Experimental investigations of a double-decker jet impingement/film structure's cooling effectiveness

2008 ◽  
Vol 37 (4) ◽  
pp. 232-239
Author(s):  
Zhenxiong Liu ◽  
Junkui Mao ◽  
Wen Guo ◽  
Hefu Jiang
Keyword(s):  
Jet Impingement ◽  
Experimental Investigations ◽  
Cooling Effectiveness ◽  
Double Decker

Experimental Studies on Cooling Effectiveness of the Double-Decker Air Jet Impingement With Film Outflow

2007 ◽  
Author(s):  
Junkui Mao ◽  
Wen Guo ◽  
Zhenxiong Liu ◽  
Jun Zeng
Keyword(s):  
Infrared Radiation ◽  
Experimental Studies ◽  
Jet Impingement ◽  
Experimental Results ◽  
Thermal Camera ◽  
Local Cooling ◽  
Cooling Effectiveness ◽  
Air Jet ◽  
Double Decker ◽  
Wide Range

Experiments were carried out to investigate the cooling effectiveness of a lamellar double-decker impingement/effusion structure. Infrared radiation (I.R.) thermal camera was used to measure the temperature on the outside surface of the lamellar double-decker. Experimental results were obtained for a wide range of governing parameters (blowing rate M (0.0017∼0.0066), the ratio of the jet impingement distance to the diameter of film hole H/D (0.5∼1.25), the ratio of the distance between the jet hole and film hole to the diameter of the film hole P/D (0, 3, 4), and the material of double-decker (Steel and Copper)). It was observed that the local cooling effectiveness η varies with all these parameters in a complicated way. All the results show that higher cooling effectiveness η is achieved in larger blowing rate cases. A certain range of H/D and P/D can be designed to result in the maximum cooling effectiveness η. And η is less sensitive to the material type compared with those parameters such as H/D, M and P/D.

Experimental and numerical investigations of overall cooling effectiveness on a vane endwall with jet impingement and film cooling

2019 ◽  
Vol 148 ◽  
pp. 1148-1163 ◽  
Author(s):  
Xing Yang ◽  
Zhansheng Liu ◽  
Qiang Zhao ◽  
Zhao Liu ◽  
Zhenping Feng ◽  
...  
Keyword(s):  
Film Cooling ◽  
Jet Impingement ◽  
Cooling Effectiveness ◽  
Numerical Investigations

Gas Carry-Under in GLCC for Separated and Recombined Outlet Configurations

2018 ◽  
Author(s):  
Srinivas Swaroop Kolla ◽  
Ram S. Mohan ◽  
Ovadia Shoham
Keyword(s):  
Volume Fraction ◽  
Swirling Flow ◽  
Control Strategies ◽  
Flow Behavior ◽  
Jet Impingement ◽  
Test Facility ◽  
Experimental Investigations ◽  
Level Control ◽  
Complex Flow ◽  
Control Configuration

Gas Carry-Under (GCU) is one of the undesirable phenomena that exists in the GLCC©1 even within the Operational Envelope (OPEN) for liquid carry-over. Few studies that are available on GLCC© GCU have been carried out when the GLCC© is operated in a metering loop configuration characterized by recombined outlets. In such configurations the gas and the liquid outlets of the GLCC are recombined downstream which acts as passive level control. However, studies have shown that the GLCC© OPEN increases significantly when active control strategies are employed. There has not been a systematic study aimed at analyzing the effect of control on the GCU in the GLCC. This study compares the previously published GLCC GCU swirling flow mechanism under recombination outlet configuration with data taken under the separated outlet configuration (control configuration). Experimental investigations for GCU are conducted in a state-of-the-art test facility for air-water and air-oil flow incorporating pressure and level control configurations. The experiments are carried out using a 3″ diameter GLCC© equipped with 3 sequential trap sections to measure simultaneously the Gas Volume Fraction (GVF) and gas evolution in the lower part of the GLCC. Also, gas trap sections are installed in the liquid leg of the GLCC© to measure simultaneously the overall GCU. The liquid level was controlled at 6″ below the GLCC© inlet for all experiments using various control strategies. Tangential wall jet impingement is the cause for entrainment of gas, thereby leading to GCU. 3 different flow mechanisms have been identified in the lower part of the GLCC and have significant effect on the GCU. Viscosity and surface tension are observed to affect the GCU. The extensive acquired data shed light on the complex flow behavior in the lower part of the GLCC© and its effect on the GCU of the GLCC©.

