The Experts below are selected from a list of 13944 Experts worldwide ranked by ideXlab platform
Michael E. Crawford - One of the best experts on this subject based on the ideXlab platform.
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Effect of Endwall Contouring on a Transonic Turbine Blade Passage: Heat Transfer Performance
Journal of Turbomachinery, 2016Co-Authors: Kapil Panchal, Santosh Abraham, Arnab Roy, Srinath V. Ekkad, Andrew S. Lohaus, Michael E. CrawfordAbstract:Effect of turbine endwall contouring on its aerodynamic performance has been widely studied, but only a few studies are available in the open literature investigating its effect on heat transfer performance; especially at transonic exit Mach number conditions. In this paper, we report a study of effect of contouring on endwall heat transfer performance of a high-turning high-pressure (HP) turbine blade passage operating under transonic exit conditions. The paper describes comparison of heat transfer performance of two contoured endwall geometries, one aerodynamically optimized (AO) and the other heat transfer optimized (HTO), with a baseline, noncontoured geometry. The endwall geometries were experimentally investigated at Virginia Tech's transient, blow down, transonic linear cascade facility at three exit Mach numbers, Mex= 0.71, 0.88(design) and 0.95, for their heat transfer performance. Endwall surface temperatures were measured using infrared (IR) thermography and local heat transfer coefficient (HTC) values were calculated using measured temperatures. A Camera Matrix model-based data postprocessing technique was developed to relate the two-dimensional images captured by IR Camera to three-dimensional endwall contours. The measurement technique and the methodology for postprocessing of the heat transfer coefficient data have been presented in detail. Discussion and interpretation of experimental results have been augmented using aerodynamic CFD simulations of the geometries. Both the contoured endwalls demonstrated a significant reduction in the overall average heat transfer coefficient values of the order of 10%. The surface Stanton number distributions also indicated a reduction in the level of hot spots for most of the endwall surface. However, at some locations an increase was also observed, especially in the area near the leading edge (LE). The results indicate that the endwall contouring could significantly improve heat transfer performance of turbine passages.
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Effect of Endwall Contouring on a Transonic Turbine Blade Passage: Part 2 — Heat Transfer Performance
Volume 4: Heat Transfer Parts A and B, 2012Co-Authors: Kapil Panchal, Santosh Abraham, Srinath V. Ekkad, Andrew S. Lohaus, Michael E. CrawfordAbstract:Contouring of turbine endwalls has been widely studied for aerodynamic performance improvement of turbine passages. However, it is equally important to investigate the effect of contouring on endwall heat transfer, because a substantial increase in endwall heat transfer due to contouring will render the design impractical. In this paper, the effect of contouring on endwall heat transfer performance of a high-turning HP-turbine blade passage, operating under transonic exit Mach number conditions, is reported. Three endwall geometries were experimentally investigated at three different passage exit Mach numbers, 0.71, 0.88(design) and 0.95, for their heat transfer performance. One endwall is a non-contoured baseline endwall and the other two are contoured endwall geometries. One of the contoured endwall geometry was generated with the goal of reduction in stagnation pressure losses and the other was generated with the goal of reduced overall heat transfer through the endwall. The experiments were carried out in Virginia Tech’s transient, blow down, transonic linear cascade facility. Endwall surface temperatures were measured using infrared thermography technique. Local heat transfer coefficient values were calculated using the measured temperatures. The heat transfer coefficient values were then related to the endwall geometries using a Camera Matrix model. The measurement technique and the methodology for the post-processing of the heat transfer coefficient data have been presented in detail. Details of the flow behavior for these endwalls were obtained using CFD simulations and have been used to assist the interpretation of the experimental results. In this study, the heat transfer performance of the contoured endwalls in comparison to the non-contoured baseline case is presented. Both the contoured endwalls demonstrated a significant reduction in the overall average heat transfer coefficient values. The surface heat transfer coefficient distributions also indicated a reduction in the level of hot spots for most of the endwall surface. However, increase in the heat transfer coefficient values was observed especially in the area near the leading edge. The results indicate that, in addition to a probable improvement in aerodynamic performance, endwall contouring may also be used to improve the heat transfer performance of turbine passages. Additionally, aerodynamic behavior of these endwalls is discussed in detail in the companion paper GT2012-68425, “Effect of endwall contouring on a transonic turbine endwall: Part 1 – Aerodynamic performance.”Copyright © 2012 by Siemens Energy, Inc.
Kapil Panchal - One of the best experts on this subject based on the ideXlab platform.
