The Experts below are selected from a list of 324 Experts worldwide ranked by ideXlab platform

Michael G. Dunn - One of the best experts on this subject based on the ideXlab platform.

  • Heat-Flux Measurements and Predictions for the Blade Tip Region of a High-Pressure Turbine
    Volume 3: Heat Transfer Parts A and B, 2006
    Co-Authors: S. M. Molter, Charles W. Haldeman, Michael G. Dunn, Robert Frederick Bergholz, P. Vitt
    Abstract:

    High-Pressure Turbine blade tips operate in a highly complex flow environment that makes designing new blades for increased life difficult. Computational fluid dynamics simulations of the tip flow field may be able to guide new designs to improve the blade life, but the analysis techniques need to be verified against detailed measurements before they can be applied. The current paper presents measurements of heat flux and pressure in the blade tip region of a modern one-and-one-half stage High-Pressure Turbine operating at design corrected conditions in a rotating rig. Both flat tip and recessed, or squealer, tip blades were used in the experiments. The measurements indicate that the recessed tip, used in the majority of modern Turbines to minimize blade damage from rubs, increases the blade heat load overall, and creates several hot spots on the floor of the recess for an uncooled airfoil. The tip data also showed there were significant unsteady variations in the heat load at the vane passing frequency. Steady state CFD calculations were completed for both flat and squealer tip configurations to examine if the analysis could capture the details that were measured. The CFD, while not capable of estimating the unsteady heat load component and generally over predicting the overall heat flux by 10–25%, did capture the measured heat flux trends in the recessed tip. These results show that steady-state CFD analysis can be useful in predicting the complex flow field and heat load distribution in Turbine blade tips to help guide future blade designs.Copyright © 2006 by ASME

  • Design, Construction, and Operation of a Combustor Emulator for Short-Duration High-Pressure Turbine Experiments
    40th AIAA ASME SAE ASEE Joint Propulsion Conference and Exhibit, 2004
    Co-Authors: Charles W. Haldeman, Randall M. Mathison, Michael G. Dunn
    Abstract:

    Short-duration facilities have proven to be very adept at creating uniform inlet conditions for full-scale rotating Turbine rigs to create experimental data sets used for design code verification. However, it has been well known that the inlet to the High-Pressure Turbine stage in an engine is anything but uniform, and as codes have improved, it has become clear that reproducing these inlet conditions is critical to proper modeling. To aid in this work, a combustor emulator has been designed and constructed that allows the user to create a variety of temperature profiles (radial, circumferential, pure hot streak) that are used to modify the inlet conditions to a High-Pressure Turbine stage operating at corrected engine conditions. This emulator differs from past designs in that it allows for changes in the number of circumferential “hot-streaks”, the circumferential location of these hotstreaks, as well as their radial locations. These are usually chosen to mimic the number of combustor nozzles in a real engine (between 15 and 20) so that one can model the clocking interactions between the hot spots and the HPT vane. The data presented in this paper shows the different types of temperature profiles that can be obtained with this device and compares the predicted design characteristics of the temperature profiles to the experimentally observed properties.

  • Experimental Investigation of Vane Clocking in a One and One-Half Stage High Pressure Turbine
    Journal of Turbomachinery, 2004
    Co-Authors: Charles W. Haldeman, Michael G. Dunn, John W. Barter, Brian R. Green, Robert Frederick Bergholz
    Abstract:

    Aerodynamic measurements were acquired on a modern single-stage, transonic, High-Pressure Turbine with the adjacent low-pressure Turbine vane row (a typical civilian one and one-half stage Turbine rig) to observe the effects of low-pressure Turbine vane clocking on overall Turbine performance. The Turbine rig (loosely referred to in this paper as the stage) was operated at design corrected conditions using the Ohio State University Gas Turbine Laboratory Turbine Test Facility. The research program utilized uncooled hardware in which all three airfoils were heavily instrumented at multiple spans to develop a full clocking dataset. The low-pressure Turbine vane row (LPTV) was clocked relative to the High-Pressure Turbine vane row (HPTV). Various methods were used to evaluate the influence of clocking on the aeroperformance (efficiency) and the aerodynamics (pressure loading) of the LPTV, including time-resolved and time-averaged measurements. A change in overall efficiency of approximately 2-3% due to clocking effects is demonstrated and could be observed using a variety of independent methods. Maximum efficiency is obtained when the time-average surface pressures are highest on the LPTV and the time-resolved surface pressure (both in the time domain and frequency domain) show the least amount of variation. The overall effect is obtained by integrating over the entire airfoil, as the three-dimensional (3D) effects on the LPTV surface are significant. This experimental data set validates several computational research efforts that suggested wake migration is the primary reason for the perceived effectiveness of vane clocking. The suggestion that wake migration is the dominate mechanism in generating the clocking effect is also consistent with anecdotal evidence that fully cooled engine rigs do not see a great deal of clocking effect. This is consistent since the additional disturbances induced by the cooling flows and/or the combustor make it extremely difficult to find an alignment for the LPTV given the strong 3D nature of modern High-Pressure Turbine flows.

