Development of a Lifetime Pressure Sensitive Paint Procedure for High-Pressure Vane Testing

2021 ◽  
Author(s):  
Papa Aye N. Aye-Addo ◽  
Guillermo Paniagua ◽  
David G. Cuadrado ◽  
Lakshya Bhatnagar ◽  
Antonio Castillo Sauca ◽  
...  
Keyword(s):  
High Pressure ◽  
Test Section ◽  
Static Pressure ◽  
Pressure Field ◽  
Optical Measurements ◽  
Wall Region ◽  
Pressure Amplitude ◽  
Pressure Sensitive Paint ◽  
Suction Surface ◽  
Pressure Sensitive

Abstract Optical measurements based on fast response Pressure Sensitive Paint (PSP) provide enhanced spatial resolution of the pressure field. This paper presents laser lifetime PSP at 20 kHz, with precise calibrations, and results from a demonstration in an annular vane cascade. The laser lifetime PSP methodology is first evaluated in a linear wind tunnel with a converging-diverging nozzle followed by a wavy surface. This test section is fully optically accessible with maximum modularity. A data reduction procedure is proposed for the PSP calibration, and optimal pixel binning is selected to reduce the uncertainty. In the annular test section, laser lifetime PSP was used to measure the time-averaged static pressure field on a section of the suction surface of a high-pressure turbine vane. Tests were performed at engine representative conditions in the Purdue Big Rig for Annular Stationary Turbine Analysis module at the Purdue Experimental Turbine Aerothermal Lab. The 2-D pressure results showed a gradual increase of pressure in the spanwise and flow directions, corroborated with local static pressure taps and computational results. The variation in PSP thickness was measured as a contribution to the uncertainty. The discrete Fourier transform of the unsteady pressure signal showed increased frequency content in wind-on conditions compared to wind-off conditions at the mid-span and 30% span. Compared to the mid-span region, the hub end wall region had an increase in frequencies and pressure amplitude. This result was anticipated given the expected presence of secondary flow structures in the near hub region.

scholarly journals DEVELOPMENT OF A LIFETIME PRESSURE SENSITIVE PAINT PROCEDURE FOR HIGH-PRESSURE VANE TESTING

2021 ◽  
pp. 1-21
Author(s):  
Nyansafo Aye-Addo ◽  
Guillermo Paniagua ◽  
David Gonzalez Cuadrado ◽  
Lakshya Bhatnagar ◽  
Antonio Castillo Sauca ◽  
...  
Keyword(s):  
High Pressure ◽  
Test Section ◽  
Static Pressure ◽  
Pressure Field ◽  
Optical Measurements ◽  
Wall Region ◽  
Pressure Amplitude ◽  
Pressure Sensitive Paint ◽  
Suction Surface ◽  
Pressure Sensitive

Abstract Optical measurements based on fast response Pressure Sensitive Paint (PSP) provide enhanced spatial resolution of the pressure field. This paper presents lifetime PSP at 20 kHz, with precise calibrations, and results from a demonstration in an annular vane cascade. The laser lifetime PSP methodology is first evaluated in a linear wind tunnel with a converging-diverging nozzle followed by a wavy surface. This test section is fully optically accessible with maximum modularity. A data reduction procedure is proposed for the PSP calibration, and optimal pixel binning is selected to reduce the uncertainty. In the annular test section, laser lifetime PSP was used to measure the time-averaged static pressure field on a section of the suction surface of a high-pressure turbine vane. Tests were performed at engine representative conditions in the Purdue Big Rig for Annular Stationary Turbine Analysis module at the Purdue Experimental Turbine Aerothermal Lab. The 2-D pressure results showed a gradual increase of pressure across the spanwise and flow directions, corroborated with local static pressure taps and computational results. The variation in PSP thickness was measured as a contribution to the uncertainty. The discrete Fourier transform of the unsteady pressure signal showed increased frequency content in wind-on compared to wind-off conditions at the mid-span and 30% span. Compared to the mid-span, the hub end wall region had an increase in frequencies and pressure amplitude. This result was anticipated given the expected presence of secondary flow structures at the near hub region.

ON HIGH-RESOLUTION PRESSURE AMPLITUDE AND PHASE MEASUREMENTS COMPARING FAST-RESPONSE PRESSURE TRANSDUCERS AND UNSTEADY PRESSURE-SENSITIVE PAINT

2021 ◽  
pp. 1-13
Author(s):  
Martin Bitter ◽  
Stephan Stotz ◽  
Reinhard Niehuis
Keyword(s):  
Second Harmonic ◽  
Measurement Techniques ◽  
Pressure Amplitude ◽  
Pressure Sensitive Paint ◽  
Simultaneous Application ◽  
Pressure Transducers ◽  
Unsteady Pressure ◽  
Flow Sensing ◽  
Pressure Sensitive ◽  
Perturbation Frequency

