Unsteady simulation of flow and heat transfer in a transonic turbine stage under non-uniform inlet conditions

2021 ◽  
Vol 129 ◽  
pp. 105660
Author(s):  
Zakaria Mansouri
Keyword(s):  
Heat Transfer ◽  
Turbine Stage ◽  
Flow And Heat Transfer ◽  
Unsteady Simulation ◽  
Transonic Turbine ◽  
Inlet Conditions

3-D Unsteady Simulation of a Modern High Pressure Turbine Stage Using Phase Lag Periodicity: Analysis of Flow and Heat Transfer

2009 ◽  
Author(s):  
Vikram Shyam ◽  
Ali Ameri ◽  
Daniel F. Luk ◽  
Jen-Ping Chen
Keyword(s):  
Heat Transfer ◽  
Leading Edge ◽  
Phase Lag ◽  
Turbine Stage ◽  
System A ◽  
Flow And Heat Transfer ◽  
Periodicity Analysis ◽  
Unsteady Simulation ◽  
Steady Simulation ◽  
Wake Passing

Unsteady 3-D RANS simulations have been performed on a highly loaded transonic turbine stage and results are compared to steady calculations as well as experiment. A low Reynolds number k-ε turbulence model is employed to provide closure for the RANS system. A phase-lag boundary condition is used in the periodic direction. This allows the unsteady simulation to be performed by using only one blade from each of the two rows. The objective of this paper is to study the effect of unsteadiness on rotor heat transfer and to glean any insight into unsteady flow physics. The role of the stator wake passing on the pressure distribution at the leading edge is also studied. The simulated heat transfer and pressure results agreed favorably with experiment. The time-averaged heat transfer predicted by the unsteady simulation is higher than the heat transfer predicted by the steady simulation everywhere except at the leading edge. The shock structure formed due to stator-rotor interaction was analyzed. Heat transfer and pressure at the hub and casing were also studied. Thermal segregation was observed that leads to the heat transfer patterns predicted by steady and unsteady simulations to be different.

Numerical Investigation on Unsteady Effects of Hot Streak on Flow and Heat Transfer in a Turbine Stage

2008 ◽  
Author(s):  
Bai-Tao An ◽  
Jian-Jun Liu ◽  
Hong-De Jiang
Keyword(s):  
Heat Transfer ◽  
Rotor Blade ◽  
Heat Load ◽  
Leading Edge ◽  
Turbine Stage ◽  
Characteristic Analysis ◽  
Flow And Heat Transfer ◽  
Total Temperature ◽  
Inlet Conditions ◽  
Hot Streak

This paper presents a detailed flow and heat transfer characteristic analysis on gas turbine first stage turbine under hot streak inlet conditions. Two kinds of inlet total temperature conditions are specified at the turbine stage inlet. The first is uniform inlet total temperature, and the second is hot streak 2D total temperature contour. The two kinds of inlet conditions have the same mass-averaged total temperature, and the same uniform inlet total pressure. The hot streak total temperature contours are obtained according to the exit shape of an annular-can combustor. The ratio of the highest total temperature in the hot streak to the mass-averaged total temperature is about 1.23, and one hot streak corresponds to two vane passages and four blade passages. Six hot streak circumferential positions relative to the vane 1 leading edge varied from −2% to 81% pitch are computed and analyzed. Results show that hot streak obviously increases the non-uniform degree of vane heat load in comparison with the uniform total temperature inlet condition. The change of hot streak circumferential position leads to the circumferential parameter variation at stator exit, and also leads to different transient periodic fluctuating characteristics of heat load and pressure on rotor blade surface. The hot streak of relative pitch at 65% obtains similar heat load for the two vanes corresponding to one hot streak and small fluctuation of the averaged heat load on rotor blade.

Numerical Investigation on Unsteady Effects of Hot Streak on Flow and Heat Transfer in a Turbine Stage

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
Bai-Tao An ◽  
Jian-Jun Liu ◽  
Hong-De Jiang
Keyword(s):  
Heat Transfer ◽  
Rotor Blade ◽  
Heat Load ◽  
Leading Edge ◽  
Turbine Stage ◽  
Characteristic Analysis ◽  
Flow And Heat Transfer ◽  
Total Temperature ◽  
Inlet Conditions ◽  
Hot Streak

This paper presents a detailed flow and heat transfer characteristic analysis on gas turbine first-stage turbine under hot streak inlet conditions. Two kinds of inlet total temperature conditions are specified at the turbine stage inlet. The first is uniform inlet total temperature, and the second is hot streak 2D total temperature contour. The two kinds of inlet conditions have the same mass-averaged total temperature and the same uniform inlet total pressure. The hot streak total temperature contours are obtained according to the exit shape of an annular-can combustor. The ratio of the highest total temperature in the hot streak to the mass-averaged total temperature is about 1.23, and one hot streak corresponds to two vane passages and four blade passages. Six hot streak circumferential positions relative to the Vane 1 leading edge varied from −2% to 81% pitch are computed and analyzed. The results show that hot streak obviously increases the nonuniform degree of vane heat load in comparison with the uniform total temperature inlet condition. The change in hot streak circumferential position leads to the circumferential parameter variation at stator exit and also leads to different transient periodic fluctuating characteristics of heat load and pressure on the rotor blade surface. The hot streak of relative pitch at 65% obtains a similar heat load for the two vanes corresponding to one hot streak and small fluctuation in the averaged heat load on the rotor blade.