Measurement of Detailed Heat Transfer Coefficient and Film Cooling Effectiveness Distributions Using PSP and TSP

2009 ◽  
Author(s):  
Rebekah A. Russin ◽  
Daniel Alfred ◽  
Lesley M. Wright
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Film Cooling ◽  
Optical Filters ◽  
Experimental Investigations ◽  
Transient Temperature ◽  
Cooling Effectiveness ◽  
Film Cooling Effectiveness ◽  
Wide Range

This paper presents the development of a novel experimental technique utilizing both temperature and pressure sensitive paints (TSP and PSP). Through the combination of these paints, both detailed heat transfer coefficient and film cooling effectiveness distributions can be obtained from two short experiments. Using a mass transfer analogy, PSP has proven to be a powerful technique for measurement of film cooling effectiveness. This benefit is exploited to obtain detailed film cooling effectiveness distributions from a steady state flow experiment. This measured film cooling effectiveness is combined with transient temperature distributions obtained from a transient TSP experiment to produce detailed heat transfer coefficient distributions. Optical filters are used to differentiate the light emission from the florescent molecules comprising the PSP and TSP. Although two separate tests are needed to obtain the heat transfer coefficient distributions, the two tests can be performed in succession to minimize setup time and variability. The detailed film effectiveness and heat transfer enhancement ratios have been obtained for a generic, inclined angle (θ = 35°) hole geometry on a flat plate. Distinctive flow features over a wide range of blowing ratios have been captured with the proposed technique. In addition, the measured results have compared favorably to previous studies (both qualitatively and quantitatively), thus substantiating the use of the combined PSP / TSP technique for experimental investigations of three temperature mixing problems.

Experimental Investigations on Aero-Thermal Interaction of Film Cooling Airs Ejected From Multiple Holes: Shallow Hole Angle

2012 ◽  
Author(s):  
Kamil Abdullah ◽  
Ken-ichi Funazaki ◽  
Hisato Onodera ◽  
Takeomi Ideta
Keyword(s):  
Film Cooling ◽  
Experimental Investigations ◽  
Contour Plot ◽  
Test Model ◽  
Cooling Effectiveness ◽  
Film Cooling Effectiveness ◽  
Test Models ◽  
Thermal Investigations ◽  
Baseline Test ◽  
Pitch Distance

This paper presents thermal and aerodynamics investigations of multiple cooling holes with shallow hole angle. Three test models have been considered namely TMA, TMB and TMG. TMB is acting as the baseline test model having 35° hole angle cooling holes. The other two test models; TMA and TMG, have a shallow hole angle of 20° with different lateral pitch distance of 6D and 3D respectively. Total of twenty conventional cylindrical cooling holes have been arranged to form a five times four matrix. All three test models have been considered in the thermal investigations with only the shallow hole angle test models have been considered for the aerodynamics investigation. The film cooling effectiveness has been measured by means of infrared thermography while 3D-LDV has been utilized for the flowfield measurements. The measurements were carried out at single Reynolds number base on the hole diameter of 6200 at three different blowing ratios of 0.5, 1.0 and 2.0. All three blowing ratios have been considered in the thermal investigations with only the latter two blowing ratios were considered in the aerodynamics investigation. The results are presented in the form of contour plot of various variables including film cooling effectiveness, normalized u, v, and w velocities, normalized root mean square of u velocity and Reynolds stress tensors. Distribution of laterally average film cooling effectiveness along the x-axis are also presented, showing that the 20° hole angle cooling holes provide a very promising results particularly at high blowing ratio. The velocities contours clearly capture the flow structure of the film cooling jets, along with the effects of blowing ratios and lateral pitch on the flowfield.

Jet Impingement Cooling System on the Pressure Side of Turbine Blade

2014 ◽  
Vol 695 ◽  
pp. 503-507
Author(s):  
Mohamad Nor Musa ◽  
Mohamed Izhar Mohamed Khalid
Keyword(s):  
Reynolds Number ◽  
Nusselt Number ◽  
Turbine Blade ◽  
Nozzle Exit ◽  
Cooling System ◽  
Jet Impingement ◽  
Pressure Side ◽  
Cooling Effectiveness ◽  
Impingement Cooling ◽  
Surface Distance

This study is to investigate the effectiveness of jet impingement cooling system on the turbine blade pressure side. The objective of this study is to determine the mass blowing rate referred to Reynolds number and the nozzle exit to surface distance which will produce the highest cooling effectiveness which will be shown as Nusselt number. A model of CF6-50 blade is made from mild steel and an experiment to study the jet impingement cooling effectiveness on the pressure side of turbine blade is conducted. The parameters that are included in the experiment are the Reynolds number, Re = 646, 1322, 1970 and 2637; and nozzle exit to surface distance, s/d = 4.0 cm, 8.0 cm and 12.0 cm. The results obtained are calculated and graphs for each experiment are made. The result shows that the jet impingement cooling effectiveness are the highest at where the nozzle is pointed and the cooling effectiveness decreases as it travels further away on the blade. The theory of jet impingement cooling is presented and the several factors that affect jet impingement cooling are also discussed.

