Stagnation Temperature Measurements in a Shock-Tunnel Facility Using Laser-Induced Grating Spectroscopy

2018 ◽  
Vol 32 (1) ◽  
pp. 226-236 ◽  
Author(s):  
Claudio Selcan ◽  
Tobias Sander ◽  
Philipp Altenhöfer ◽  
Fabian Koroll ◽  
Christian Mundt
Keyword(s):  
Shock Tunnel ◽  
Temperature Measurements ◽  
Stagnation Temperature ◽  
Grating Spectroscopy

scholarly journals Time-Resolved On-Axis Spectroscopic Stagnation Temperature Measurements in Shock Tunnel Flows

2019 ◽  
Vol 3 (2) ◽  
pp. 6
Author(s):  
Hartmut Borchert ◽  
Stefan Brieschenk ◽  
Berthold Sauerwein
Keyword(s):  
Shock Tunnel ◽  
Temperature Measurements ◽  
Stagnation Temperature ◽  
Time Resolved

scholarly journals In-Cylinder Temperature Measurements Using Laser Induced Grating Spectroscopy and Two-Colour PLIF

2017 ◽  
Vol 10 (4) ◽  
pp. 2191-2201 ◽  
Author(s):  
Blane Scott ◽  
Christopher Willman ◽  
Ben Williams ◽  
Paul Ewart ◽  
Richard Stone ◽  
...  
Keyword(s):  
Temperature Measurements ◽  
Grating Spectroscopy

scholarly journals Impact of Flow Unsteadiness on Steady-State Gas-Path Stagnation Temperature Measurements

2018 ◽  
Vol 140 (12) ◽  
Author(s):  
Clare Bonham ◽  
Mark Brend ◽  
Adrian Spencer ◽  
Katsu Tanimizu ◽  
Dylan Wise
Keyword(s):  
Steady State ◽  
Unsteady Flows ◽  
Temperature Measurements ◽  
Conductive Heat ◽  
Calibration Data ◽  
Measured Temperature ◽  
Stagnation Temperature ◽  
Post Test ◽  
Mach Numbers ◽  
The Impact

Steady-state stagnation temperature probes are used during gas turbine engine testing as a means of characterizing turbomachinery component performance. The probes are located in the high-velocity gas-path, where temperature recovery and heat transfer effects cause a shortfall between the measured temperature and the flow stagnation temperature. To improve accuracy, the measurement shortfall is corrected post-test using data acquired at representative Mach numbers in a steady aerodynamic calibration facility. However, probes installed in engines are typically subject to unsteady flows, which are characterized by periodic variations in Mach number and temperature caused by the wakes shed from upstream blades. The present work examines the impact of this periodic unsteadiness on stagnation temperature measurements by translating probes between jets with dissimilar Mach numbers. For conventional Kiel probes in unsteady flows, a greater temperature measurement shortfall is recorded compared to equivalent steady flows, which is related to greater conductive heat loss from the temperature sensor. This result is important for the application of post-test corrections, since an incorrect value will be applied using steady calibration data. A new probe design with low susceptibility to conductive heat losses is therefore developed, which is shown to deliver the same performance in both steady and unsteady flows. Measurements from this device can successfully be corrected using steady aerodynamic calibration data, resulting in improved stagnation temperature accuracy compared to conventional probe designs. This is essential for resolving in-engine component performance to better than ±0.5% across all component pressure ratios.

A Novel Technique for Measuring Stagnation Quantities and Gas Composition in High Temperature Flows

2010 ◽  
Author(s):  
Michela Massini ◽  
Robert J. Miller ◽  
Howard P. Hodson ◽  
Nick Collings
Keyword(s):  
High Temperature ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Gas Turbines ◽  
Stagnation Pressure ◽  
Temperature Measurements ◽  
Stagnation Temperature ◽  
Gas Composition ◽  
Reference Measurements

A new probe has been developed to measure the time averaged stagnation temperature, stagnation pressure and gas composition. This probe can be used in the high temperature regions of gas turbines, including downstream of the combustor and in the first stages of the high pressure turbines, as well as in other environments. The principal benefits of the new probe are that it overcomes the limitations of the standard methods that are used to measure temperature in high temperature environments and that it replaces three separate probes, for the three quantities mentioned above, with one single probe. A novel method of measuring temperature is used, which improves upon the accuracy of thermocouples and increases the temperature operating range. The probe consists of a choked nozzle placed in the hot flow at the point of interest. The working principle is based on the theory that for a choked nozzle, there is a fixed relationship between the stagnation quantities, the gas characteristics and the mass flow rate through the nozzle. The probe has an aspirated phase, where the gas composition and the mass flow rate are measured and a stagnated phase, where the stagnation pressure is measured. The stagnation temperature is determined from the above quantities. The operating principle has been proven valid through laboratory and rig tests. The probe has been successfully tested in a Rolls-Royce Viper engine up to 1000K and 2 bar and in a combustor rig up to 1800K and 4 bars. Measurements of stagnation temperature, stagnation pressure and gas compositions for these tests are presented in the paper and are compared with reference measurements. The accuracy of stagnation pressure and gas composition measurements is equal to the accuracy achievable with techniques that are commonly used in gas turbines. The estimated achievable accuracy of the aspirated probe in terms of temperature measurements is ±0.6%, i.e. ±10K at 1800K, which improves upon the accuracy of temperature measurements performed with standard thermocouples at the same temperatures, the uncertainty of which could be as high as ±2%.

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