scholarly journals Unsteady Simulation of a Transonic Turbine Stage with Focus on Turbulence Prediction

2021 ◽  
Vol 6 (3) ◽  
pp. 36
Author(s):  
Wolfgang Sanz ◽  
David Scheier
Keyword(s):  
Boundary Conditions ◽  
Secondary Flows ◽  
Correct Prediction ◽  
Turbine Stage ◽  
Free Stream Turbulence ◽  
Eddy Viscosity Model ◽  
Unsteady Simulation ◽  
Unsteady Rans ◽  
Transonic Turbine ◽  
Inlet Conditions

The flow in a transonic turbine stage still poses a high challenge for the correct prediction of turbulence using an eddy viscosity model. Therefore, an unsteady RANS simulation with the k-ω SST model, based on a preceding study of turbulence inlet conditions, was performed to see if this can improve the quality of the flow and turbulence prediction of an experimentally investigated turbine flow. Unsteady Q3D results showed that none of the different turbulence boundary conditions could predict the free-stream turbulence level and the maximum values correctly. Luckily, the influence of the boundary conditions on the velocity field proved to be small. The qualitative prediction of the complex secondary flows is good, but there is lacking agreement in the prediction of turbulence generation and destruction.

Numerical Simulations of Unsteady Fluid Flow and Heat Transfer in a Transonic Turbine Stage

2006 ◽  
Author(s):  
F. Mumic ◽  
B. Sunden
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Numerical Study ◽  
Time Discretization ◽  
Implicit Time ◽  
Turbine Stage ◽  
Flow And Heat Transfer ◽  
Unsteady Fluid Flow ◽  
Transonic Turbine ◽  
Unsteady Fluid

In this work, a numerical study has been performed to simulate the unsteady fluid flow and heat transfer in a transonic high-pressure turbine stage. The main objective of this study is to understand the unsteady flow field and heat transfer in a single transonic turbine stage using an unsteady structured Navier-Stokes solver. For the time accurate computation, a fully implicit time discretization, dual-time stepping, is performed. The results of the CFD simulations are compared with experimental heat transfer and aerodynamic results available for the so-called MT1 turbine stage. The predicted heat transfer and static pressure distributions show reasonable agreement with experimental data. In particular, the results show significant fluctuations in heat transfer and pressure at midspan on the rotor blade, and that the rotor has a limited influence on the heat transfer to the NGV at mid span.

Transonic Turbine Stage Heat Transfer Investigation in Presence of Strong Shocks

2008 ◽  
Vol 130 (3) ◽  
Author(s):  
A. de la Loma ◽  
G. Paniagua ◽  
D. Verrastro ◽  
P. Adami
Keyword(s):  
Heat Transfer ◽  
Rotor Blade ◽  
Shock Interaction ◽  
Turbine Stage ◽  
Test Rig ◽  
Unsteady Heat Transfer ◽  
Tube Test ◽  
Stator Blade ◽  
Transonic Turbine ◽  
Layered Thin Film

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.

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.

scholarly journals Endwall Heat Transfer Measurements in a Transonic Turbine Cascade

1998 ◽  
Vol 120 (2) ◽  
pp. 305-313 ◽  
Author(s):  
P. W. Giel ◽  
D. R. Thurman ◽  
G. J. Van Fossen ◽  
S. A. Hippensteele ◽  
R. J. Boyle
Keyword(s):  
Heat Transfer ◽  
Flow Field ◽  
Turbine Blade ◽  
Large Scale ◽  
Model Verification ◽  
Quality Data ◽  
Free Stream Turbulence ◽  
Transonic Turbine ◽  
Mach Numbers ◽  
Inlet Conditions

Turbine blade endwall heat transfer measurements are presented for a range of Reynolds and Mach numbers. Data were obtained for Reynolds numbers based on inlet conditions of 0.5 and 1.0 × 106, for isentropic exit Mach numbers of 1.0 and 1.3, and for free-stream turbulence intensities of 0.25 and 7.0 percent. Tests were conducted in a linear cascade at the NASA Lewis Transonic Turbine Blade Cascade Facility. The test article was a turbine rotor with 136 deg of turning and an axial chord of 12.7 cm. The large scale allowed for very detailed measurements of both flow field and surface phenomena. The intent of the work is to provide benchmark quality data for CFD code and model verification. The flow field in the cascade is highly three dimensional as a result of thick boundary layers at the test section inlet. Endwall heat transfer data were obtained using a steady-state liquid crystal technique.

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