Development and Application of a Fast-Response Total Temperature Probe for Turbomachinery

2017 ◽  
Vol 139 (5) ◽  
Author(s):  
Martin C. Arenz ◽  
Björn Weigel ◽  
Jan Habermann ◽  
Stephan Staudacher ◽  
Martin G. Rose ◽  
...  
Keyword(s):  
Hot Spot ◽  
Fast Response ◽  
High Temporal Resolution ◽  
Test Bed ◽  
Low Pressure Turbine ◽  
Temperature Probe ◽  
Measuring Surface ◽  
Measurement Principle ◽  
Total Temperature ◽  
Insight Into

The measurement of unsteady total temperature is of great interest for the examination of loss mechanisms in turbomachinery with respect to the improvement of the efficiency. Since conventional thermocouples are limited in frequency response, several fast-response total temperature probes have been developed over the past years. To improve the spatial resolution compared to these existing probes and maintaining a high temporal resolution, a new fast-response total temperature probe has been developed at the Institute of Aircraft Propulsion Systems (ILA), Stuttgart, Germany in cooperation with Berns Engineers, Gilching, Germany. The design of the probe allows a sensitive measuring surface below 1 mm2. A detailed insight into the design of the probe, the measurement principle, the calibration process, and an estimation of the measurement uncertainty is given in the present paper. Furthermore, to prove the functionality of the probe, first experimental results of a simple test bed and of area traverses downstream of the first rotor of a two-stage low pressure turbine are presented. It is shown, that the new probe is capable of detecting rotor characteristic effects as well as rotor-stator-interactions. In addition, a hot-spot is investigated downstream of the first rotor of the turbine, and the findings are compared to the effects known from the literature.

Development and Application of a Fast-Response Total Temperature Probe for Turbomachinery

2016 ◽  
Author(s):  
Martin C. Arenz ◽  
Björn Weigel ◽  
Jan Habermann ◽  
Stephan Staudacher ◽  
Martin G. Rose ◽  
...  
Keyword(s):  
Hot Spot ◽  
Fast Response ◽  
High Temporal Resolution ◽  
Test Bed ◽  
Low Pressure Turbine ◽  
Temperature Probe ◽  
Measuring Surface ◽  
Measurement Principle ◽  
Total Temperature ◽  
Insight Into

The measurement of unsteady total temperature is of great interest for the examination of loss mechanisms in turbomachinery with respect to the improvement of the efficiency. Since conventional thermocouples are limited in frequency response, several fast-response total temperature probes have been developed over the past years. To improve the spatial resolution compared to these existing probes and maintaining a high temporal resolution, a new fast-response total temperature probe has been developed at the Institute of Aircraft Propulsion Systems (ILA) in cooperation with Berns Engineers. The design of the probe allows a sensitive measuring surface below one square millimeter. A detailed insight into the design of the probe, the measurement principle, the calibration process, and an estimation of the measurement uncertainty is given in the present paper. Furthermore, to prove the functionality of the probe, first experimental results of a simple test bed and of area traverses downstream of the first rotor of a two-stage low pressure turbine are presented. It is shown, that the new probe is capable of detecting rotor characteristic effects as well as rotor-stator-interactions. In addition, a hot-spot is investigated downstream of the first rotor of the turbine and the findings are compared to effects known from literature.

Unsteady Total Temperature Measurements Downstream of a High-Pressure Turbine

1998 ◽  
Vol 120 (4) ◽  
pp. 760-767 ◽  
Author(s):  
D. R. Buttsworth ◽  
T. V. Jones ◽  
K. S. Chana
Keyword(s):  
Heat Transfer ◽  
High Pressure ◽  
Wind Tunnel ◽  
Convective Heat Transfer Coefficient ◽  
Fast Response ◽  
Temperature Measurements ◽  
High Pressure Turbine ◽  
Response Device ◽  
Temperature Probe ◽  
Total Temperature