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Effect of Endwall Contouring on a Transonic Turbine Blade Passage: Heat Transfer Performance
Journal of Turbomachinery, 2016Co-Authors: Kapil Panchal, Santosh Abraham, Arnab Roy, Srinath V. Ekkad, Andrew S. Lohaus, Michael E. CrawfordAbstract:Effect of turbine endwall contouring on its aerodynamic performance has been widely studied, but only a few studies are available in the open literature investigating its effect on heat transfer performance; especially at transonic exit Mach number conditions. In this paper, we report a study of effect of contouring on endwall heat transfer performance of a high-turning high-pressure (HP) turbine blade passage operating under transonic exit conditions. The paper describes comparison of heat transfer performance of two contoured endwall geometries, one aerodynamically optimized (AO) and the other heat transfer optimized (HTO), with a baseline, noncontoured geometry. The endwall geometries were experimentally investigated at Virginia Tech's transient, blow down, transonic linear cascade facility at three exit Mach numbers, Mex= 0.71, 0.88(design) and 0.95, for their heat transfer performance. Endwall surface temperatures were measured using infrared (IR) thermography and local heat transfer coefficient (HTC) values were calculated using measured temperatures. A Camera Matrix model-based data postprocessing technique was developed to relate the two-dimensional images captured by IR Camera to three-dimensional endwall contours. The measurement technique and the methodology for postprocessing of the heat transfer coefficient data have been presented in detail. Discussion and interpretation of experimental results have been augmented using aerodynamic CFD simulations of the geometries. Both the contoured endwalls demonstrated a significant reduction in the overall average heat transfer coefficient values of the order of 10%. The surface Stanton number distributions also indicated a reduction in the level of hot spots for most of the endwall surface. However, at some locations an increase was also observed, especially in the area near the leading edge (LE). The results indicate that the endwall contouring could significantly improve heat transfer performance of turbine passages.
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Effect of Endwall Contouring on a Transonic Turbine Blade Passage: Part 2 — Heat Transfer Performance
Volume 4: Heat Transfer Parts A and B, 2012Co-Authors: Kapil Panchal, Santosh Abraham, Srinath V. Ekkad, Andrew S. Lohaus, Michael E. CrawfordAbstract:Contouring of turbine endwalls has been widely studied for aerodynamic performance improvement of turbine passages. However, it is equally important to investigate the effect of contouring on endwall heat transfer, because a substantial increase in endwall heat transfer due to contouring will render the design impractical. In this paper, the effect of contouring on endwall heat transfer performance of a high-turning HP-turbine blade passage, operating under transonic exit Mach number conditions, is reported. Three endwall geometries were experimentally investigated at three different passage exit Mach numbers, 0.71, 0.88(design) and 0.95, for their heat transfer performance. One endwall is a non-contoured baseline endwall and the other two are contoured endwall geometries. One of the contoured endwall geometry was generated with the goal of reduction in stagnation pressure losses and the other was generated with the goal of reduced overall heat transfer through the endwall. The experiments were carried out in Virginia Tech’s transient, blow down, transonic linear cascade facility. Endwall surface temperatures were measured using infrared thermography technique. Local heat transfer coefficient values were calculated using the measured temperatures. The heat transfer coefficient values were then related to the endwall geometries using a Camera Matrix model. The measurement technique and the methodology for the post-processing of the heat transfer coefficient data have been presented in detail. Details of the flow behavior for these endwalls were obtained using CFD simulations and have been used to assist the interpretation of the experimental results. In this study, the heat transfer performance of the contoured endwalls in comparison to the non-contoured baseline case is presented. Both the contoured endwalls demonstrated a significant reduction in the overall average heat transfer coefficient values. The surface heat transfer coefficient distributions also indicated a reduction in the level of hot spots for most of the endwall surface. However, increase in the heat transfer coefficient values was observed especially in the area near the leading edge. The results indicate that, in addition to a probable improvement in aerodynamic performance, endwall contouring may also be used to improve the heat transfer performance of turbine passages. Additionally, aerodynamic behavior of these endwalls is discussed in detail in the companion paper GT2012-68425, “Effect of endwall contouring on a transonic turbine endwall: Part 1 – Aerodynamic performance.”Copyright © 2012 by Siemens Energy, Inc.
Sung-ryul Noh - One of the best experts on this subject based on the ideXlab platform.
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PCM (1) - Virtual object placement in video for augmented reality
Advances in Multimedia Information Processing - PCM 2005, 2005Co-Authors: Jong-seung Park, Mee Young Sung, Sung-ryul NohAbstract:This article describes a method to insert virtual objects into a real video stream based on feature tracking and Camera pose estimation from a set of single-Camera video frames. To insert or modify 3D shapes to target video frames, the transformation from the 3D objects to the projection of the objects onto the video frames should be revealed. It is shown that, without a Camera calibration process, the 3D reconstruction is possible using multiple images from a single Camera under the fixed internal Camera parameters. The proposed approach is based on the simplification of the Camera Matrix of intrinsic parameters and the use of projective geometry. The method is particularly useful for augmented reality applications to insert or modify models to a real video stream. Several experimental results are presented on real-world video streams, demonstrating the usefulness of our method for the augmented reality applications.
