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Thomas Povey - One of the best experts on this subject based on the ideXlab platform.
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cooling optimization theory part i optimum wall Temperature coolant Exit Temperature and the effect of wall film properties on performance
Journal of Turbomachinery-transactions of The Asme, 2016Co-Authors: Benjamin Kirollos, Thomas PoveyAbstract:Gas turbine cooling system design is constrained by a maximum allowable wall Temperature (dictated by the material and the life requirements of the component), minimum coolant mass flow rate (the requirement to minimize cycle-efficiency cost), and uniform wall Temperature (to reduce thermal stresses). These three design requirements form the basis of an iterative design process. The relationship between the requirements has received little discussion in the literature, despite being of interest from both a theoretical and a practical viewpoint. In this paper, we consider the optimum cooling system for parts with both internal and film cooling. We show analytically that the coolant mass flow rate is minimized when the wall Temperature is uniform and equal to the maximum allowable wall Temperature. Thus, we show that achieving uniform wall Temperature achieves minimum coolant flow rate, and vice versa. The purpose is to clarify the interplay between two design requirements that are often discussed separately in the literature. The penalty (in terms of coolant mass flow) associated with cooling nonisothermal components is quantified. We show that a typical high pressure nozzle guide vane (HPNGV) operating isothermally at the maximum allowable wall Temperature requires two-thirds the coolant of a typical nonisothermal vane. The optimum coolant Exit Temperature is also considered. It is shown analytically that the optimum coolant Exit Temperature depends on the balance between the mean adiabatic film cooling effectiveness, the nondimensional mass flow rate, and the Biot number of the thermal barrier coating (TBC). For the large majority of gas turbine cooling systems (e.g., a typical HPNGV) it is shown that the optimum coolant Exit Temperature is equal to the local wall Temperature at the point of injection. For a small minority of systems (e.g., long effusion cooling systems operating at low mass flow rates), it is shown that the coolant Exit Temperature should be minimized. An approximation relating the wall/film properties, the nondimensional mass flow, and the overall cooling effectiveness is derived. It is used to estimate the effect of Biot number (TBC and metal), heat transfer coefficient (HTC) ratio, and film properties on the performance of a typical HPNGV and effusion cooling system. In Part II, we show that designs which achieve uniform wall Temperature have a particular corresponding internal HTC distribution.
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Cooling Optimization Theory—Part I: Optimum Wall Temperature, Coolant Exit Temperature, and the Effect of Wall/Film Properties on Performance
Journal of Turbomachinery, 2016Co-Authors: Benjamin Kirollos, Thomas PoveyAbstract:Gas turbine cooling system design is constrained by a maximum allowable wall Temperature (dictated by the material and the life requirements of the component), minimum coolant mass flow rate (the requirement to minimize cycle-efficiency cost), and uniform wall Temperature (to reduce thermal stresses). These three design requirements form the basis of an iterative design process. The relationship between the requirements has received little discussion in the literature, despite being of interest from both a theoretical and a practical viewpoint. In this paper, we consider the optimum cooling system for parts with both internal and film cooling. We show analytically that the coolant mass flow rate is minimized when the wall Temperature is uniform and equal to the maximum allowable wall Temperature. Thus, we show that achieving uniform wall Temperature achieves minimum coolant flow rate, and vice versa. The purpose is to clarify the interplay between two design requirements that are often discussed separately in the literature. The penalty (in terms of coolant mass flow) associated with cooling nonisothermal components is quantified. We show that a typical high pressure nozzle guide vane (HPNGV) operating isothermally at the maximum allowable wall Temperature requires two-thirds the coolant of a typical nonisothermal vane. The optimum coolant Exit Temperature is also considered. It is shown analytically that the optimum coolant Exit Temperature depends on the balance between the mean adiabatic film cooling effectiveness, the nondimensional mass flow rate, and the Biot number of the thermal barrier coating (TBC). For the large majority of gas turbine cooling systems (e.g., a typical HPNGV) it is shown that the optimum coolant Exit Temperature is equal to the local wall Temperature at the point of injection. For a small minority of systems (e.g., long effusion cooling systems operating at low mass flow rates), it is shown that the coolant Exit Temperature should be minimized. An approximation relating the wall/film properties, the nondimensional mass flow, and the overall cooling effectiveness is derived. It is used to estimate the effect of Biot number (TBC and metal), heat transfer coefficient (HTC) ratio, and film properties on the performance of a typical HPNGV and effusion cooling system. In Part II, we show that designs which achieve uniform wall Temperature have a particular corresponding internal HTC distribution.