An experimental technique for the measurement of flow total temperature in a turbine facility is demonstrated. Two thin film heat transfer gases located at the stagnation point of fused quartz substrates are operated at different temperatures in order to determine the flow total temperature. With this technique, no assumptions regarding the magnitude of the convective heat transfer coefficient are made. Thus, the probe can operate successfully in unsteady compressible flows of arbitrary composition and high free-stream turbulence levels without a heat transfer law calibration. The operation of the total temperature probe is first demonstrated using a small wind tunnel facility. Based on results from the small wind tunnel tests, it appears that the probe total temperature measurements are accurate to within ±1 K. Experiments using the probe downstream of a high-pressure turbine stage are than described. Both high and low-frequency components of the flow total temperature can be accurately resolved with the present technique. The probe measures a time-averaged flow total temperature that is in good agreement with thermocouple measurements made downstream of the rotor. Frequencies as high as 182 kHz have been detected in the spectral analysis of the heat flux signals from the total probe. Through comparison with fast-response aerodynamic probe measurements, it is demonstrated that the current measurement location, the total temperature fluctuations arise mainly due to the isentropic extraction of work by the turbine. The present total temperature probe is demonstrated to be an accurate, robust, fast-response device that is suitable for operation in a turbomachinery environment.

A Fast-Response High Spatial Resolution Total Temperature Probe Using a Pulsed Heating Technique

1997 ◽  
Author(s):  
D. R. Buttsworth ◽  
T. V. Jones
Keyword(s):  
Thin Film ◽  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Spatial Resolution ◽  
High Spatial Resolution ◽  
Convective Heat Transfer Coefficient ◽  
Fast Response ◽  
Temperature Probe ◽  
Total Temperature

This paper discusses the operation of a fast-response total temperature probe based on transient thin film heat flux gauge technology. The probe utilizes two thin film gauges located close to the stagnation point of a hemispherically-blunted fused quartz cylinder. Development of the present total temperature probe was motivated by the need for a fast-response device with a high spatial resolution. The diameter of the probe was 2.8 mm and the two films were separated by a distance of less than 1 mm. Measurement of the flow total temperature requires the films to operate at different temperatures. In the present work, the temperature difference was generated using a current pulse (approximately 70 mA with a duration of around 1 s) to heat one of the thin film resistance gauges. With this technique, temperature differences between the hot and cold films of around 120 K were achieved. The interpretation of the transient surface temperature measurements is discussed, and the validity and utility of the technique are demonstrated with reference to total temperature and convective heat transfer coefficient measurements in a compressible free jet. The results demonstrate that accurate total temperature and convective heat transfer coefficient measurements with high spatial and temporal resolution can be obtained with the present device.

A Fast-Response High Spatial Resolution Total Temperature Probe Using a Pulsed Heating Technique

1998 ◽  
Vol 120 (3) ◽  
pp. 601-607 ◽  
Author(s):  
D. R. Buttsworth ◽  
T. V. Jones
Keyword(s):  
Thin Film ◽  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Spatial Resolution ◽  
High Spatial Resolution ◽  
Convective Heat Transfer Coefficient ◽  
Fast Response ◽  
Temperature Probe ◽  
Total Temperature

This paper discusses the operation of a fast-response total temperature probe based on transient thin film heat flux gage technology. The probe utilizes two thin film gages located close to the stagnation point of a hemispherically blunted fused quartz cylinder. Development of the present total temperature probe was motivated by the need for a fast-response device with a high spatial resolution. The diameter of the probe was 2.8 mm and the two films were separated by a distance of less than 1 mm. Measurement of the flow total temperature requires the films to operate at different temperatures. In the present work, the temperature difference was generated using a current pulse (approximately 70 mA with a duration of around 1 s) to heat one of the thin film resistance gages. With this technique, temperature differences between the hot and cold films of around 120 K were achieved. The interpretation of the transient surface temperature measurements is discussed, and the validity and utility of the technique are demonstrated with reference to total temperature and convective heat transfer coefficient measurements in a compressible free jet. The results demonstrate that accurate total temperature and convective heat transfer coefficient measurements with high spatial and temporal resolution can be obtained with the present device.

scholarly journals Unsteady Total Temperature Measurements Downstream of a High Pressure Turbine

1997 ◽  
Author(s):  
D. R. Buttsworth ◽  
T. V. Jones ◽  
K. S. Chana
Keyword(s):  
Heat Transfer ◽  
High Pressure ◽  
Wind Tunnel ◽  
Convective Heat Transfer Coefficient ◽  
Fast Response ◽  
Temperature Measurements ◽  
High Pressure Turbine ◽  
Response Device ◽  
Temperature Probe ◽  
Total Temperature

