A Novel Single-Passage Transonic Wind Tunnel for Turbine-Vane Film Cooling

2020 ◽  
Vol 142 (7) ◽  
Author(s):  
Mohamed Qenawy ◽  
Lin Yuan ◽  
Yingzheng Liu ◽  
Di Peng ◽  
Xin Wen ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
Film Cooling ◽  
Three Dimensional ◽  
Fast Response ◽  
Low Flow ◽  
Wind Tunnels ◽  
Single Passage ◽  
Turbine Vane ◽  
Response Pressure ◽  
Transonic Wind Tunnel

Abstract Wind-tunnel testing of turbines cascade is an important technique for quantifying the realistic conditions of turbine-vane film cooling. However, the complex and expensive facilities needed for the multipassage design of such wind tunnels have prompted the introduction of the single-passage design strategy. In this contribution, detailed procedures for building a novel single-passage transonic wind-tunnel using additive manufacturing are presented. In addition, the detailed flow structure caused by the passage was investigated. The proposed design was evaluated step-by-step using an integrated model that successively comprised two-dimensional (2D) periodic passage simulation, 2D single-passage simulation, three-dimensional (3D) single-passage simulation, construction, and testing. The proposed design was found to achieve flow periodicity at transonic flow conditions with relatively low-flow consumption. The results were validated by comparison to the available literature data. In addition, an endwall-cooling configuration was successfully deployed using fast-response pressure-sensitive paint (fast-PSP). This study, combined with the help of commercial software and 3D printing, shed light upon strategies for time- and cost-reduction in linear cascade design, which could benefit the turbomachinery community.

The Effect of Vane Clocking on the Unsteady Flowfield in a One and a Half Stage Transonic Turbine

2007 ◽  
Author(s):  
O. Schennach ◽  
R. Pecnik ◽  
B. Paradiso ◽  
E. Go¨ttlich ◽  
A. Marn ◽  
...  
Keyword(s):  
Laser Doppler Velocimetry ◽  
Three Dimensional ◽  
Fast Response ◽  
Navier Stokes ◽  
Doppler Velocimetry ◽  
Pressure Transducers ◽  
Wake Interactions ◽  
Transonic Turbine ◽  
Response Pressure ◽  
Vane Clocking

The current paper presents the results of numerical and experimental clocking investigations performed in a high-pressure transonic turbine with a downstream vane row. The objective was a detailed analysis of shock and wake interactions in such a 1.5 stage machine while clocking the vanes. Therefore a transient 3D-Navier Stokes calculation was done for two clocking positions and the three dimensional results are compared with Laser-Doppler-Velocimetry measurements at midspan. Additionally the second vane was equipped with fast response pressure transducers to record the instantaneous surface pressure for 20 different clocking positions at midspan.

scholarly journals A Three-Dimensional Coupled Internal/External Simulation of a Film-Cooled Turbine Vane

1999 ◽  
Author(s):  
James D. Heidmann ◽  
David L. Rigby ◽  
Ali A. Ameri
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Film Cooling ◽  
Three Dimensional ◽  
High Heat ◽  
Operating Conditions ◽  
High Heat Flux ◽  
Nasa Lewis Research ◽  
Turbine Vane ◽  
Film Cooling Holes

A three-dimensional Navier-Stokes simulation has been performed for a realistic film-cooled turbine vane using the LeRC-HT code. The simulation includes the flow regions inside the coolant plena and film cooling holes in addition to the external flow. The vane is the subject of an upcoming NASA Lewis Research Center experiment and has both circular cross-section and shaped film cooling holes. This complex geometry is modeled using a multi-block grid which accurately discretizes the actual vane geometry including shaped holes. The simulation matches operating conditions for the planned experiment and assumes periodicity in the spanwise direction on the scale of one pitch of the film cooling hole pattern. Two computations were performed for different isothermal wall temperatures, allowing independent determination of heat transfer coefficients and film effectiveness values. The results indicate separate localized regions of high heat flux in the showerhead region due to low film effectiveness and high heat transfer coefficient values, while the shaped holes provide a reduction in heat flux through both parameters. Hole exit data indicate rather simple skewed profiles for the round holes, but complex profiles for the shaped holes with mass fluxes skewed strongly toward their leading edges.

Design and Testing of a Miniaturized Five-Hole Fast Response Pressure Probe With Large Frequency Bandwidth and High Angular Sensitivity

2019 ◽  
Vol 141 (10) ◽  
Author(s):  
Elissavet Boufidi ◽  
Marco Alati ◽  
Fabrizio Fontaneto ◽  
Sergio Lavagnoli
Keyword(s):  
Dynamic Response ◽  
Three Dimensional ◽  
Experimental Tests ◽  
Fast Response ◽  
Pressure Probe ◽  
Probe Design ◽  
Directional Sensitivity ◽  
Angular Sensitivity ◽  
Numerical Predictions ◽  
Response Pressure

Abstract A miniaturized five-hole fast response pressure probe is presented, and the methods for the aerodynamic design and performance characterization are explained in detail. The probe design is aimed for three-dimensional (3D) time-resolved measurements in turbomachinery flows, therefore requiring high frequency response and directional sensitivity. It features five encapsulated piezoresistive pressure transducers, recessed inside the probe hemispherical head. Theoretical and numerical analyses are carried out to estimate the dynamic response of the pressure tap line-cavity systems and to investigate unsteady effects that can influence the pressure readings. A prototype is manufactured and submitted to experimental tests that demonstrate performance in line with the theoretical and numerical predictions of the dynamic response: the natural frequency of the central and lateral taps extends to 200 and 25 kHz, respectively. An aerodynamic calibration is also performed at different Reynolds and Mach numbers. The probe geometry offers a good angular sensitivity in a ± 30 deg incidence range, while a frequency analysis reveals the presence of pressure oscillations related to vortex shedding at large angles of attack.