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Cooling Optimisation Theory: Part 1 — Optimum Wall Temperature, Coolant Exit Temperature and the Effect of Wall/Film Properties on Performance
Volume 5A: Heat Transfer, 2015Co-Authors: Benjamin Kirollos, Thomas PoveyAbstract:Gas turbine cooling system design is constrained by a maximum allowable wall Temperature (dictated by the material and the life requirements of the component), minimum coolant mass flow rate (the requirement to minimise cycle-efficiency cost) and uniform wall Temperature (to reduce thermal stresses). These three design requirements form the basis of an iterative design process. The relationship between the requirements has received little discussion in the literature, despite being of interest from both a theoretical and a practical viewpoint. In this paper, we consider the optimum cooling system for parts with both internal and film cooling. We show analytically that the coolant mass flow rate is minimised when the wall Temperature is uniform and equal to the maximum allowable wall Temperature. Thus, we show that achieving uniform wall Temperature achieves minimum coolant flow rate, and vice versa. The purpose is to clarify the interplay between two design requirements that are often discussed separately in the literature. The penalty (in terms of coolant mass flow) associated with cooling non-isothermal components is quantified. We show that a typical high pressure nozzle guide vane (HPNGV) operating isothermally at the maximum allowable wall Temperature requires two-thirds the coolant of a typical non-isothermal vane.The optimum coolant Exit Temperature is also considered. It is shown analytically that the optimum coolant Exit Temperature depends on the balance between the mean adiabatic film cooling effectiveness, the non-dimensional mass flow rate and the Biot number of the thermal barrier coating (TBC). For the large majority of gas turbine cooling systems (e.g., a typical HPNGV) it is shown that the optimum coolant Exit Temperature is equal to the local wall Temperature at the point of injection. For a small minority of systems (e.g., long effusion cooling systems operating at low mass flow rates) it is shown that the coolant Exit Temperature should be minimised.An approximation relating the wall/film properties, the non-dimensional mass flow, and the overall cooling effectiveness is derived. It is used to estimate the effect of Biot number (TBC and metal), HTC ratio and film properties on the performance of a typical HPNGV and effusion cooling system.In the companion paper, we show that designs which achieve uniform wall Temperature have a particular corresponding internal heat transfer coefficient (HTC) distribution.Copyright © 2015 by Rolls-Royce plc
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cooling optimisation theory part 1 optimum wall Temperature coolant Exit Temperature and the effect of wall film properties on performance
ASME Turbo Expo 2015: Turbine Technical Conference and Exposition, 2015Co-Authors: Benjamin Kirollos, Thomas PoveyAbstract:Gas turbine cooling system design is constrained by a maximum allowable wall Temperature (dictated by the material and the life requirements of the component), minimum coolant mass flow rate (the requirement to minimise cycle-efficiency cost) and uniform wall Temperature (to reduce thermal stresses). These three design requirements form the basis of an iterative design process. The relationship between the requirements has received little discussion in the literature, despite being of interest from both a theoretical and a practical viewpoint. In this paper, we consider the optimum cooling system for parts with both internal and film cooling. We show analytically that the coolant mass flow rate is minimised when the wall Temperature is uniform and equal to the maximum allowable wall Temperature. Thus, we show that achieving uniform wall Temperature achieves minimum coolant flow rate, and vice versa. The purpose is to clarify the interplay between two design requirements that are often discussed separately in the literature. The penalty (in terms of coolant mass flow) associated with cooling non-isothermal components is quantified. We show that a typical high pressure nozzle guide vane (HPNGV) operating isothermally at the maximum allowable wall Temperature requires two-thirds the coolant of a typical non-isothermal vane.The optimum coolant Exit Temperature is also considered. It is shown analytically that the optimum coolant Exit Temperature depends on the balance between the mean adiabatic film cooling effectiveness, the non-dimensional mass flow rate and the Biot number of the thermal barrier coating (TBC). For the large majority of gas turbine cooling systems (e.g., a typical HPNGV) it is shown that the optimum coolant Exit Temperature is equal to the local wall Temperature at the point of injection. For a small minority of systems (e.g., long effusion cooling systems operating at low mass flow rates) it is shown that the coolant Exit Temperature should be minimised.An approximation relating the wall/film properties, the non-dimensional mass flow, and the overall cooling effectiveness is derived. It is used to estimate the effect of Biot number (TBC and metal), HTC ratio and film properties on the performance of a typical HPNGV and effusion cooling system.In the companion paper, we show that designs which achieve uniform wall Temperature have a particular corresponding internal heat transfer coefficient (HTC) distribution.Copyright © 2015 by Rolls-Royce plc
Benjamin Kirollos - One of the best experts on this subject based on the ideXlab platform.
