Detailed Velocity and Turbulence Measurements in an Inclined Large-Scale Film Cooling Array

2013 ◽  
Vol 135 (6) ◽  
Author(s):  
Lamyaa A. El-Gabry ◽  
Douglas R. Thurman ◽  
Philip E. Poinsatte ◽  
James D. Heidmann
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Flow Field ◽  
Film Cooling ◽  
Large Scale ◽  
Field Measurements ◽  
Scale Model ◽  
Data Sets ◽  
Turbulent Dissipation ◽  
Hotwire Anemometry

A large-scale model of an inclined row of film cooling holes is used to obtain detailed surface and flow field measurements that will enable future computational fluid dynamics code development and validation. The model consists of three holes of 1.9-cm diameter that are spaced three hole diameters apart and inclined 30 deg from the surface. The length to diameter ratio of the coolant holes is about 18. Measurements include film effectiveness using IR thermography and near wall thermocouples, heat transfer using liquid crystal thermography, flow field temperatures using a thermocouple, and velocity and turbulence quantities using hotwire anemometry. Results are obtained for blowing ratios of up to 2 in order to capture severe conditions in which the jet is lifted. For purposes of comparison with prior art, measurements of the velocity and turbulence field along the jet centerline are made and compare favorably with two data sets in the open literature thereby verifying the test apparatus and methodology are able to replicate existing data sets. In addition, a computational fluid dynamics model using a two-equation turbulence model is developed, and the results for velocity, turbulent kinetic energy and turbulent dissipation rate are compared with experimentally derived quantities.

Turbulence and Heat Transfer Measurements in an Inclined Large Scale Film Cooling Array: Part I—Velocity and Turbulence Measurements

2011 ◽  
Author(s):  
Lamyaa A. El-Gabry ◽  
Douglas R. Thurman ◽  
Philip E. Poinsatte ◽  
James D. Heidmann
Keyword(s):  
Heat Transfer ◽  
Flow Field ◽  
Film Cooling ◽  
Large Scale ◽  
Field Measurements ◽  
Scale Model ◽  
Liquid Crystal Thermography ◽  
Detailed Surface ◽  
Cooling Hole ◽  
Hotwire Anemometry

A large-scale model of an inclined row of film cooling holes is used to obtain detailed surface and flow field measurements that will enable future computational fluid dynamics code development and validation. The model consists of three holes of 1.9-cm diameter that are spaced 3 hole diameters apart and inclined 30° from the surface. The length to diameter ratio of the coolant holes is about 18. Measurements include film effectiveness using IR thermography and near wall thermocouples, heat transfer using liquid crystal thermography, flow field temperatures using a thermocouple, and velocity and turbulence quantities using hotwire anemometry. Results are obtained for blowing ratios of up to 2 in order to capture severe conditions in which the jet is lifted. This first part of the two-part paper presents the detailed velocity component and turbulence stresses along the centerline of the film-cooling hole and at various streamwise locations.

Combustor Turbine Interface Studies: Part 2 — Flow and Thermal Field Measurements

2002 ◽  
Author(s):  
W. F. Colban ◽  
A. T. Lethander ◽  
K. A. Thole ◽  
G. Zess
Keyword(s):  
Flow Field ◽  
Secondary Flow ◽  
Film Cooling ◽  
Large Scale ◽  
Field Measurements ◽  
Pressure Profile ◽  
Stagnation Line ◽  
Turbine Engine ◽  
Turbine Vane ◽  
Cooling Methods

Most turbine inlet flows resulting from the combustor exit are non-uniform in the near-platform region as a result of cooling methods used for the combustor liner. These cooling methods include injection through film-cooling holes and injection through a slot that connects the combustor and turbine. This paper presents thermal and flow field measurements in the turbine vane passage for a combustor exit flow representative of what occurs in a gas turbine engine. The experiments were performed in a large-scale wind tunnel facility that incorporates combustor and turbine vane models. The measured results for the thermal and flow fields indicate a secondary flow pattern in the vane passage that can be explained by the total pressure profile exiting the combustor. This secondary flow field is quite different than that presented for past studies with an approaching flat plate turbulent boundary layer along the upstream platform. A counter-rotating vortex that is positioned above the passage vortex was identifed from the measurements. Highly turbulent and highly unsteady flow velocities occur at flow impingment locations along the stagnation line.

Combustor Turbine Interface Studies—Part 2: Flow and Thermal Field Measurements

2003 ◽  
Vol 125 (2) ◽  
pp. 203-209 ◽  
Author(s):  
W. F. Colban ◽  
A. T. Lethander ◽  
K. A. Thole ◽  
G. Zess
Keyword(s):  
Flow Field ◽  
Secondary Flow ◽  
Film Cooling ◽  
Large Scale ◽  
Field Measurements ◽  
Pressure Profile ◽  
Stagnation Line ◽  
Turbine Engine ◽  
Turbine Vane ◽  
Cooling Methods

Most turbine inlet flows resulting from the combustor exit are nonuniform in the near-platform region as a result of cooling methods used for the combustor liner. These cooling methods include injection through film-cooling holes and injection through a slot that connects the combustor and turbine. This paper presents thermal and flow field measurements in the turbine vane passage for a combustor exit flow representative of what occurs in a gas turbine engine. The experiments were performed in a large-scale wind tunnel facility that incorporates combustor and turbine vane models. The measured results for the thermal and flow fields indicate a secondary flow pattern in the vane passage that can be explained by the total pressure profile exiting the combustor. This secondary flow field is quite different than that presented for past studies with an approaching flat plate turbulent boundary layer along the upstream platform. A counter-rotating vortex that is positioned above the passage vortex was identified from the measurements. Highly turbulent and highly unsteady flow velocities occur at flow impingement locations along the stagnation line.

