Heat Transfer Investigation on a Transonic Turbine Cascade with Pulsating Trailing Edge Cooling

2012 ◽  
Author(s):  
Bayindir Saracoglu ◽  
Guillermo Paniagua
Keyword(s):  
Heat Transfer ◽  
Turbine Cascade ◽  
Trailing Edge ◽  
Transonic Turbine

Unsteady Rotor Heat Transfer in a Transonic Turbine Stage

2002 ◽  
Author(s):  
F. Didier ◽  
R. De´nos ◽  
T. Arts
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Strong Dependence ◽  
Convective Heat Transfer Coefficient ◽  
Operating Conditions ◽  
Turbine Stage ◽  
Trailing Edge ◽  
Time Resolved ◽  
Number Distribution ◽  
Transonic Turbine

This experimental investigation reports the convective heat transfer coefficient around the rotor of a transonic turbine stage. Both time-resolved and time-averaged aspects are addressed. The measurements are performed around the rotor blade at 15%, 50% and 85% span as well as on the rotor tip and the hub platform. Four operating conditions are tested covering two Reynolds numbers and three pressure ratios. The tests are performed in the compression tube turbine test rig CT3 of the von Karman Institute, allowing a correct simulation of the operating conditions encountered in modern aero-engines. The time-averaged Nusselt number distribution shows the strong dependence on both blade Mach number distribution and Reynolds number. The time-resolved heat transfer rate is mostly dictated by the vane trailing edge shock impingement on the rotor boundary layer. The shock passage corresponds to a sudden heat transfer increase. The effects are more pronounced in the leading edge region. The increase of the stage pressure ratio causes a stronger vane trailing edge shock and thus larger heat transfer fluctuations. The influence of the Reynolds number is hardly visible.

Experimental and numerical investigations of trailing edge injection in a transonic turbine cascade

2019 ◽  
Vol 92 ◽  
pp. 258-268 ◽  
Author(s):  
Jie Gao ◽  
Ming Wei ◽  
Weiliang Fu ◽  
Qun Zheng ◽  
Guoqiang Yue
Keyword(s):  
Turbine Cascade ◽  
Trailing Edge ◽  
Numerical Investigations ◽  
Transonic Turbine

Unsteady Rotor Heat Transfer in a Transonic Turbine Stage

2002 ◽  
Vol 124 (4) ◽  
pp. 614-622 ◽  
Author(s):  
F. Didier ◽  
R. De´nos ◽  
T. Arts
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Strong Dependence ◽  
Convective Heat Transfer Coefficient ◽  
Operating Conditions ◽  
Turbine Stage ◽  
Trailing Edge ◽  
Time Resolved ◽  
Number Distribution ◽  
Transonic Turbine

This experimental investigation reports the convective heat transfer coefficient around the rotor of a transonic turbine stage. Both time-resolved and time-averaged aspects are addressed. The measurements are performed around the rotor blade at 15, 50, and 85% span as well as on the rotor tip and the hub platform. Four operating conditions are tested covering two Reynolds numbers and three pressure ratios. The tests are performed in the compression tube turbine test rig CT3 of the von Karman Institute, allowing a correct simulation of the operating conditions encountered in modern aero-engines. The time-averaged Nusselt number distribution shows the strong dependence on both blade Mach number distribution and Reynolds number. The time-resolved heat transfer rate is mostly dictated by the vane trailing edge shock impingement on the rotor boundary layer. The shock passage corresponds to a sudden heat transfer increase. The effects are more pronounced in the leading edge region. The increase of the stage pressure ratio causes a stronger vane trailing edge shock and thus larger heat transfer fluctuations. The influence of the Reynolds number is hardly visible.

Unsteady Effects on Transonic Turbine Blade-Tip Heat Transfer

2012 ◽  
Vol 134 (6) ◽  
Author(s):  
Nicholas R. Atkins ◽  
Steven J. Thorpe ◽  
Roger W. Ainsworth
Keyword(s):  
Heat Transfer ◽  
Flow Field ◽  
Flow Distribution ◽  
Potential Interaction ◽  
Rotor Blades ◽  
Time Varying ◽  
Trailing Edge ◽  
Blade Tip ◽  
Transonic Turbine ◽  
The Impact

In a gas turbine engine the blade tips of the high-pressure turbine are exposed to high levels of convective heat transfer, because of the so-called tip-leakage phenomenon. The blade-lift distribution is known to control the flow distribution in the blade–tip gap. However, the interaction between upstream nozzle guide vanes and the rotor blades produces a time-varying flow field that induces varying flow conditions around the blade and within the tip gap. Extensive measurements of the unsteady blade-tip heat transfer have been made in an engine representative transonic turbine. These include measurements along the mean camber line of the blade tip, which have revealed significant variation in both time-mean and time-varying heat flux. The influences of potential interaction and the vane trailing edge have been observed. Numerical calculations of the turbine stage using a Reynolds-averaged-Navier-Stokes-based computational fluid dynamics code have also been conducted. In combination with the experimental results, these have enabled the time-varying flow field to be probed in the blade-relative frame of reference. This has allowed a deeper analysis of the unsteady heat-transfer data, and the quantification of the impact of vane potential field and vane trailing edge interaction on the tip-region flow and heat transfer. In particular, the separate effects of time-varying flow temperature and heat-transfer coefficient have been established.

Investigations of Transonic Turbine Cascade With High Stagger and Low Solidity

1979 ◽  
Author(s):  
M. Inoue ◽  
S. Yamaguchi ◽  
M. Kuroumaru
Keyword(s):  
Transonic Flow ◽  
Laval Nozzle ◽  
Experimental Studies ◽  
Flow Characteristics ◽  
Chord Length ◽  
Turbine Cascade ◽  
Trailing Edge ◽  
Time Marching ◽  
Shock System ◽  
Transonic Turbine

In order to clarify the transonic flow characteristics of a turbine cascade with high stagger, low solidity and small deflections, experimental studies were carried out by shortening the chord length of a “Laval-nozzle shaped” blade with thick trailing edge. The behavior of the shock system depends on the amount of overlap between the blades. The relations between the behavior and the performances were discussed in detail. The results may be applied to more standard sections. Lastly, validity of an appropriate time marching analysis for the highly staggered cascade was investigated by comparing with the experiment.

scholarly journals Simulation of Trailing Edge Vortex Shedding in a Transonic Turbine Cascade

1996 ◽  
Author(s):  
Tom C. Currie ◽  
William E. Carscallen
Keyword(s):  
Vortex Shedding ◽  
Navier Stokes ◽  
Numerical Dissipation ◽  
Turbine Cascade ◽  
Trailing Edge ◽  
Edge Vortex ◽  
Transonic Turbine ◽  
Exit Mach Number ◽  
Good Agreement

Mid-span losses in the NRC transonic turbine cascade peak at an exit Mach number (M2) of ∼1.0 and then decrease by ∼40% as M2 is increased to the design value of 1.16. Since recent experimental results suggest that the decrease may be related to a reduction in the intensity of trailing edge vortex shedding, both steady and unsteady quasi-3D Navier-Stokes simulations have been performed with a highly refined (unstructured) grid to determine the role of shedding. Predicted shedding frequencies are in good agreement with experiment, indicating the blade boundary layers and trailing edge separated free shear layers have been modelled satisfactorily, but the agreement for base pressures is relatively poor, probably due largely to false entropy created downstream of the trailing edge by numerical dissipation. The results emphasize the importance of accounting for the effect of vortex shedding on base pressure and loss.

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