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cooling optimization theory part i optimum wall Temperature coolant Exit Temperature and the effect of wall film properties on performance
Journal of Turbomachinery-transactions of The Asme, 2016Co-Authors: Benjamin Kirollos, Thomas PoveyAbstract:Gas turbine cooling system design is constrained by a maximum allowable wall Temperature (dictated by the material and the life requirements of the component), minimum coolant mass flow rate (the requirement to minimize cycle-efficiency cost), and uniform wall Temperature (to reduce thermal stresses). These three design requirements form the basis of an iterative design process. The relationship between the requirements has received little discussion in the literature, despite being of interest from both a theoretical and a practical viewpoint. In this paper, we consider the optimum cooling system for parts with both internal and film cooling. We show analytically that the coolant mass flow rate is minimized when the wall Temperature is uniform and equal to the maximum allowable wall Temperature. Thus, we show that achieving uniform wall Temperature achieves minimum coolant flow rate, and vice versa. The purpose is to clarify the interplay between two design requirements that are often discussed separately in the literature. The penalty (in terms of coolant mass flow) associated with cooling nonisothermal components is quantified. We show that a typical high pressure nozzle guide vane (HPNGV) operating isothermally at the maximum allowable wall Temperature requires two-thirds the coolant of a typical nonisothermal vane. The optimum coolant Exit Temperature is also considered. It is shown analytically that the optimum coolant Exit Temperature depends on the balance between the mean adiabatic film cooling effectiveness, the nondimensional mass flow rate, and the Biot number of the thermal barrier coating (TBC). For the large majority of gas turbine cooling systems (e.g., a typical HPNGV) it is shown that the optimum coolant Exit Temperature is equal to the local wall Temperature at the point of injection. For a small minority of systems (e.g., long effusion cooling systems operating at low mass flow rates), it is shown that the coolant Exit Temperature should be minimized. An approximation relating the wall/film properties, the nondimensional mass flow, and the overall cooling effectiveness is derived. It is used to estimate the effect of Biot number (TBC and metal), heat transfer coefficient (HTC) ratio, and film properties on the performance of a typical HPNGV and effusion cooling system. In Part II, we show that designs which achieve uniform wall Temperature have a particular corresponding internal HTC distribution.
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Cooling Optimization Theory—Part I: Optimum Wall Temperature, Coolant Exit Temperature, and the Effect of Wall/Film Properties on Performance
Journal of Turbomachinery, 2016Co-Authors: Benjamin Kirollos, Thomas PoveyAbstract:Gas turbine cooling system design is constrained by a maximum allowable wall Temperature (dictated by the material and the life requirements of the component), minimum coolant mass flow rate (the requirement to minimize cycle-efficiency cost), and uniform wall Temperature (to reduce thermal stresses). These three design requirements form the basis of an iterative design process. The relationship between the requirements has received little discussion in the literature, despite being of interest from both a theoretical and a practical viewpoint. In this paper, we consider the optimum cooling system for parts with both internal and film cooling. We show analytically that the coolant mass flow rate is minimized when the wall Temperature is uniform and equal to the maximum allowable wall Temperature. Thus, we show that achieving uniform wall Temperature achieves minimum coolant flow rate, and vice versa. The purpose is to clarify the interplay between two design requirements that are often discussed separately in the literature. The penalty (in terms of coolant mass flow) associated with cooling nonisothermal components is quantified. We show that a typical high pressure nozzle guide vane (HPNGV) operating isothermally at the maximum allowable wall Temperature requires two-thirds the coolant of a typical nonisothermal vane. The optimum coolant Exit Temperature is also considered. It is shown analytically that the optimum coolant Exit Temperature depends on the balance between the mean adiabatic film cooling effectiveness, the nondimensional mass flow rate, and the Biot number of the thermal barrier coating (TBC). For the large majority of gas turbine cooling systems (e.g., a typical HPNGV) it is shown that the optimum coolant Exit Temperature is equal to the local wall Temperature at the point of injection. For a small minority of systems (e.g., long effusion cooling systems operating at low mass flow rates), it is shown that the coolant Exit Temperature should be minimized. An approximation relating the wall/film properties, the nondimensional mass flow, and the overall cooling effectiveness is derived. It is used to estimate the effect of Biot number (TBC and metal), heat transfer coefficient (HTC) ratio, and film properties on the performance of a typical HPNGV and effusion cooling system. In Part II, we show that designs which achieve uniform wall Temperature have a particular corresponding internal HTC distribution.