Abstract This paper presents the simultaneous application of fastresponse pressure transducers and unsteady pressure-sensitive paint (unsteady PSP) for the precise determination of pressure amplitudes and phases up to 3,000 Hz. These experiments have been carried out on a low-pressure turbine blade cascade under engine-relevant conditions (Re, Ma, Tu) in the High-Speed Cascade Wind Tunnel. Periodic blade/vane interactions were simulated at the inlet to the cascade using a wake generator operating at a constant perturbation frequency of 500 Hz. The main goal of this paper is the detailed comparison of amplitude and phase distributions between both flow sensing techniques at least up to the second harmonic of the wake generator's fundamental perturbation frequency (i.e. 1,000 Hz). Therefore, a careful assessment of the key drivers for relative deviations between measurement results as well as a detailed discussion of the data processing is presented for both measurement techniques. This discussion outlines the mandatory steps which were essential to achieve the quality as presented down to pressure amplitudes of several pascal even under challenging experimental conditions. Apart from the remarkable consistency of the results, this paper reveals the potential of (unsteady) PSP as a future key flow sensing technique in turbomachinery research, especially for cascade testing. The results demonstrate that PSP was able to successfully sense pressure dynamics with very low fluctuation amplitudes down to 8 Pa.

Modal Analysis of the Surface Pressure Field Around a Hemispherical Turret using Pressure Sensitive Paint

2018 ◽  
Author(s):  
Nicholas G. De Lucca ◽  
Stanislav Gordeyev ◽  
Jacob J. Morrida ◽  
Eric J. Jumper ◽  
Donald J. Wittich
Keyword(s):  
Modal Analysis ◽  
Surface Pressure ◽  
Pressure Field ◽  
Pressure Sensitive Paint ◽  
Pressure Sensitive

The Application of Pressure- and Temperature-Sensitive Paints to an Advanced Compressor

2000 ◽  
Vol 123 (4) ◽  
pp. 823-829 ◽  
Author(s):  
Kelly R. Navarra ◽  
Douglas C. Rabe ◽  
Sergey D. Fonov ◽  
Larry P. Goss ◽  
Chunill Hah
Keyword(s):  
Wind Tunnel ◽  
Molecular Spectroscopy ◽  
State Of The Art ◽  
Temperature Sensitive ◽  
Pressure Sensitive Paint ◽  
Suction Surface ◽  
Transonic Compressor ◽  
Pressure Sensitive ◽  
Oxygen Sensitive ◽  
Design Speed

An innovative pressure-measurement technique that employs the tools of molecular spectroscopy has been widely investigated by the aerospace community. Measurements are made via oxygen-sensitive molecules attached to the surface of interest as a coating, or paint. The pressure-sensitive-paint (PSP) technique is now commonly used in stationary wind-tunnel tests; this paper presents the use of this technique in advanced turbomachinery applications. New pressure- and temperature-sensitive paints (P/TSPs) have been developed for application to a state-of-the-art transonic compressor where pressures up to 1.4 atm and surface temperatures to 90°C are expected for the suction surface of the first-stage rotor. PSP and TSP data images have been acquired from the suction surface of the first-stage rotor at 85 percent of the corrected design speed for the compressor near-stall condition. A comparison of experimental results with CFD calculations is discussed.

Unsteady Wake and Coolant Density Effects on Turbine Blade Film Cooling Using Pressure Sensitive Paint Technique

2012 ◽  
Vol 134 (8) ◽  
Author(s):  
Akhilesh P. Rallabandi ◽  
Shiou-Jiuan Li ◽  
Je-Chin Han
Keyword(s):  
Film Cooling ◽  
Density Ratio ◽  
Suction Side ◽  
Pressure Sensitive Paint ◽  
Suction Surface ◽  
Cooling Effectiveness ◽  
Film Cooling Effectiveness ◽  
Pressure Sensitive ◽  
Unsteady Wake ◽  
Film Cooling Holes

The effect of an unsteady stator wake (simulated by wake rods mounted on a spoke-wheel wake generator) on the modeled rotor blade is studied using the pressure sensitive paint (PSP) mass-transfer analogy method. Emphasis of the current study is on the midspan region of the blade. The flow is in the low Mach number (incompressible) regime. The suction (convex) side has simple angled cylindrical film-cooling holes; the pressure (concave) side has compound angled cylindrical film-cooling holes. The blade also has radial shower-head leading edge film-cooling holes. Strouhal numbers studied range from 0 to 0.36; the exit Reynolds number based on the axial chord is 530,000. Blowing ratios range from 0.5 to 2.0 on the suction side and 0.5 to 4.0 on the pressure side. Density ratios studied range from 1.0 to 2.5, to simulate actual engine conditions. The convex suction surface experiences film-cooling jet lift-off at higher blowing ratios, resulting in low effectiveness values. The film coolant is found to reattach downstream on the concave pressure surface, increasing effectiveness at higher blowing ratios. Results show deterioration in film-cooling effectiveness due to increased local turbulence caused by the unsteady wake, especially on the suction side. Results also show a monotonic increase in film-cooling effectiveness on increasing the coolant to mainstream density ratio.

