressure transducers. Particular attention was paid to the pressure fluctuations at the blade passage frequency, regarding both amplitude and phase delay relative to the motion of the blades. Also, the experimental data obtained was used to adjust the parameters of a simple acoustic model for the volute of the pump. The results clearly show the leading role played by the tongue in the impeller-volute interaction and the strong increase in the magnitude of dynamic forces and dipole-like sound generation in off-design conditions.

Analysis of pulsating flow measurement of engine exhaust by a Pitot tube flowmeter

2005 ◽  
Vol 6 (1) ◽  
pp. 85-93 ◽  
Author(s):  
H Nakamura ◽  
I Asano ◽  
M Adachi ◽  
J Senda
Keyword(s):  
Fast Response ◽  
Differential Pressure ◽  
Pulsating Flow ◽  
Pitot Tube ◽  
Engine Exhaust ◽  
Idle Speed ◽  
Pressure Transducers ◽  
Vehicle Engine ◽  
Before And After ◽  
Response Pressure

The Pitot tube flowmetering technique has been used to measure pulsating flow from a vehicle engine exhaust. In general, flowmetering techniques that utilize differential pressure measurements based on Bernoulli's theory are likely to show erroneous readings when measuring an average flowrate of pulsating flow. The primary reason for this is the non-linear relationship between the differential pressure and the flowrate; i.e. the flowrate is proportional to the square root of the differential pressure. Therefore, an average of the differential pressure does not give an average of pulsating flow. In this study, fast response pressure transducers have been used to measure the pulsating pressure. Then the pulsating differential pressure is converted to the flowrate while keeping the pulsation unaveraged. An average flowrate is then calculated in the flowrate domain in order to maintain linearity before and after averaging. The peak amplitude of a pulsation measured here was about 1800 L/min at an average flowrate of 70 L/min when the engine ran at idle speed. This measurement has been confirmed by measuring the pulsation with a gas analyser. The results show a large amount of back and forth gas movement in the exhaust tube. This magnitude of pulsation can cause as much as five times higher erroneous results with the pressure domain averaging when compared to a flowrate domain averaging.

Sign in / Sign up

Export Citation Format

Share Document