Flow Field Measurements on a Large Scale Turbine Cascade With Leading Edge Film Cooling by Two Rows of Holes

1997 ◽  
Author(s):  
Sabine Ardey ◽  
Leonhard Fottner
Keyword(s):  
Flow Field ◽  
Film Cooling ◽  
Gas Turbines ◽  
Large Scale ◽  
Vortex Pair ◽  
Leading Edge ◽  
Field Measurements ◽  
Suction Side ◽  
Pressure Side ◽  
Turbine Cascade

To increase the understanding of the aerodynamic processes dominating the flow field of turbine bladings with leading edge film cooling, isothermal investigations were carried out on a large scale high pressure turbine cascade. Near the stagnation point the blades are equipped with one row of film cooling holes on the suction side and one on the pressure side. Blowing ratio, turbulence intensity, Mach number, and Reynolds number are set to values typically found in modern gas turbines. Experimental data of the cascade flow were obtained by pneumatic probes and static pressure tappings. The flow field was visualized by Schlieren and oil flow techniques. For detailed investigations near the blowing holes the Laser Transit Velocimetry and the three dimensional Hot Wire Anemometry were used. The flow field measurements in the near hole region of the suction side show the typical kidney shaped vortex pair. A local suction peak on the pressure side causes a large recirculation area behind the holes on the pressure side and induces separation bubbles in between the pressure side holes. This leads to the generation of two pairs of vortices: The kidney-vortex is located on top of a second vortex pair and a trough flow that fills up the deficit of the recirculation. Thus the film cooling air is detached from the pressure side surface. In addition to the mean flow vectors Reynolds stress components are a good means to judge the propagation of the jet. In spite of the complex flow pattern occurring on each single jet, the surveyed loss-increase due to the leading edge blowing can be predicted by the mixing layer model.

scholarly journals Quantitative Visualization of Full-Coverage Discrete-Hole Film Cooling

1997 ◽  
Author(s):  
Thomas F. Fric ◽  
Robert P. Campbell ◽  
Mark G. Rettig
Keyword(s):  
Film Cooling ◽  
Large Scale ◽  
Flow Direction ◽  
Three Dimensional ◽  
Scale Model ◽  
Data Sets ◽  
Injection Angle ◽  
Full Coverage ◽  
Planar Laser ◽  
Quantitative Visualization

Water tunnel experiments were carried out to study full-coverage discrete-hole film cooling for geometries applicable to gas turbine combustor liners. The cooling holes were spaced at a pitch to diameter ratio of 6.5 and had an injection angle of 20° to the cooled surface. The mainstream flow direction was in line with the cooling holes. Blowing ratios from 0.5 to 5.7 were studied, which is a range typical of combustor liners. A unique multiple plane PLIF (planar laser-induced fluorescence) technique was used to measure time-averaged film cooling concentration at various heights above the surface to be cooled. Three-dimensional data sets were generated to quantitatively visualize cooling-jet film coverage, structure, and interaction. Film coverage as close as 0.25 mm (0.010 in.) from the surface was measured, thereby yielding data that approach adiabatic film effectiveness. Two sets of film cooling experiments were conducted. One set used a model with a relatively small array of 2.54 mm (0.100 in.) holes, meant to be a large-scale model of hole sizes encountered in combustor liners. The second set used a large array of 0.51 mm (0.020 in.) nominal diameter laser-drilled holes, manufactured in the same manner as combustor liner cooling holes. The results show that near-wall film coverage is minimum for blowing ratios from 1.7 to 3.3. At blowing ratios less than 1.7 and greater than 3.3, the film coverage was improved. Jet structure and interaction was also observed. In particular, jet separation behavior and coalescence were visualized, and both were generally a function of blowing ratio.

scholarly journals On the effects of membrane viscosity on transient red blood cell dynamics

Soft Matter ◽  
2020 ◽  
Vol 16 (26) ◽  
pp. 6191-6205 ◽  
Author(s):  
Fabio Guglietta ◽  
Marek Behr ◽  
Luca Biferale ◽  
Giacomo Falcucci ◽  
Mauro Sbragaglia
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Blood Cell ◽  
Red Blood Cell ◽  
Blood Circulation ◽  
Hydraulic Properties ◽  
Large Scale ◽  
Mechanical Response ◽  
Cell Dynamics ◽  
Membrane Viscosity

Computational Fluid Dynamics is currently used to design and improve the hydraulic properties of biomedical devices, wherein the large scale blood circulation needs to be simulated by accounting for the mechanical response of RBCs at the mesoscale.