Effects of Jetting Orifice Geometry Parameters and Channel Reynolds Number on Bended Channel Cooling for a Novel Internal Cooling Structure

2019 ◽  
Author(s):  
Wei He ◽  
Qinghua Deng ◽  
Juan He ◽  
Tieyu Gao ◽  
Zhenping Feng
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Film Cooling ◽  
Leading Edge ◽  
Jet Impingement ◽  
Suction Side ◽  
Outer Wall ◽  
Internal Cooling ◽  
Cooling Effectiveness ◽  
Blade Leading Edge

Abstract A novel internal cooling structure has been raised recently to enhance internal cooling effectiveness and reduce coolant requirement without using film cooling. This study mainly focuses on verifying the actual cooling performance of the structure and investigating the heat transfer mechanism of the leading edge part of the structure, named bended channel cooling. The cooling performances of the first stage of GE-E3 turbine with three different blade leading edge cooling structures (impingement cooling, swirl cooling and bended channel cooling) were simulated using the conjugate heat transfer method. Furthermore, the effects of jetting orifice geometry and channel Reynolds number were studied with simplified models to illustrate the flow and heat transfer characteristics of the bended channel cooling. The results show that the novel internal cooling structure has obvious advantages on the blade leading edge and suction side under operating condition. The vortex core structure in the bended channel depends on orifice width, but not channel Reynolds number. With the ratio of orifice width to outer wall thickness smaller than a critical value of 0.5, the coolant flows along the external surface of the channel in the pattern of “inner film cooling”, which is pushed by centrifugal force and minimizes the mixing with spent cooling air. Namely, the greatly organized coolant flow generates higher cooling effectiveness and lower coolant demand. Both the Nusselt number on the channel surfaces and total pressure loss increase significantly when the orifice width falls or channel Reynolds increases, but the wall jet impingement distance appears to be less influential.

Effects of Cooling Configurations on the Aerothermal Performance of a Turbine Endwall With Jet Impingement and Film Cooling

2021 ◽  
Vol 143 (6) ◽  
Author(s):  
Hongyan Bu ◽  
Zhendong Guo ◽  
Liming Song ◽  
Jun Li
Keyword(s):  
Film Cooling ◽  
Design Space ◽  
Cooling System ◽  
Uniform Design ◽  
Jet Impingement ◽  
Hole Diameter ◽  
Performance Criteria ◽  
Channel Height ◽  
Inlet Temperature ◽  
Cooling Effectiveness

Abstract With the increase of turbine inlet temperature and the application of premixed combustion, turbine components, particularly the turbine endwall, work in a harsh environment and must be effectively cooled to ensure the component durability. Recently, new cooling schemes that employ both external film cooling and internal jet impingement cooling have drawn much attention due to their extraordinary performance. In this study, a numerical model of turbine endwall with jet impingement and film cooling was established and validated against the experiment. To investigate the effects of geometric parameters related to this cooling scheme, four parameters including impingement hole-to-hole pitch Pi, impingement hole diameter Di, impingement channel height H, and film hole diameter Df were selected to adjust within a reasonable range. The uniform design method was used to collect a database that represented the design space formed by the four parameters. Performance criteria including area-averaged overall cooling effectiveness, standard deviation of overall cooling effectiveness, and total pressure drop coefficient of the cooling system were evaluated through computational fluid dynamics (CFD) calculations. To explore and exploit the design space, a Kriging model was built from the database. Analysis of variance (ANOVA) was conducted afterward to investigate the main effect of each parameter and the correlation between parameters. Finally, based upon the knowledge obtained from ANOVA, typical designs were selected which yielded either best or poorest performances. Through detailed analysis of flow and heat transfer mechanisms of these designs, the influence of each parameter was illustrated clearly and suggestions for the design of similar cooling schemes were drawn.

Effects of Cooling Configurations on the Aerothermal Performance of a Turbine Endwall With Jet Impingement and Film Cooling

2020 ◽  
Author(s):  
Hongyan Bu ◽  
Zhendong Guo ◽  
Liming Song ◽  
Jun Li
Keyword(s):  
Surrogate Model ◽  
Film Cooling ◽  
Design Space ◽  
Cooling System ◽  
Design Method ◽  
Uniform Design ◽  
Jet Impingement ◽  
Channel Height ◽  
Inlet Temperature ◽  
Cooling Effectiveness

Abstract With the rapid increase of turbine inlet temperature and the application of premixed combustion, turbine components, particularly the turbine endwall, works in extremely harsh environment and must be effectively cooled to ensure the component durability. Recently, new cooling schemes that employ both external film cooling and internal jet impingement cooling have drawn much attention due to their extraordinary performance. In this study, a numerical model of turbine endwall with jet impingement and film cooling was established and validated against the experimental results. To investigate the effects of geometric parameters related with this cooling scheme, four parameters including impingement hole-to-hole pitch Pi, impingement hole diameter Di, impingement channel height H, film hole diamete Df, were selected to adjust within a reasonable range. The uniform design method was used to collect a database that represented the design space formed by the four parameters. Performance criterions including area-averaged overall cooling effectiveness, standard deviation of overall cooling effectiveness, total pressure drop coefficient of the cooling system were evaluated through CFD calculations. To explore and exploit the design space as much as possible, a Kriging surrogate model was built from the database. Analysis of variance (ANOVA) was conducted based upon the surrogate model to investigate the main effect of each parameter and the correlation between parameters. Finally, based upon the knowledge obtained from ANOVA, typical designs were selected from the database which yielded either best or poorest performances. Through detailed analysis of flow and heat transfer mechanisms of these typical designs, the influence of each parameter was illustrated clearly and suggestions for the design of similar cooling schemes were drawn.

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