Conjugate Heat Transfer Characteristics of a Highly Thermal-Loaded Film Cooling System in Hot and Multi-Composition Gas Condition

2014 ◽  
Author(s):  
Mingfei Li ◽  
Jing Ren ◽  
Hongde Jiang
Keyword(s):  
Heat Transfer ◽  
Film Cooling ◽  
Radiation Effects ◽  
Conjugate Heat Transfer ◽  
Cooling System ◽  
Radiation Heat Transfer ◽  
Numerical Data ◽  
Gas Composition ◽  
Higher Temperature ◽  
Zero Emission

To reach the goal of Zero-Emission or Near-Zero-Emission, the future advanced power equipment would be using hydrogen or middle/low heat-value syngas as fuel. Radiation would be more important in turbine heat transfer due to the higher temperature and multi-composition gas. The main goal of current study is analyzing the characteristic of conjugate heat transfer considering radiation heat transfer, multi-composition gas, with and without TBC coated. To study the conjugate heat transfer mechanism including conduction/ convection/ radiation in the film cooling flow field considering the effect of the gas composition, both the experimental and the numerical studies are carried out in the present work. By comparing the experimental and the numerical data, it is concluded that the implemented thermal conduction/ convection/ radiation simulation method is valid for the cases studied. The results show that higher percentage of steam in gas composition leads to the higher temperature (lower normalized temperature) on the plate. With the total percentage of steam in hot gas increasing per 7%, the normalized temperature on the plate decrease about 0.02. The heat insulation effect of TBC is more obvious when the radiation effects are strong. TBC makes the temperature distribution more uniform to some extent.

Conjugate Heat Transfer Characteristics of a Highly Thermal-Loaded Film Cooling System in Hot and Multicomposition Gas Condition

2015 ◽  
Vol 138 (2) ◽  
Author(s):  
Mingfei Li ◽  
Hong Yin ◽  
Jing Ren ◽  
Hongde Jiang
Keyword(s):  
Heat Transfer ◽  
Film Cooling ◽  
Radiation Effects ◽  
Conjugate Heat Transfer ◽  
Cooling System ◽  
Radiation Heat Transfer ◽  
Simulation Method ◽  
Numerical Studies ◽  
Insulation Effect ◽  
Higher Temperature

Radiation would be more important in turbine heat transfer due to higher temperature and multicomposition gas conditions in the future. The main goal of the current study is analyzing the characteristics of conjugate heat transfer considering radiation heat transfer, multicomposition gas, either with or without TBC coated. Both experimental and numerical studies were carried out. By comparing the experimental and the numerical results, it was concluded that the implemented thermal conduction/convection/radiation simulation method is valid for the cases studied. The results have shown that higher percentage of steam in the gas composition leads to higher temperature (lower normalized temperature) on the plate. With the percentage of steam in the hot gas increasing per 7%, the normalized temperature on the plate decreases about 0.02. The heat insulation effect of TBC is more obvious when the radiation effects are strong.

Clocking Effects of Inlet Non-Uniformities in a Fully Cooled High-Pressure Vane: A Conjugate Heat Transfer Analysis

2015 ◽  
Author(s):  
Duccio Griffini ◽  
Massimiliano Insinna ◽  
Simone Salvadori ◽  
Francesco Martelli
Keyword(s):  
Heat Transfer ◽  
High Pressure ◽  
Film Cooling ◽  
Conjugate Heat Transfer ◽  
Cooling System ◽  
Hot Spot ◽  
Three Dimensional ◽  
Leading Edge ◽  
Suction Side ◽  
Heat Transfer Analysis

A high-pressure vane equipped with a realistic film-cooling configuration has been studied. The vane is characterized by the presence of multiple rows of fan-shaped holes along pressure and suction side while the leading edge is protected by a showerhead system of cylindrical holes. Steady three-dimensional Reynolds-Averaged Navier-Stokes (RANS) simulations have been performed. A preliminary grid sensitivity analysis with uniform inlet flow has been used to quantify the effect of spatial discretization. Turbulence model has been assessed in comparison with available experimental data. The effects of the relative alignment between combustion chamber and high-pressure vanes are then investigated considering realistic inflow conditions in terms of hot spot and swirl. The inlet profiles used are derived from the EU-funded project TATEF2. Two different clocking positions are considered: the first one where hot spot and swirl core are aligned with passage and the second one where they are aligned with the leading edge. Comparisons between metal temperature distributions obtained from conjugate heat transfer simulations are performed evidencing the role of swirl in determining both the hot streak trajectory within the passage and the coolant redistribution. The leading edge aligned configuration is resulted to be the most problematic in terms of thermal load, leading to increased average and local vane temperature peaks on both suction side and pressure side with respect to the passage aligned case. A strong sensitivity of both injected coolant mass flow and heat removed by heat sink effect has also been highlighted for the showerhead cooling system.