  • Averaged and Time-Dependent Aerodynamics of a High Pressure Turbine Blade Tip Cavity and Stationary Shroud: Comparison of Computational and Experimental Results
    Journal of Turbomachinery, 2004
    Co-Authors: Brian R. Green, Charles W. Haldeman, John W. Barter, Michael G. Dunn
    Abstract:

    The unsteady aero-dynamics of a single-stage High-Pressure Turbine blade operating at design corrected conditions has been the subject of a thorough study involving detailed measurements and computations. The experimental configuration consisted of a single-stage High-Pressure Turbine and the adjacent, downstream, low-pressure Turbine nozzle row. All three blade-rows were instrumented at three spanwise locations with flush-mounted, high-frequency response pressure transducers. The rotor was also instrumented with the same transducers on the blade tip and platform and the stationary shroud was instrumented with pressure transducers at specific locations above the rotating blade. Predictions of the time-dependent flow field around the rotor were obtained using MSU-TURBO, a three-dimensional (3D), nonlinear, computational fluid dynamics (CFD) code. Using an isolated blade-row unsteady analysis method, the unsteady surface pressure for the High-Pressure Turbine rotor due to the upstream High-Pressure Turbine nozzle was calculated. The predicted unsteady pressure on the rotor surface was compared to the measurements at selected spanwise locations on the blade, in the recessed cavity, and on the shroud. The rig and computational models included a flat and recessed blade tip geometry and were used fbr the comparisons presented in the paper. Comparisons of the measured and predicted static pressure loading on the blade surface show excellent correlation from both a time-average and time-accurate standpoint. This paper concentrates on the tip and shroud comparisons between the experiments and the predictions and these results also show good correlation with the time-resolved data. These data comparisons provide confidence in the CFD modeling and its ability to capture unsteady flow physics on the blade surface, in the flat and recessed tip regions of the blade, and on the stationary shroud.

  • Experimental Investigation of Vane Clocking in a One and 1/2 Stage High Pressure Turbine
    Volume 5: Turbo Expo 2004 Parts A and B, 2004
    Co-Authors: Charles W. Haldeman, Michael G. Dunn, John W. Barter, Brian R. Green, Robert Frederick Bergholz
    Abstract:

    Aerodynamic measurements were acquired on a modern single-stage, transonic, High-Pressure Turbine with the adjacent low-pressure Turbine vane row (a typical civilian one and one-half stage Turbine rig) to observe the effects of low-pressure Turbine vane clocking on overall Turbine performance. The Turbine rig (loosely referred to in this paper as the stage) was operated at design corrected conditions using the Ohio State University Gas Turbine Laboratory Turbine Test Facility (TTF). The research program utilized uncooled hardware in which all three airfoils were heavily instrumented at multiple spans to develop a full clocking dataset. The low-pressure Turbine vane row (LPTV) was clocked relative to the High-Pressure Turbine vane row (HPTV). Various methods were used to evaluate the influence of clocking on the aeroperformance (efficiency) and the aerodynamics (pressure loading) of the LPTV, including time-resolved and time-averaged measurements. A change in overall efficiency of approximately 2–3% due to clocking effects is demonstrated and could be observed using a variety of independent methods. Maximum efficiency is obtained when the time-average surface pressures are highest on the LPTV and the time-resolved surface pressure (both in the time domain and frequency domain) show the least amount of variation. The overall effect is obtained by integrating over the entire airfoil, as the three-dimensional effects on the LPTV surface are significant. This experimental data set validates several computational research efforts that suggested wake migration is the primary reason for the perceived effectiveness of vane clocking. The suggestion that wake migration is the dominate mechanism in generating the clocking effect is also consistent with anecdotal evidence that fully cooled engine rigs do not see a great deal of clocking effect. This is consistent since the additional disturbances induced by the cooling flows and/or the combustor make it extremely difficult to find an alignment for the LPTV given the strong 3D nature of modern High-Pressure Turbine flows.Copyright © 2004 by ASME

Charles W. Haldeman - One of the best experts on this subject based on the ideXlab platform.

