Effects of Shocks on the Unsteady Heat Transfer in a Film-Cooled Transonic Turbine Cascade

2001 ◽  
Author(s):  
Tom Diller ◽  
Wing Ng ◽  
Andrew Nix
2021 ◽  
Author(s):  
Richard Celestina ◽  
Spencer Sperling ◽  
Louis Christensen ◽  
Randall Mathison ◽  
Hakan Aksoy ◽  
...  

2008 ◽  
Vol 130 (3) ◽  
Author(s):  
A. de la Loma ◽  
G. Paniagua ◽  
D. Verrastro ◽  
P. Adami

This paper reports the external convective heat transfer distribution of a modern single-stage transonic turbine together with the physical interpretation of the different shock interaction mechanisms. The measurements have been performed in the compression tube test rig of the von Karman Institute using single- and double-layered thin film gauges. The three pressure ratios tested are representative of those encountered in actual aeroengines, with M2,is ranging from 1.07 to 1.25 and a Reynolds number of about 106. Three different rotor blade heights (15%, 50%, and 85%) and the stator blade at midspan have been investigated. The measurements highlight the destabilizing effect of the vane left-running shock on the rotor boundary layer. The stator unsteady heat transfer is dominated by the fluctuating right-running vane trailing edge shock at the blade passing frequency.


Author(s):  
A. de la Loma ◽  
G. Paniagua ◽  
D. Verrastro ◽  
P. Adami

This paper reports the external convective heat transfer distribution of a modern single-stage transonic turbine together with the physical interpretation of the different shock interaction mechanisms. The measurements have been performed in the compression tube test rig of the von Karman Institute using single and double-layered thin film gauges. The three pressure ratios tested are representative of those encountered in actual aero-engines, with M2, is ranging from 1.07 to 1.25 and a Reynolds number of about 106. Three different rotor blade heights (15%, 50% and 85%) and the stator blade at mid-span have been investigated. The measurements highlight the destabilizing effect of the vane left running shock on the rotor boundary layer. The stator unsteady heat transfer is dominated by the fluctuating right running vane trailing edge shock at the blade passing frequency.


Author(s):  
William Allan ◽  
Roger Ainsworth ◽  
Steven Thorpe

The unsteady heat transfer measurements about a transonic turbine blade at engine representative Mach and Reynolds numbers are presented. High density, fast response thin film gauges are employed at the mid-height streamline. A description of the novel development of gold gauges together with a brief overview of their calibration and signal processing is presented. Detailed time and phase-averaged measurements have been obtained, providing insight into the role of upstream nozzle guide vane wakes and shock features. These heat transfer results compliment recent fast-response aerodynamic results on this and similar transonic profiles, which highlight the dominance of the upstream vane-rotor interaction over convected wake segments, particularly in light of unsteady turbine blade loading. From a heat transfer standpoint however, whilst the periodic shock events contributed to abrupt, localized heat transfer enhancements, the influence of NGV wake segments on the boundary layer could not be discounted when duration of unsteadiness was considered.


Author(s):  
Reza S. Abhari ◽  
A. H. Epstein

Time-resolved measurements of heat transfer on a fully cooled transonic turbine stage have been taken in a short duration turbine test facility which simulates full engine non-dimensional conditions. The time average of this data is compared to uncooled rotor data and cooled linear cascade measurements made on the same profile. The film cooling reduces the time-averaged heat transfer compared to the uncooled rotor on the blade suction surface by as much as 60%, but has relatively little effect on the pressure surface. The suction surface rotor heat transfer is lower than that measured in the cascade. The results are similar over the central 3/4 of the span implying that the flow here is mainly two-dimensional. The film cooling is shown to be much less effective at high blowing ratios than at low ones. Time-resolved measurements reveal that the cooling, when effective, both reduced the d.c. level of heat transfer and changed the shape of the unsteady waveform. Unsteady blowing is shown to be a principal driver of film cooling fluctuations, and a linear model is shown to do a good job in predicting the unsteady heat transfer. The unsteadiness results in a 12% decrease in heat transfer on the suction surface and a 5% increase on the pressure surface.


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