Heat Transfer for the Blade of a Cooled Stage and One-Half High-Pressure Turbine—Part II: Independent Influences of Vane Trailing Edge and Purge Cooling

2011 ◽  
Vol 134 (3) ◽  
Author(s):  
R. M. Mathison ◽  
C. W. Haldeman ◽  
M. G. Dunn
Keyword(s):  
Heat Transfer ◽  
High Pressure ◽  
Flow Rate ◽  
Pressure Field ◽  
Its Region ◽  
Coolant Flow ◽  
Coolant Flow Rate ◽  
High Pressure Turbine ◽  
Suction Surface ◽  
Trailing Edge

The independent influences of vane trailing edge and purge cooling are studied in detail for a one-and-one-half stage transonic high-pressure turbine operating at design-corrected conditions. This paper builds on the conclusions of Part I, which investigated the combined influence of all cooling circuits. Heat-flux measurements for the airfoil, platform, tip, and root of the turbine blade, as well as the shroud and the vane side of the purge cavity, are used to track the influence of cooling flow. By independently varying the coolant flow rate through the vane trailing edge or purge circuit, the region of influence of each circuit can be isolated. Vane trailing edge cooling is found to create the largest reductions in blade heat transfer. However, much of the coolant accumulates on the blade suction surface and little influence is observed for the pressure surface. In contrast, the purge cooling is able to cause small reductions in heat transfer on both the suction and pressure surfaces of the airfoil. Its region of influence is limited to near the hub, but given that the purge coolant mass flow rate is 1/8 that of the vane trailing edge, it is impressive that any impact is observed at all. The cooling contributions of these two circuits account for nearly all of the cooling reductions observed for all three circuits in Part I, indicating that the vane inner cooling circuit that feeds most of the vane film-cooling holes has little impact on the downstream blade heat transfer. Time-accurate pressure measurements provide further insight into the complex interactions in the purge region that govern purge coolant injection. While the pressures supplying the purge coolant and the overall coolant flow rate remain fairly constant, the interactions of the vane pressure field and the rotor pressure field create moving regions of high pressure and low pressure at the exit of the cavity. This results in pulsing regions of injection and ingestion.

On High-Resolution Pressure Amplitude and Phase Measurements Comparing Fast-Response Pressure Transducers and Unsteady Pressure-Sensitive Paint

2020 ◽  
Author(s):  
Martin Bitter ◽  
Stephan Stotz ◽  
Reinhard Niehuis
Keyword(s):  
Fast Response ◽  
Pressure Amplitude ◽  
Pressure Sensitive Paint ◽  
Simultaneous Application ◽  
Pressure Transducers ◽  
Unsteady Pressure ◽  
Flow Sensing ◽  
Pressure Sensitive ◽  
Perturbation Frequency ◽  
Response Pressure

Abstract This paper presents the simultaneous application of fast-response pressure transducers and unsteady pressure-sensitive paint (unsteady PSP) for the precise determination of pressure amplitudes and phases up to 3,000 Hz. These experiments have been carried out on a low-pressure turbine blade cascade under engine-relevant conditions (Re, Ma, Tu) in the High-Speed Cascade Wind Tunnel. Periodic blade/vane interactions were simulated at the inlet to the cascade using a wake generator operating at a constant perturbation frequency of 500 Hz. The main goal of this paper is the detailed comparison of amplitude and phase distributions between both flow sensing techniques at least up to the second harmonic of the wake generator’s fundamental perturbation frequency (i.e. 1,000 Hz). Therefore, a careful assessment of the key drivers for relative deviations between measurement results as well as a detailed discussion of the data processing is presented for both measurement techniques. This discussion outlines the mandatory steps which were essential to achieve the quality as presented down to pressure amplitudes of several pascal even under challenging experimental conditions. Apart from the remarkable consistency of the results, this paper reveals the potential of (unsteady) PSP as a future key flow sensing technique in turbomachinery research, especially for cascade testing. The results demonstrate that PSP was able to successfully sense pressure dynamics with very low fluctuation amplitudes down to 8 Pa.

scholarly journals Pressure Measurement on Suction Surface of a Single Vane Using Pressure-sensitive Paint

2009 ◽  
Vol 22 (2) ◽  
pp. 138-144 ◽  
Author(s):  
Qiang Zhou ◽  
Bo Liu ◽  
Limin Gao ◽  
Liusheng Chen ◽  
Miao Shi
Keyword(s):  
Pressure Measurement ◽  
Pressure Sensitive Paint ◽  
Suction Surface ◽  
Pressure Sensitive
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