An experimental technique for the measurement of flow total temperature in a turbine facility is demonstrated. Two thin film heat transfer gauges located at the stagnation point of fused quartz substrates are operated at different temperatures in order to determine the flow total temperature. With this technique, no assumptions regarding the magnitude of the convective heat transfer coefficient are made. Thus, the probe can operate successfully in unsteady compressible flows of arbitrary composition and high free-stream turbulence levels without a heat transfer law calibration. The operation of the total temperature probe is first demonstrated using a small wind tunnel facility. Based on results from the small wind tunnel tests, it appears that the probe total temperature measurements are accurate to within ± 1K. Experiments using the probe downstream of a high pressure turbine stage are then described. Both high and low frequency components of the flow total temperature can be accurately resolved with the present technique. The probe measures a time-averaged flow total temperature that is in good agreement with thermocouple measurements made downstream of the rotor. Frequencies as high as 182 kHz have been detected in the spectral analysis of the heat flux signals from the total temperature probe. Through comparison with fast-response aerodynamic probe measurements, it is demonstrated that at the current measurement location, the total temperature fluctuations arise mainly due to the isentropic extraction of work by the turbine. The present total temperature probe is demonstrated to be an accurate, robust, fast-response device that is suitable for operation in a turbomachinery environment.

Comparison Between the Effects of Zero and Non-Zero Flow Acceleration on the Entropy Wave Decay: An Experimental Study

2021 ◽  
Vol 143 (11) ◽  
Author(s):  
S. M. Hosseinalipour ◽  
E. Rahmani ◽  
A. Fattahi
Keyword(s):  
Hot Spot ◽  
Theoretical Models ◽  
Fast Response ◽  
Effective Length ◽  
Combustion Instabilities ◽  
Convergent Nozzle ◽  
Flow Acceleration ◽  
Wave Decay ◽  
Accelerated Flow ◽  
Effective Length Method

Abstract Entropy wave, as the convecting hot spot, is one of the sources of combustion instabilities, which is less explored through the literature. Convecting in a highly turbulent flow of a combustor, entropy waves may experience some levels of dissipation and deformation. In spite of some earlier investigations in the zero acceleration flow, the extent of the wave decay has not been clear yet. Further, there exist no results upon the wave decay in non-zero accelerated flows. This is of crucial importance, as the wave passes through the end nozzle of the combustor or gas turbine stages. The current experiment, therefore, compares the wave decay in both flow of constant and variable bulk velocity, meaning, respectively, a uniform pipe and a convergent nozzle. The comparison will aid the theoretical models to reduce complexity by simplifying the relations of non-zero acceleration flow to those of no acceleration, as followed by the earlier effective-length method. Reynolds number and inlet turbulence intensity are considered as the governing hydrodynamic parameters for both investigated flows. The entropy wave is generated by an electrical heater module and detected using fast-response thermocouples. The results show that the entropy wave variation is point-wise and frequency-dependent. The accelerated flow of the nozzle is generally found to be more dissipative in comparison with the zero acceleration flow.

scholarly journals Eruptive Styles Recognition Using High Temporal Resolution Geostationary Infrared Satellite Data

2019 ◽  
Vol 11 (6) ◽  
pp. 669 ◽  
Author(s):  
Valerio Lombardo ◽  
Stefano Corradini ◽  
Massimo Musacchio ◽  
Malvina Silvestri ◽  
Jacopo Taddeucci
Keyword(s):  
Temporal Resolution ◽  
Hot Spot ◽  
High Temporal Resolution ◽  
Spot Detection ◽  
Infrared Imager ◽  
Mt Etna ◽  
Flow Through ◽  
Radiance Distribution ◽  
Strombolian Explosions ◽  
Infrared Data

The high temporal resolution of the Spinning Enhanced Visible and InfraRed Imager (SEVIRI) instrument aboard Meteosat Second Generation (MSG) provides the opportunity to investigate eruptive processes and discriminate different styles of volcanic activity. To this goal, a new detection method based on the wavelet transform of SEVIRI infrared data is proposed. A statistical analysis is performed on wavelet smoothed data derived from SEVIRI Mid-Infrared( MIR) radiances collected from 2011 to 2017 on Mt Etna (Italy) volcano. Time-series analysis of the kurtosis of the radiance distribution allows for reliable hot-spot detection and precise timing of the start and end of eruptive events. Combined kurtosis and gradient trends allow for discrimination of the different activity styles of the volcano, from effusive lava flow, through Strombolian explosions, to paroxysmal fountaining. The same data also allow for the prediction, at the onset of an eruption, of what will be its dominant eruptive style at later stages. The results obtained have been validated against ground-based and literature data.