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Cooling Optimisation Theory: Part 1 — Optimum Wall Temperature, Coolant Exit Temperature and the Effect of Wall/Film Properties on Performance
Volume 5A: Heat Transfer, 2015Co-Authors: Benjamin Kirollos, Thomas PoveyAbstract:Gas turbine cooling system design is constrained by a maximum allowable wall Temperature (dictated by the material and the life requirements of the component), minimum coolant mass flow rate (the requirement to minimise cycle-efficiency cost) and uniform wall Temperature (to reduce thermal stresses). These three design requirements form the basis of an iterative design process. The relationship between the requirements has received little discussion in the literature, despite being of interest from both a theoretical and a practical viewpoint. In this paper, we consider the optimum cooling system for parts with both internal and film cooling. We show analytically that the coolant mass flow rate is minimised when the wall Temperature is uniform and equal to the maximum allowable wall Temperature. Thus, we show that achieving uniform wall Temperature achieves minimum coolant flow rate, and vice versa. The purpose is to clarify the interplay between two design requirements that are often discussed separately in the literature. The penalty (in terms of coolant mass flow) associated with cooling non-isothermal components is quantified. We show that a typical high pressure nozzle guide vane (HPNGV) operating isothermally at the maximum allowable wall Temperature requires two-thirds the coolant of a typical non-isothermal vane.The optimum coolant Exit Temperature is also considered. It is shown analytically that the optimum coolant Exit Temperature depends on the balance between the mean adiabatic film cooling effectiveness, the non-dimensional mass flow rate and the Biot number of the thermal barrier coating (TBC). For the large majority of gas turbine cooling systems (e.g., a typical HPNGV) it is shown that the optimum coolant Exit Temperature is equal to the local wall Temperature at the point of injection. For a small minority of systems (e.g., long effusion cooling systems operating at low mass flow rates) it is shown that the coolant Exit Temperature should be minimised.An approximation relating the wall/film properties, the non-dimensional mass flow, and the overall cooling effectiveness is derived. It is used to estimate the effect of Biot number (TBC and metal), HTC ratio and film properties on the performance of a typical HPNGV and effusion cooling system.In the companion paper, we show that designs which achieve uniform wall Temperature have a particular corresponding internal heat transfer coefficient (HTC) distribution.Copyright © 2015 by Rolls-Royce plc
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cooling optimisation theory part 1 optimum wall Temperature coolant Exit Temperature and the effect of wall film properties on performance
ASME Turbo Expo 2015: Turbine Technical Conference and Exposition, 2015Co-Authors: Benjamin Kirollos, Thomas PoveyAbstract:Gas turbine cooling system design is constrained by a maximum allowable wall Temperature (dictated by the material and the life requirements of the component), minimum coolant mass flow rate (the requirement to minimise cycle-efficiency cost) and uniform wall Temperature (to reduce thermal stresses). These three design requirements form the basis of an iterative design process. The relationship between the requirements has received little discussion in the literature, despite being of interest from both a theoretical and a practical viewpoint. In this paper, we consider the optimum cooling system for parts with both internal and film cooling. We show analytically that the coolant mass flow rate is minimised when the wall Temperature is uniform and equal to the maximum allowable wall Temperature. Thus, we show that achieving uniform wall Temperature achieves minimum coolant flow rate, and vice versa. The purpose is to clarify the interplay between two design requirements that are often discussed separately in the literature. The penalty (in terms of coolant mass flow) associated with cooling non-isothermal components is quantified. We show that a typical high pressure nozzle guide vane (HPNGV) operating isothermally at the