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Virtual object placement in video for augmented reality
Lecture Notes in Computer Science, 2005Co-Authors: Jong-seung Park, Mee Young Sung, Sung-ryul NohAbstract:This article describes a method to insert virtual objects into a real video stream based on feature tracking and Camera pose estimation from a set of single-Camera video frames. To insert or modify 3D shapes to target video frames, the transformation from the 3D objects to the projection of the objects onto the video frames should be revealed. It is shown that, without a Camera calibration process, the 3D reconstruction is possible using multiple images from a single Camera under the fixed internal Camera parameters. The proposed approach is based on the simplification of the Camera Matrix of intrinsic parameters and the use of projective geometry. The method is particularly useful for augmented reality applications to insert or modify models to a real video stream. Several experimental results are presented on real-world video streams, demonstrating the usefulness of our method for the augmented reality applications.
Andrew S. Lohaus - One of the best experts on this subject based on the ideXlab platform.
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Effect of Endwall Contouring on a Transonic Turbine Blade Passage: Heat Transfer Performance
Journal of Turbomachinery, 2016Co-Authors: Kapil Panchal, Santosh Abraham, Arnab Roy, Srinath V. Ekkad, Andrew S. Lohaus, Michael E. CrawfordAbstract:Effect of turbine endwall contouring on its aerodynamic performance has been widely studied, but only a few studies are available in the open literature investigating its effect on heat transfer performance; especially at transonic exit Mach number conditions. In this paper, we report a study of effect of contouring on endwall heat transfer performance of a high-turning high-pressure (HP) turbine blade passage operating under transonic exit conditions. The paper describes comparison of heat transfer performance of two contoured endwall geometries, one aerodynamically optimized (AO) and the other heat transfer optimized (HTO), with a baseline, noncontoured geometry. The endwall geometries were experimentally investigated at Virginia Tech's transient, blow down, transonic linear cascade facility at three exit Mach numbers, Mex= 0.71, 0.88(design) and 0.95, for their heat transfer performance. Endwall surface temperatures were measured using infrared (IR) thermography and local heat transfer coefficient (HTC) values were calculated using measured temperatures. A Camera Matrix model-based data postprocessing technique was developed to relate the two-dimensional images captured by IR Camera to three-dimensional endwall contours. The measurement technique and the methodology for postprocessing of the heat transfer coefficient data have been presented in detail. Discussion and interpretation of experimental results have been augmented using aerodynamic CFD simulations of the geometries. Both the contoured endwalls demonstrated a significant reduction in the overall average heat transfer coefficient values of the order of 10%. The surface Stanton number distributions also indicated a reduction in the level of hot spots for most of the endwall surface. However, at some locations an increase was also observed, especially in the area near the leading edge (LE). The results indicate that the endwall contouring could significantly improve heat transfer performance of turbine passages.
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Effect of Endwall Contouring on a Transonic Turbine Blade Passage: Part 2 — Heat Transfer Performance
Volume 4: Heat Transfer Parts A and B, 2012Co-Authors: Kapil Panchal, Santosh Abraham, Srinath V. Ekkad, Andrew S. Lohaus, Michael E. CrawfordAbstract:Contouring of turbine endwalls has been widely studied for aerodynamic performance improvement of turbine passages. However, it is equally important to investigate the effect of contouring on endwall heat transfer, because a substantial increase in endwall heat transfer due to contouring will render the design impractical. In this paper, the effect of contouring on endwall heat transfer performance of a high-turning HP-turbine blade passage, operating under transonic exit Mach number conditions, is reported. Three endwall geometries were experimentally investigated at three different passage exit Mach numbers, 0.71, 0.88(design) and 0.95, for their heat transfer performance. One endwall is a non-contoured baseline endwall and the other two are contoured endwall geometries. One of the contoured endwall geometry was generated with the goal of reduction in stagnation pressure losses and the other was generated with the goal of reduced overall heat transfer through the endwall. The experiments were carried out in Virginia Tech’s transient, blow down, transonic linear cascade facility. Endwall surface temperatures were measured using infrared thermography technique. Local heat transfer coefficient values were calculated using the measured temperatures. The heat transfer coefficient values were then related to the endwall geometries using a Camera Matrix model. The measurement technique and the methodology for the post-processing of the heat transfer coefficient data have been presented in detail. Details of the flow behavior for these endwalls were obtained using CFD simulations and have been used to assist the interpretation of the experimental results. In this study, the heat transfer performance of the contoured endwalls in comparison to the non-contoured baseline case is presented. Both the contoured endwalls demonstrated a significant reduction in the overall average heat transfer coefficient values. The surface heat transfer coefficient distributions also indicated a reduction in the level of hot spots for most of the endwall surface. However, increase in the heat transfer coefficient values was observed especially in the area near the leading edge. The results indicate that, in addition to a probable improvement in aerodynamic performance, endwall contouring may also be used to improve the heat transfer performance of turbine passages. Additionally, aerodynamic behavior of these endwalls is discussed in detail in the companion paper GT2012-68425, “Effect of endwall contouring on a transonic turbine endwall: Part 1 – Aerodynamic performance.”Copyright © 2012 by Siemens Energy, Inc.