Construction Ventilation Scheme Optimization of Underground Main Powerhouse Based on CFD

2013 ◽  
Vol 368-370 ◽  
pp. 619-623
Author(s):  
Zhen Liu ◽  
Xiao Ling Wang ◽  
Ai Li Zhang
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Flow Field ◽  
Air Flow ◽  
Scheme Optimization ◽  
Pressure Distributions ◽  
Air Volume ◽  
Computational Fluid Dynamics Cfd ◽  
Traditional Construction ◽  
Ventilation Scheme

For the purpose of avoiding the deficiency of the traditional construction ventilation, the ventilation of the underground main powerhouse is simulated by the computational fluid dynamics (CFD) to optimize ventilation parameters. A 3D unsteady RNG k-ε model is performed for construction ventilation in the underground main powerhouse. The air-flow field and CO diffusion in the main powerhouse are simulated and analyzed. The two construction ventilation schemes are modelled for the main powerhouse. The optimized ventilation scheme is obtained by comparing the air volume and pressure distributions of the different ventilation schemes.

scholarly journals Effect of Doppler flow meter position on discharge measurement in surcharged manholes

2017 ◽  
Vol 77 (3) ◽  
pp. 647-654 ◽  
Author(s):  
Haoming Yang ◽  
David Z. Zhu ◽  
Yanchen Liu
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Flow Field ◽  
Flow Regimes ◽  
Flow Meter ◽  
Flow Meters ◽  
Flow Discharge ◽  
Doppler Flow ◽  
Sewer Systems ◽  
Computational Fluid Dynamics Cfd

Abstract Determining the proper installation location of flow meters is important for accurate measurement of discharge in sewer systems. In this study, flow field and flow regimes in two types of manholes under surcharged flow were investigated using a commercial computational fluid dynamics (CFD) code. The error in measuring the flow discharge using a Doppler flow meter (based on the velocity in a Doppler beam) was then estimated. The values of the corrective coefficient were obtained for the Doppler flow meter at different locations under various conditions. Suggestions for selecting installation positions are provided.

The Effect of Different Turbulence Models on the Emitter Discharge by Using Computational Fluid Dynamics

2013 ◽  
Vol 662 ◽  
pp. 586-590
Author(s):  
Gang Lu ◽  
Qing Song Yan ◽  
Bai Ping Lu ◽  
Shuai Xu ◽  
Kang Li
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Flow Field ◽  
Turbulence Models ◽  
Experimental Results ◽  
Turbulent Model ◽  
Simulation Results ◽  
Rsm Model ◽  
Dynamics Method ◽  
Emitter Discharge

Four types of Super Typhoon drip emitter with trapezoidal channel were selected out for the investigation of the flow field of the channel, and the CFD (Computational Fluid Dynamics) method was applied to simulate the micro-field inside the channel. The simulation results showed that the emitter discharge of different turbulent model is 4%-14% bigger than that of the experimental results, the average discharge deviation of κ-ω and RSM model is 5, 4.5 respectively, but the solving efficiency of the κ-ω model is obviously higher than that of the RSM model.

scholarly journals The Midlatitude Continental Convective Clouds Experiment (MC3E) sounding network: operations, processing and analysis

2015 ◽  
Vol 8 (1) ◽  
pp. 421-434 ◽  
Author(s):  
M. P. Jensen ◽  
T. Toto ◽  
D. Troyan ◽  
P. E. Ciesielski ◽  
D. Holdridge ◽  
...  
Keyword(s):  
Large Scale ◽  
Scale Model ◽  
Data Sets ◽  
Central Plains ◽  
Data Set ◽  
Convective Systems ◽  
Convective Clouds ◽  
Quality Checks ◽  
Network Operations ◽  
The Impact

Abstract. The Midlatitude Continental Convective Clouds Experiment (MC3E) took place during the spring of 2011 centered in north-central Oklahoma, USA. The main goal of this field campaign was to capture the dynamical and microphysical characteristics of precipitating convective systems in the US Central Plains. A major component of the campaign was a six-site radiosonde array designed to capture the large-scale variability of the atmospheric state with the intent of deriving model forcing data sets. Over the course of the 46-day MC3E campaign, a total of 1362 radiosondes were launched from the enhanced sonde network. This manuscript provides details on the instrumentation used as part of the sounding array, the data processing activities including quality checks and humidity bias corrections and an analysis of the impacts of bias correction and algorithm assumptions on the determination of convective levels and indices. It is found that corrections for known radiosonde humidity biases and assumptions regarding the characteristics of the surface convective parcel result in significant differences in the derived values of convective levels and indices in many soundings. In addition, the impact of including the humidity corrections and quality controls on the thermodynamic profiles that are used in the derivation of a large-scale model forcing data set are investigated. The results show a significant impact on the derived large-scale vertical velocity field illustrating the importance of addressing these humidity biases.

Sign in / Sign up

Export Citation Format

Share Document