scholarly journals Conjugate Heat Transfer Characteristics in a Highly Thermally Loaded Film Cooling Configuration with TBC in Syngas

Aerospace ◽  
2019 ◽  
Vol 6 (2) ◽  
pp. 16
Author(s):  
Jing Ren ◽  
Xueying Li ◽  
Hongde Jiang
Keyword(s):  
Heat Transfer ◽  
Radiative Heat Transfer ◽  
Film Cooling ◽  
Conjugate Heat Transfer ◽  
Radiative Heat ◽  
Radiation Heat Transfer ◽  
Transfer Model ◽  
Plate Temperature ◽  
Total Percentage ◽  
Barrier Coating

Future power equipment tends to take hydrogen or middle/low heat-value syngas as fuel for low emission. The heat transfer of a film-cooled turbine blade shall be influenced more by radiation. Its characteristic of conjugate heat transfer is studied experimentally and numerically in the paper by considering radiation heat transfer, multicomposition gas, and thermal barrier coating (TBC). The Weighted Sum of Gray Gases Spectral Model and the Discrete Transfer Model are utilized to solve the radiative heat transfer in the multicomposition field, while validated against the experimental data for the studied cases. It is shown that the plate temperature increases significantly when considering the radiation and the temperature gradient of the film-cooled plate becomes less significant. It is also shown that increasing percentage of steam in gas composition results in increased temperature on the film-cooled plate. The normalized temperature of the film-cooled plate decreases about 0.02, as the total percentage of steam in hot gas increases 7%. As for the TBC effect, it can smooth out the temperature distribution and insulate the heat to a greater extent when the radiative heat transfer becomes significant.

Clocking Effects of Inlet Nonuniformities in a Fully Cooled High-Pressure Vane: A Conjugate Heat Transfer Analysis

2015 ◽  
Vol 138 (2) ◽  
Author(s):  
Duccio Griffini ◽  
Massimiliano Insinna ◽  
Simone Salvadori ◽  
Francesco Martelli
Keyword(s):  
Heat Transfer ◽  
High Pressure ◽  
Film Cooling ◽  
Conjugate Heat Transfer ◽  
Cooling System ◽  
Hot Spot ◽  
Three Dimensional ◽  
Leading Edge ◽  
Suction Side ◽  
Heat Transfer Analysis

A high-pressure vane (HPV) equipped with a realistic film-cooling configuration has been studied. The vane is characterized by the presence of multiple rows of fan-shaped holes along pressure and suction side, while the leading edge (LE) is protected by a showerhead system of cylindrical holes. Steady three-dimensional Reynolds-averaged Navier–Stokes simulations have been performed. A preliminary grid sensitivity analysis with uniform inlet flow has been used to quantify the effect of spatial discretization. Turbulence model has been assessed in comparison with available experimental data. The effects of the relative alignment between combustion chamber and HPVs are then investigated, considering realistic inflow conditions in terms of hot spot and swirl. The inlet profiles used are derived from the EU-funded project TATEF2. Two different clocking positions are considered: the first in which hot spot and swirl core are aligned with passage; and the second in which they are aligned with the LE. Comparisons between metal temperature distributions obtained from conjugate heat transfer (CHT) simulations are performed, evidencing the role of swirl in determining both the hot streak trajectory within the passage and the coolant redistribution. The LE aligned configuration is determined to be the most problematic in terms of thermal load, leading to increased average and local vane temperature peaks on both suction side and pressure side with respect to the passage-aligned case. A strong sensitivity to both injected coolant mass flow and heat removed by heat sink effect has also been highlighted for the showerhead cooling system.