maximum allowable wall Temperature requires two-thirds the coolant of a typical non-isothermal vane.The optimum coolant Exit Temperature is also considered. It is shown analytically that the optimum coolant Exit Temperature depends on the balance between the mean adiabatic film cooling effectiveness, the non-dimensional mass flow rate and the Biot number of the thermal barrier coating (TBC). For the large majority of gas turbine cooling systems (e.g., a typical HPNGV) it is shown that the optimum coolant Exit Temperature is equal to the local wall Temperature at the point of injection. For a small minority of systems (e.g., long effusion cooling systems operating at low mass flow rates) it is shown that the coolant Exit Temperature should be minimised.An approximation relating the wall/film properties, the non-dimensional mass flow, and the overall cooling effectiveness is derived. It is used to estimate the effect of Biot number (TBC and metal), HTC ratio and film properties on the performance of a typical HPNGV and effusion cooling system.In the companion paper, we show that designs which achieve uniform wall Temperature have a particular corresponding internal heat transfer coefficient (HTC) distribution.Copyright © 2015 by Rolls-Royce plc
Takeshi Takeda - One of the best experts on this subject based on the ideXlab platform.
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rosa lstf test and relap5 code analyses on pwr 1 vessel upper head small break loca with accident management measure based on core Exit Temperature
Nuclear Engineering and Technology, 2018Co-Authors: Takeshi TakedaAbstract:Abstract An experiment was performed using the large-scale test facility (LSTF), which simulated a 1% vessel upper head small-break loss-of-coolant accident with an accident management (AM) measure under an assumption of total-failure of high-pressure injection (HPI) system in a pressurized water reactor (PWR). In the LSTF test, liquid level in the upper head affected break flow rate. Coolant was manually injected from the HPI system into cold legs as the AM measure when the maximum core Exit Temperature reached 623 K. The cladding surface Temperature largely increased due to late and slow response of the core Exit thermocouples. The AM measure was confirmed to be effective for the core cooling. The RELAP5/MOD3.3 code indicated insufficient prediction of primary coolant distribution. The author conducted uncertainty analysis for the LSTF test employing created phenomena identification and ranking table for each component. The author clarified that peak cladding Temperature was largely dependent on the combination of multiple uncertain parameters within the defined uncertain ranges.
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rosa lstf test and relap5 code analyses on pwr hot leg small break loca with accident management measure based on core Exit Temperature and pkl counterpart test
Annals of Nuclear Energy, 2018Co-Authors: Takeshi TakedaAbstract:Abstract An experiment was performed for the OECD/NEA ROSA-2 Project using the large scale test facility (LSTF), which simulated a hot leg small-break loss-of-coolant accident with steam generator (SG) secondary-side depressurization as an accident management measure based on core Exit Temperature in a pressurized water reactor (PWR). This experiment was conducted under two conditions of high-pressure to meet the PWR pressure condition and of low-pressure to meet the Primӓrkreislӓufe Versuchsanlage (PKL) condition. Core uncovery took place by core boil-off with no reflux coolant from the SGs in the LSTF test. The increase rate of the cladding surface Temperatures from top to center of the core relative to the core Exit Temperature increased according to the linear heat rate in the LSTF test. Some discrepancies appeared between the LSTF low-pressure phase and PKL test results for the core Exit Temperature increase due to differences in low-Temperature structures around the core Exit. The RELAP5/MOD3.3 code indicated a remaining problem in the prediction of the core Exit Temperature due to pseudo coolant mixing. Results of uncertainty analysis for the LSTF low-pressure phase test clarified influences of the combination of the multiple uncertain parameters on peak cladding Temperature within the defined uncertain ranges.