Srinath V. Ekkad - One of the best experts on this subject based on the ideXlab platform.
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Effect of Endwall Contouring on a Transonic Turbine Blade Passage: Heat Transfer Performance
Journal of Turbomachinery, 2016Co-Authors: Kapil Panchal, Santosh Abraham, Arnab Roy, Srinath V. Ekkad, Andrew S. Lohaus, Michael E. CrawfordAbstract:Effect of turbine endwall contouring on its aerodynamic performance has been widely studied, but only a few studies are available in the open literature investigating its effect on heat transfer performance; especially at transonic exit Mach number conditions. In this paper, we report a study of effect of contouring on endwall heat transfer performance of a high-turning high-pressure (HP) turbine blade passage operating under transonic exit conditions. The paper describes comparison of heat transfer performance of two contoured endwall geometries, one aerodynamically optimized (AO) and the other heat transfer optimized (HTO), with a baseline, noncontoured geometry. The endwall geometries were experimentally investigated at Virginia Tech's transient, blow down, transonic linear cascade facility at three exit Mach numbers, Mex= 0.71, 0.88(design) and 0.95, for their heat transfer performance. Endwall surface temperatures were measured using infrared (IR) thermography and local heat transfer coefficient (HTC) values were calculated using measured temperatures. A Camera Matrix model-based data postprocessing technique was developed to relate the two-dimensional images captured by IR Camera to three-dimensional endwall contours. The measurement technique and the methodology for postprocessing of the heat transfer coefficient data have been presented in detail. Discussion and interpretation of experimental results have been augmented using aerodynamic CFD simulations of the geometries. Both the contoured endwalls demonstrated a significant reduction in the overall average heat transfer coefficient values of the order of 10%. The surface Stanton number distributions also indicated a reduction in the level of hot spots for most of the endwall surface. However, at some locations an increase was also observed, especially in the area near the leading edge (LE). The results indicate that the endwall contouring could significantly improve heat transfer performance of turbine passages.
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Effect of Endwall Contouring on a Transonic Turbine Blade Passage: Part 2 — Heat Transfer Performance
Volume 4: Heat Transfer Parts A and B, 2012Co-Authors: Kapil Panchal, Santosh Abraham, Srinath V. Ekkad, Andrew S. Lohaus, Michael E. CrawfordAbstract:Contouring of turbine endwalls has been widely studied for aerodynamic performance improvement of turbine passages. However, it is equally important to investigate the effect of contouring on endwall heat transfer, because a substantial increase in endwall heat transfer due to contouring will render the design impractical. In this paper, the effect of contouring on endwall heat transfer performance of a high-turning HP-turbine blade passage, operating under transonic exit Mach number conditions, is reported. Three endwall geometries were experimentally investigated at three different passage exit Mach numbers, 0.71, 0.88(design) and 0.95, for their heat transfer performance. One endwall is a non-contoured baseline endwall and the other two are contoured endwall geometries. One of the contoured endwall geometry was generated with the goal of reduction in stagnation pressure losses and the other was generated with the goal of reduced overall heat transfer through the endwall. The experiments were carried out in Virginia Tech’s transient, blow down, transonic linear cascade facility. Endwall surface temperatures were measured using infrared thermography technique. Local heat transfer coefficient values were calculated using the measured temperatures. The heat transfer coefficient values were then related to the endwall geometries using a Camera Matrix model. The measurement technique and the methodology for the post-processing of the heat transfer coefficient data have been presented in detail. Details of the flow behavior for these endwalls were obtained using CFD simulations and have been used to assist the interpretation of the experimental results. In this study, the heat transfer performance of the contoured endwalls in comparison to the non-contoured baseline case is presented. Both the contoured endwalls demonstrated a significant reduction in the overall average heat transfer coefficient values. The surface heat transfer coefficient distributions also indicated a reduction in the level of hot spots for most of the endwall surface. However, increase in the heat transfer coefficient values was observed especially in the area near the leading edge. The results indicate that, in addition to a probable improvement in aerodynamic performance, endwall contouring may also be used to improve the heat transfer performance of turbine passages. Additionally, aerodynamic behavior of these endwalls is discussed in detail in the companion paper GT2012-68425, “Effect of endwall contouring on a transonic turbine endwall: Part 1 – Aerodynamic performance.”Copyright © 2012 by Siemens Energy, Inc.