Film Cooling System Numerical Design: Adiabatic and Conjugate Analysis

2005 ◽  
Author(s):  
Antonio Andreini ◽  
Carlo Carcasci ◽  
Stefano Gori ◽  
Marco Surace
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Film Cooling ◽  
Conjugate Heat Transfer ◽  
Cooling System ◽  
Numerical Study ◽  
Single Row ◽  
Numerical Design ◽  
Cooling Behavior

Film cooling is certainly the most diffused system to protect metal surface against hot gases, both in turbogas blades and combustors. Although being very diffused, there are still several aspects of its behavior which need a better understanding. Mainly, the performance of multi-row holes configurations are still estimated correcting single-row correlations. Heat transfer coefficient modifications due to the presence of injected coolant are hard to evaluate, and even now few studies in literature take into account this factor. The present work is a detailed numerical study of some effects of film cooling. 3D CFD-RANS simulations have been performed to infer interesting trends of adiabatic superposition effects and conjugate heat transfer performances. In particular, several calculations have been carried out to evaluate single row and multi-row film cooling behavior in terms of heat transfer coefficient, overall and adiabatic effectiveness. Test were conducted with blowing ratios between 0.5 and 5.5, coolant Reynolds from 1000 to 16000.

Effect of the Hot Gas Composition on a Highly Thermally Loaded Film Cooling System

2011 ◽  
Author(s):  
Peng Sun ◽  
Wenping Wang ◽  
Jing Ren ◽  
Hongde Jiang
Keyword(s):  
Heat Transfer ◽  
Temperature Rise ◽  
Radiative Heat Transfer ◽  
Film Cooling ◽  
Radiative Heat ◽  
Fuel Cycle ◽  
Cooling System ◽  
Transfer Model ◽  
Gas Composition ◽  
Hot Gas

To reduce the CO2 emission, three types of the coal-based power generation system are promising: IGCC, the hydrogen-fired turbine cycle and the oxy-fuel cycle. The thermal characteristics of the turbines are expected to be dependent on the different hot and wet gases. For studying the effect of the hot gas composition on the highly thermally loaded cooling system, both the experimental and the numerical studies are carried out in the present work. Five hot gases are focused in the study, which are corresponding to the combustion products of the liquefied petroleum gas, the natural gas, the syngas, the hydrogen and the oxy-fuel gas. A highly thermally loaded film cooling test rig is built up in Tsinghua University. The Discrete Transfer Model (DTM) and the Weighted Sum of Gray Gases (WSGG) spectral model are employed to solve the radiative heat transfer in the multi-composition field. By comparing the experimental and the numerical data, it is resulted that the implemented thermal conduction/convection/radiation method is valid for the studied cases. The results show that the temperature rise on the plate top surface is about 50∼60 K under the condition of the five hot gas compositions due to the radiative heat transfer. The magnitude of the temperature rise is the reverse of the mole fraction of the radiative gases (CO2+H2O) in the hot gas. Furthermore, the local temperature gradient is weakened in the five hot gas compositions cases. It means that the thermodynamics of the film cooling system in the multi-composition hot gas has its own characteristics. It may play a role in the future coal-based turbine technology.

scholarly journals Conjugate Heat Transfer Characteristics in a Highly Thermally Loaded Film Cooling Configuration with TBC in Syngas

2018 ◽  
Author(s):  
Jing Ren ◽  
Xueying Li ◽  
Hongde Jiang
Keyword(s):  
Heat Transfer ◽  
Radiative Heat Transfer ◽  
Film Cooling ◽  
Conjugate Heat Transfer ◽  
Radiative Heat ◽  
Radiation Heat Transfer ◽  
Transfer Model ◽  
Plate Temperature ◽  
Total Percentage ◽  
Heat Value

The future power equipment tends to take hydrogen or middle/low heat-value syngas as fuel for low emission. The heat transfer of film cooled turbine blade shall be influenced more by radiation. Its characteristic of conjugate heat transfer is studied experimentally and numerically in the paper by considering radiation heat transfer, multi-composition gas and TBC. The Weighted Sum of Gray Gases spectral model and Discrete Transfer Model are utilized to solve the radiative heat transfer in the multi-composition field, while validated against the experimental data for the studied cases. It is shown that the plate temperature increases significantly when considering the radiation and the temperature gradient of the film cooled plate becomes larger. It is also shown that increasing percentage of steam in gas composition results in increased temperature on the film-cooled plate. The normalized temperature of the film-cooled plate decreases about 0.02, as the total percentage of steam in hot gas increases per 7%. As for the TBC effect, it can smooth out the the temperature distribution and insulate the heat to a greater extent when the radiative heat transfer becomes significant.