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ROSA/LSTF test and RELAP5 code analyses on PWR hot leg small-break LOCA with accident management measure based on core Exit Temperature and PKL counterpart test
Annals of Nuclear Energy, 2018Co-Authors: Takeshi TakedaAbstract:Abstract An experiment was performed for the OECD/NEA ROSA-2 Project using the large scale test facility (LSTF), which simulated a hot leg small-break loss-of-coolant accident with steam generator (SG) secondary-side depressurization as an accident management measure based on core Exit Temperature in a pressurized water reactor (PWR). This experiment was conducted under two conditions of high-pressure to meet the PWR pressure condition and of low-pressure to meet the Primӓrkreislӓufe Versuchsanlage (PKL) condition. Core uncovery took place by core boil-off with no reflux coolant from the SGs in the LSTF test. The increase rate of the cladding surface Temperatures from top to center of the core relative to the core Exit Temperature increased according to the linear heat rate in the LSTF test. Some discrepancies appeared between the LSTF low-pressure phase and PKL test results for the core Exit Temperature increase due to differences in low-Temperature structures around the core Exit. The RELAP5/MOD3.3 code indicated a remaining problem in the prediction of the core Exit Temperature due to pseudo coolant mixing. Results of uncertainty analysis for the LSTF low-pressure phase test clarified influences of the combination of the multiple uncertain parameters on peak cladding Temperature within the defined uncertain ranges.
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ROSA/LSTF test and RELAP5 code analyses on PWR 1% vessel upper head small-break LOCA with accident management measure based on core Exit Temperature
Nuclear Engineering and Technology, 2018Co-Authors: Takeshi TakedaAbstract:Abstract An experiment was performed using the large-scale test facility (LSTF), which simulated a 1% vessel upper head small-break loss-of-coolant accident with an accident management (AM) measure under an assumption of total-failure of high-pressure injection (HPI) system in a pressurized water reactor (PWR). In the LSTF test, liquid level in the upper head affected break flow rate. Coolant was manually injected from the HPI system into cold legs as the AM measure when the maximum core Exit Temperature reached 623 K. The cladding surface Temperature largely increased due to late and slow response of the core Exit thermocouples. The AM measure was confirmed to be effective for the core cooling. The RELAP5/MOD3.3 code indicated insufficient prediction of primary coolant distribution. The author conducted uncertainty analysis for the LSTF test employing created phenomena identification and ranking table for each component. The author clarified that peak cladding Temperature was largely dependent on the combination of multiple uncertain parameters within the defined uncertain ranges.
William Allan - One of the best experts on this subject based on the ideXlab platform.
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Effects of Combustion Chamber Geometry Deviations Upon Exit Temperature Profiles for Populations With Varied Service Limitations
Journal of Engineering for Gas Turbines and Power, 2011Co-Authors: Clayton Kotzer, Marc Laviolette, William Allan, Asad AsgharAbstract:The purpose of this continuing research was to investigate the effects of combustion chamber geometry on Exit Temperature fields using a validated ambient pressure test rig. Rig test conditions were set to simulate an engine operating condition of 463 km/h (250 kn) at 7620 m (25,000 ft) by matching Mach number, equivalence ratio, and Sauter mean diameter of the fuel spray. Using a thermocouple rake, high resolution Temperature measurements were obtained in the combustion chamber Exit plane. Following the previously published procedures, a three-dimensional laser scanning system was used to quantify geometric deviations from two populations of combustion chambers. These populations differed in that one had a significantly higher allowable engine operating Temperature for continuous cruise condition. Geometric deviations of both populations were compared with the reference model. The relationship between combustion chamber Exit Temperature profile and geometric deviation of each population was then compared. The main conclusion of this research was that the Temperature profile degradation of both populations due to geometric deviations followed similar trends. These results highlighted that the difference in operating limitations of these populations did not significantly affect component performance.