An Experimental Investigation of the Flow Through an Axial-Flow Pump

1995 ◽  
Vol 117 (3) ◽  
pp. 485-490 ◽  
Author(s):  
W. C. Zierke ◽  
W. A. Straka ◽  
P. D. Taylor
Keyword(s):  
Large Scale ◽  
Three Dimensional ◽  
Axial Flow ◽  
Fast Response ◽  
Complex Flow ◽  
Penn State ◽  
Response Pressure ◽  
Axial Flow Pump ◽  
Scale Experiment ◽  
High Reynolds

The high Reynolds number pump (HIREP) facility at ARL Penn State has been used to perform a low-speed, large-scale experiment of the incompressible flow of water through a two-blade-row turbomachine. The objectives of this experiment were to provide a database for comparison with three-dimensional, turbulent flow computations, to evaluate engineering models, and to improve our physical understanding of many of the phenomena involved in this complex flow field. This summary paper briefly describes the experimental facility, as well as the experimental techniques—such as flow visualization, static-pressure measurements, laser Doppler velocimetry, and both slow- and fast-response pressure probes. Then, proceeding from the inlet to the exit of the pump, the paper presents highlights of experimental measurements and data analysis, giving examples of measured physical phenomena such as endwall boundary layers, separation regions, wakes, and secondary vortical structures. In conclusion, this paper provides a synopsis of a well-controlled, larger scope experiment that should prove helpful to those who wish to use the database.

Design and Testing of a Miniaturized Five-Hole Fast Response Pressure Probe With Large Frequency Bandwidth and High Angular Sensitivity

2019 ◽  
Author(s):  
Elissavet Boufidi ◽  
Marco Alati ◽  
Fabrizio Fontaneto ◽  
Sergio Lavagnoli
Keyword(s):  
Dynamic Response ◽  
Three Dimensional ◽  
Experimental Tests ◽  
Fast Response ◽  
Pressure Probe ◽  
Probe Design ◽  
Directional Sensitivity ◽  
Angular Sensitivity ◽  
Numerical Predictions ◽  
Response Pressure

Abstract A miniaturized five-hole fast response pressure probe is presented and the methods for the aerodynamic design and characterization performance are explained in detail. The probe design is aimed for three-dimensional time-resolved measurements in turbomachinery flows, therefore requiring high frequency response and directional sensitivity. It features five encapsulated piezoresistive pressure transducers, recessed inside the probe hemispherical head. Theoretical and numerical analyses are carried out to estimate the dynamic response of the pressure tap line-cavity systems and to investigate unsteady effects that can influence the pressure readings. A prototype is manufactured and submitted to experimental tests that demonstrate performance in line with the theoretical and numerical predictions of the dynamic response: the natural frequency of the central and lateral taps extend to 25 kHz and 200 kHz respectively. An aerodynamic calibration is also performed at different Reynolds and Mach numbers. The probe geometry offers a good angular sensitivity in a ±30° incidence range, while a frequency analysis reveals the presence of pressure oscillations related to vortex shedding at large angles of attack.

Time-Accurate Evaluation of Film Cooling Jet Characteristics for Plenum and Crossflow Coolant Supplies

2019 ◽  
Author(s):  
Spencer J. Sperling ◽  
Randall M. Mathison
Keyword(s):  
Film Cooling ◽  
Momentum Flux ◽  
Flux Ratio ◽  
Fast Response ◽  
Mode Shapes ◽  
Momentum Flux Ratio ◽  
Cooling Hole ◽  
The Difference ◽  
Response Pressure ◽  
Jet Characteristics

Abstract Gas turbine film cooling creates complicated and highly unsteady flow structures. This study seeks to examine the unsteady characteristics created by different film hole inlet geometries using a fast-response pressure sensitive paint (PSP) technique able to capture time-accurate measurements at 2000 frames per second, resolving frequencies up to 1000 Hz. Time accurate and time-averaged measurements are used to evaluate the performance of a plenum-style inlet and a crossflow-style inlet in varying turbulence environments over a flat plate. The results of this study are intended to begin the process of breaking down widely accepted time-averaged film effectiveness contours into the cumulative effects of smaller oscillating cooling jets. Jet behaviors observed in this study include a sweeping oscillation, unsteady attachment and separation from the plate, and time accurate and time average flow bias. The behavior and performance of higher blowing ratio, separated film cooling jets depend heavily on the momentum flux ratio. Crossflow fed cooling holes show bias to the upstream side of the cooling hole with respect to the internal crossflow direction. Plenum fed cooling holes outperform crossflow fed cooling holes, and the difference increases with increasing momentum flux ratio. Cooling hole inlet geometry and momentum flux ratio affect the core of the jet, and freestream turbulence affects the periphery of the jet. Fluctuating frequencies of plenum fed and crossflow fed cooling holes were seen to be influenced by the turbulent velocity fluctuation frequency. The resulting mode shapes showed dominant side-to-side fluctuations for higher turbulence environments and a separation and reattachment motion for lower turbulence environments.

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