Conjugate Heat Transfer and Film Cooling of a Multi-Stage Cooling Scheme

2008 ◽  
Author(s):  
M. Ghorab ◽  
S. I. Kim ◽  
I. Hassan
Keyword(s):  
Heat Transfer ◽  
Film Cooling ◽  
Gas Turbines ◽  
Conjugate Heat Transfer ◽  
Density Ratio ◽  
Design Parameters ◽  
Cooling Effectiveness ◽  
Film Cooling Effectiveness ◽  
Multi Stage ◽  
Internal Gap

Cooling techniques play a key role in improving efficiency and power output of modern gas turbines. The conjugate technique of film and impingement cooling schemes is considered in this study. The Multi-Stage Cooling Scheme (MSCS) involves coolant passing from inside to outside turbine blade through two stages. The first stage; the coolant passes through first hole to internal gap where the impinging jet cools the external layer of the blade. Finally, the coolant passes through the internal gap to the second hole which has specific designed geometry for external film cooling. The effect of design parameters, such as, offset distance between two-stage holes, gap height, and inclination angle of the first hole, on upstream conjugate heat transfer rate and downstream film cooling effectiveness performance are investigated computationally. An Inconel 617 alloy with variable properties is selected for the solid material. The conjugate heat transfer and film cooling characteristics of MSCS are analyzed across blowing ratios of Br = 1 and 2 for density ratio, 2. This study presents upstream wall temperature distributions due to conjugate heat transfer for different gap design parameters. The maximum film cooling effectiveness with upstream conjugate heat transfer is less than adiabatic film cooling effectiveness by 24–34%. However, the full coverage of cooling effectiveness in spanwise direction can be obtained using internal cooling with conjugate heat transfer, whereas adiabatic film cooling effectiveness has narrow distribution.

Experimental and numerical investigations on a high-density polyethylene (HDPE) blown film cooling with a new design of the counter-flow/radial jet air-ring

2021 ◽  
pp. 875608792110260
Author(s):  
ME Ismail ◽  
MM Awad ◽  
AM Hamed ◽  
MY Abdelaal ◽  
EB Zeidan
Keyword(s):  
Heat Transfer ◽  
Numerical Simulations ◽  
Film Cooling ◽  
Radiation Heat Transfer ◽  
Absolute Error ◽  
Numerical Results ◽  
Upper Lip ◽  
Original Design ◽  
Blown Film ◽  
Set Up

This study experimentally and numerically investigates a typical HDPE blown film production process cooled via a single-lip air-ring. The processing observations are considered for the proposed subsequent modifications on the air-ring design and the location relative to the die to generate a radial jet, directly impinging on the bubble. Measurements are performed to collect the actual operating parameters to set up the numerical simulations. The radiation heat transfer and the polymer phase change are considered in the numerical simulations. The velocity profile at the air-ring upper-lip is measured via a five-hole Pitot tube to compare with the numerical results. The comparison between the measurements and the numerical results showed that the simulations with the STD [Formula: see text] turbulence model are more accurate with a minimum relative absolute error (RAE) of 1.6%. The numerical results indicate that the peak Heat Transfer Coefficient (HTC) at the impingement point for the modified design with radial jet and longer upper-lip is 29.1% higher than the original design at the same conditions. Besides, increasing the air-ring upper-lip height increased the averaged HTC, which is 13.4% higher than the original design.

Combined Experimental and CFD Study of a HP Blade Multi-Pass Cooling System

2009 ◽  
Author(s):  
D. Jackson ◽  
P. Ireland ◽  
B. Cheong
Keyword(s):  
Heat Transfer ◽  
Film Cooling ◽  
Cooling System ◽  
Detailed Comparison ◽  
Bulk Temperature ◽  
Internal Cooling ◽  
3 Dimensional ◽  
Turbine Cooling ◽  
Cooling Hole ◽  
The Difference

Progress in the computing power available for CFD predictions now means that full geometry, 3 dimensional predictions are now routinely used in internal cooling system design. This paper reports recent work at Rolls-Royce which has compared the flow and htc predictions in a modern HP turbine cooling system to experiments. The triple pass cooling system includes film cooling vents and inclined ribs. The high resolution heat transfer experiments show that different cooling performance features are predicted with different levels of fidelity by the CFD. The research also revealed the sensitivity of the prediction to accurate modelling of the film cooling hole discharge coefficients and a detailed comparison of the authors’ computer predictions to data available in the literature is reported. Mixed bulk temperature is frequently used in the determination of heat transfer coefficient from experimental data. The current CFD data is used to compare the mixed bulk temperature to the duct centreline temperature. The latter is measured experimentally and the effect of the difference between mixed bulk and centreline temperature is considered in detail.

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