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Effects of Combustion Chamber Geometry Deviations Upon Exit Temperature Profiles for Populations With Varied Service Limitations
Volume 2: Combustion Fuels and Emissions Parts A and B, 2010Co-Authors: Clayton Kotzer, Marc Laviolette, William Allan, Asad AsgharAbstract:The purpose of this continuing research was to investigate the effects of combustion chamber geometry on Exit Temperature fields using a validated ambient pressure test rig. Rig test conditions were set to simulate an engine operating condition of 463 km/h (250 knots) at 7 620 m (25,000 ft) by matching Mach number, equivalence ratio and Sauter mean diameter of the fuel spray. Using a thermocouple rake, high resolution Temperature measurements were obtained in the combustion chamber Exit plane. Following the previously published procedures, a three-dimensional laser scanning system was used to quantify geometric deviations from two populations of combustion chambers. These populations differed in that one had a significantly higher allowable engine operating Temperature for continuous cruise condition. Geometric deviations of both populations were compared to the reference model. The relationship between combustion chamber Exit Temperature profile and geometric deviation of each population was then compared. The main conclusion of this research was that the Temperature profile degradation of both populations due to geometric deviations followed similar trends. These results highlighted that the difference in operating limitations of these populations did not significantly affect component performance.© 2010 ASME
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Effects of Fuel Nozzle Condition on Gas Turbine Combustion Chamber Exit Temperature Distributions
Volume 2: Combustion Fuels and Emissions Parts A and B, 2010Co-Authors: Kristen Bishop, William AllanAbstract:The effects of fuel nozzle condition on the Temperature distributions experienced by the nozzle guide vanes have been investigated using an optical patternator. Average spray cone angle, symmetry, and fuel streaks were quantified. An ambient pressure and Temperature combustion chamber test rig was used to capture Exit Temperature distributions and to determine the pattern factor. The rig tests matched representative engine operating conditions by matching Mach number, equivalence ratio, and fuel droplet size. It was observed that very small deviations (± 10° in spray cone angle) from a nominal distribution in the fuel nozzle spray pattern correlated to increases in pattern factor, apparently due to a degradation of mixing processes, which created larger regions of very high Temperature core flow and smaller regions of cooler Temperatures within the combustion chamber Exit plane. The spray cone angle had the most measureable influence while the effects of spray roundness and streak intensity had slightly less influence. Comparisons were made with published studies conducted on the combustion chamber geometry, and recommendations were made for fuel nozzle inspections.Copyright © 2010 by ASME
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Effects of Combustion Chamber Geometry Upon Exit Temperature Profiles
Volume 2: Combustion Fuels and Emissions, 2009Co-Authors: Clayton Kotzer, Marc Laviolette, William AllanAbstract:The purpose of this research was to investigate the effects of combustion chamber geometry on Exit Temperature fields using an ambient pressure test rig. The apparatus contained a 120° sector of a combustion section of a Rolls Royce (previously Allison) T56-A-15 gas turbine engine. A thermocouple rake acquired high-resolution Temperature measurements in the combustion chamber Exit plane. Rig test conditions were set to simulate an engine operating condition of 463 km/h (250 knots) at 7620 m (25000ft) by matching the Mach number, the equivalence ratio and the Sauter mean diameter of the fuel spray. To quantify the geometric deviations of the combustion chamber specimens, which varied in service conditions, a three-dimensional laser scanning system was used. Combustion chamber geometric deviations were extracted through comparison of the scanned data to a reference model using the selected software. The relationship between combustion chamber Exit Temperature profile and geometric deviation was then compared. The main conclusion of this research was that small deviations from nominal dimensions in the dilution zone of the combustion chamber correlated to an increase in pattern factor. A decrease in the mixing of the products of combustion and dilution air was observed as damage in the dilution zone increased. This reduction in mixing created a more compact, higher Temperature core flow. The results obtained from this research were compared to past studies.
Marc Laviolette - One of the best experts on this subject based on the ideXlab platform.