scholarly journals Characterization of Periodic Incoming Wakes in a Low-Pressure Turbine Cascade Test Section by Means of a Fast-Response Single Sensor Virtual Three-Hole Probe

2019 ◽  
Vol 4 (3) ◽  
pp. 26
Author(s):  
Julien Clinckemaillie ◽  
Tony Arts
Keyword(s):  
Total Pressure ◽  
High Speed ◽  
Control Volume ◽  
Low Pressure ◽  
Fast Response ◽  
Pressure Probe ◽  
Flow Angle ◽  
Low Pressure Turbine ◽  
Wide Range ◽  
Good Agreement

This paper aims at evaluating the characteristics of the wakes periodically shed by the rotating bars of a spoked-wheel type wake generator installed upstream of a high-speed low Reynolds linear low-pressure turbine blade cascade. Due to the very high bar passing frequency obtained with the rotating wake generator (fbar = 2.4−5.6 kHz), a fast-response pressure probe equipped with a single 350 mbar absolute Kulite sensor has been used. In order to measure the inlet flow angle fluctuations, an angular aerodynamic calibration of the probe allowed the use of the virtual three-hole mode; additionally, yielding yaw corrected periodic total pressure, static pressure and Mach number fluctuations. The results are presented for four bar passing frequencies (fbar = 2.4/3.2/4.6/5.6 kHz), each tested at three isentropic inlet Mach numbers M1,is = 0.26/0.34/0.41 and for Reynolds numbers varying between Re1,is = 40,000 and 58,000, thus covering a wide range of engine representative flow coefficients (ϕ = 0.44−1.60). The measured wake characteristics show fairly good agreement with the theory of fixed cylinders in a cross-flow and the evaluated total pressure losses and flow angle variations generated by the rotating bars show fairly good agreement with theoretical results obtained from a control volume analysis.

Modeling and Experimental Validation of a Reed Check Valve for Hydraulic Applications

2016 ◽  
Author(s):  
Anthony L. Knutson ◽  
James D. Van de Ven
Keyword(s):  
Internal Combustion Engines ◽  
Check Valve ◽  
Maximum Error ◽  
Fast Response ◽  
Single Element ◽  
Hydraulic Systems ◽  
Test Bed ◽  
Experimental Conditions ◽  
Wide Range ◽  
Reed Valve

Reed valves are a type of check valve commonly found in a wide range of applications including air compressors, internal combustion engines, and even the human heart. While reed valves have been studied extensively in these applications, published research on the modeling and application of reed valves in hydraulic systems is severely lacking. Because the spring and mass components of a reed valve are contained in a single element, it is light and compact compared to traditional disc, poppet, or ball style check valves. These advantages make reed valves promising for use in high frequency applications such as piston pumps, switch-mode hydraulics, and digital hydraulics. Furthermore, the small size and fast response of reed valves provide an opportunity to design pumps capable of operating at higher speeds and with lower dead volumes, thus increasing efficiency and power density. In this paper, a modeling technique for reed valves is presented and validated in a hydraulic piston pump test bed. Excellent agreement between modeled and experimentally measured reed valve opening is demonstrated. Across the range of experimental conditions, the model predicts the pump delivery with an error typically less than 1% with a maximum error of 2.2%.

An Insight into the Features of the OAO-C Thermal Design

1973 ◽  
Vol 95 (4) ◽  
pp. 1039-1047 ◽  
Author(s):  
H. Fine ◽  
J. Quadrini ◽  
S. Ollendorf
Keyword(s):  
Thermal Control ◽  
Astronomical Observatory ◽  
Thermal Design ◽  
Test Bed ◽  
Large Space ◽  
Flight Data ◽  
The Earth ◽  
Ground Test ◽  
Earth Observation Satellite ◽  
Insight Into

The Orbiting Astronomical Observatory (OAO)-C was successfully launched into 400-nautical mile circular orbit on August 21, 1972. For this spacecraft, a unique sensitivity approach to the thermal design was developed which resulted in a predictal design—the merits of which should be considered for application on future spacecra. The OAO-C is also serving as a test bed for the evaluation of thermal control hardware. To provide flight data for space program applications, experiments for a new coating and four different heat pipe designs are on this spacecraft. The data derived from OAO-C will be extremely valuable for such future programs as the Large Space Telescope (LST) and the Earth Observation Satellite (EOS). This paper will describe the detailed of the sensitivity design approach and thermal control hardware. For all aspects discussed, a comparison of pertinent analysis, ground test data, and flight data [1] will be given.

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