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effects of inlet air distortion on gas turbine combustion chamber Exit Temperature profiles
ASME Turbo Expo 2015: Turbine Technical Conference and Exposition, 2015Co-Authors: O Maqsood, Marc Laviolette, R WoodasonAbstract:Localized damage to turbine inlet nozzles is typically caused by non-uniform Temperature distributions at the combustion chamber Exit. This damage results in decreased turbine performance and can lead to expensive repair or replacement. A test rig was designed and constructed for the Rolls-Royce Allison 250-C20B dual-entry combustion chamber to investigate the effects of inlet air distortion on the combustion chamber’s Exit Temperature fields. The rig includes a purposely built water cooled thermocouple rake to sweep the Exit plane of the combustion chamber. Test rig operating conditions simulated normal engine cruise conditions by matching the quasi-non-dimensional Mach number, equivalence ratio and Sauter mean diameter. The combustion chamber was tested with an even distribution of inlet air and a 4% difference in airflow at either combustion chamber inlet.An even distribution of inlet air to the combustion chamber did not produce a uniform Temperature profile and varying the inlet distribution of air exacerbated the profile’s non-uniformity. The design of the combustion chamber promoted the formation of an oval-shaped toroidal vortex inside the combustion liner, causing localized hot and cool sections separated by 90° that were apparent in the exhaust. Uneven inlet air distributions skewed the oval vortex, increasing the Temperature of the hot section nearest the side with the most airflow and decreasing the Temperature of the hot section on the opposite side.Copyright © 2015 by ASME
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Effects of Combustion Chamber Geometry Deviations Upon Exit Temperature Profiles for Populations With Varied Service Limitations
Journal of Engineering for Gas Turbines and Power, 2011Co-Authors: Clayton Kotzer, Marc Laviolette, William Allan, Asad AsgharAbstract:The purpose of this continuing research was to investigate the effects of combustion chamber geometry on Exit Temperature fields using a validated ambient pressure test rig. Rig test conditions were set to simulate an engine operating condition of 463 km/h (250 kn) at 7620 m (25,000 ft) by matching Mach number, equivalence ratio, and Sauter mean diameter of the fuel spray. Using a thermocouple rake, high resolution Temperature measurements were obtained in the combustion chamber Exit plane. Following the previously published procedures, a three-dimensional laser scanning system was used to quantify geometric deviations from two populations of combustion chambers. These populations differed in that one had a significantly higher allowable engine operating Temperature for continuous cruise condition. Geometric deviations of both populations were compared with the reference model. The relationship between combustion chamber Exit Temperature profile and geometric deviation of each population was then compared. The main conclusion of this research was that the Temperature profile degradation of both populations due to geometric deviations followed similar trends. These results highlighted that the difference in operating limitations of these populations did not significantly affect component performance.
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Effects of Combustion Chamber Geometry Deviations Upon Exit Temperature Profiles for Populations With Varied Service Limitations
Volume 2: Combustion Fuels and Emissions Parts A and B, 2010Co-Authors: Clayton Kotzer, Marc Laviolette, William Allan, Asad AsgharAbstract:The purpose of this continuing research was to investigate the effects of combustion chamber geometry on Exit Temperature fields using a validated ambient pressure test rig. Rig test conditions were set to simulate an engine operating condition of 463 km/h (250 knots) at 7 620 m (25,000 ft) by matching Mach number, equivalence ratio and Sauter mean diameter of the fuel spray. Using a thermocouple rake, high resolution Temperature measurements were obtained in the combustion chamber Exit plane. Following the previously published procedures, a three-dimensional laser scanning system was used to quantify geometric deviations from two populations of combustion chambers. These populations differed in that one had a significantly higher allowable engine operating Temperature for continuous cruise condition. Geometric deviations of both populations were compared to the reference model. The relationship between combustion chamber Exit Temperature profile and geometric deviation of each population was then compared. The main conclusion of this research was that the Temperature profile degradation of both populations due to geometric deviations followed similar trends. These results highlighted that the difference in operating limitations of these populations did not significantly affect component performance.© 2010 ASME
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Effects of Combustion Chamber Geometry Upon Exit Temperature Profiles
Volume 2: Combustion Fuels and Emissions, 2009Co-Authors: Clayton Kotzer, Marc Laviolette, William AllanAbstract:The purpose of this research was to investigate the effects of combustion chamber geometry on Exit Temperature fields using an ambient pressure test rig. The apparatus contained a 120° sector of a combustion section of a Rolls Royce (previously Allison) T56-A-15 gas turbine engine. A thermocouple rake acquired high-resolution Temperature measurements in the combustion chamber Exit plane. Rig test conditions were set to simulate an engine operating condition of 463 km/h (250 knots) at 7620 m (25000ft) by matching the Mach number, the equivalence ratio and the Sauter mean diameter of the fuel spray. To quantify the geometric deviations of the combustion chamber specimens, which varied in service conditions, a three-dimensional laser scanning system was used. Combustion chamber geometric deviations were extracted through comparison of the scanned data to a reference model using the selected software. The relationship between combustion chamber Exit Temperature profile and geometric deviation was then compared. The main conclusion of this research was that small deviations from nominal dimensions in the dilution zone of the combustion chamber correlated to an increase in pattern factor. A decrease in the mixing of the products of combustion and dilution air was observed as damage in the dilution zone increased. This reduction in mixing created a more compact, higher Temperature core flow. The results obtained from this research were compared to past studies.