  • Heat-Flux Measurements and Predictions for the Blade Tip Region of a High-Pressure Turbine
    Volume 3: Heat Transfer Parts A and B, 2006
    Co-Authors: S. M. Molter, Charles W. Haldeman, Michael G. Dunn, Robert Frederick Bergholz, P. Vitt
    Abstract:

    High-Pressure Turbine blade tips operate in a highly complex flow environment that makes designing new blades for increased life difficult. Computational fluid dynamics simulations of the tip flow field may be able to guide new designs to improve the blade life, but the analysis techniques need to be verified against detailed measurements before they can be applied. The current paper presents measurements of heat flux and pressure in the blade tip region of a modern one-and-one-half stage High-Pressure Turbine operating at design corrected conditions in a rotating rig. Both flat tip and recessed, or squealer, tip blades were used in the experiments. The measurements indicate that the recessed tip, used in the majority of modern Turbines to minimize blade damage from rubs, increases the blade heat load overall, and creates several hot spots on the floor of the recess for an uncooled airfoil. The tip data also showed there were significant unsteady variations in the heat load at the vane passing frequency. Steady state CFD calculations were completed for both flat and squealer tip configurations to examine if the analysis could capture the details that were measured. The CFD, while not capable of estimating the unsteady heat load component and generally over predicting the overall heat flux by 10–25%, did capture the measured heat flux trends in the recessed tip. These results show that steady-state CFD analysis can be useful in predicting the complex flow field and heat load distribution in Turbine blade tips to help guide future blade designs.Copyright © 2006 by ASME

  • Design, Construction, and Operation of a Combustor Emulator for Short-Duration High-Pressure Turbine Experiments
    40th AIAA ASME SAE ASEE Joint Propulsion Conference and Exhibit, 2004
    Co-Authors: Charles W. Haldeman, Randall M. Mathison, Michael G. Dunn
    Abstract:

    Short-duration facilities have proven to be very adept at creating uniform inlet conditions for full-scale rotating Turbine rigs to create experimental data sets used for design code verification. However, it has been well known that the inlet to the High-Pressure Turbine stage in an engine is anything but uniform, and as codes have improved, it has become clear that reproducing these inlet conditions is critical to proper modeling. To aid in this work, a combustor emulator has been designed and constructed that allows the user to create a variety of temperature profiles (radial, circumferential, pure hot streak) that are used to modify the inlet conditions to a High-Pressure Turbine stage operating at corrected engine conditions. This emulator differs from past designs in that it allows for changes in the number of circumferential “hot-streaks”, the circumferential location of these hotstreaks, as well as their radial locations. These are usually chosen to mimic the number of combustor nozzles in a real engine (between 15 and 20) so that one can model the clocking interactions between the hot spots and the HPT vane. The data presented in this paper shows the different types of temperature profiles that can be obtained with this device and compares the predicted design characteristics of the temperature profiles to the experimentally observed properties.

  • Experimental Investigation of Vane Clocking in a One and One-Half Stage High Pressure Turbine
    Journal of Turbomachinery, 2004
    Co-Authors: Charles W. Haldeman, Michael G. Dunn, John W. Barter, Brian R. Green, Robert Frederick Bergholz
    Abstract:

    Aerodynamic measurements were acquired on a modern single-stage, transonic, High-Pressure Turbine with the adjacent low-pressure Turbine vane row (a typical civilian one and one-half stage Turbine rig) to observe the effects of low-pressure Turbine vane clocking on overall Turbine performance. The Turbine rig (loosely referred to in this paper as the stage) was operated at design corrected conditions using the Ohio State University Gas Turbine Laboratory Turbine Test Facility. The research program utilized uncooled hardware in which all three airfoils were heavily instrumented at multiple spans to develop a full clocking dataset. The low-pressure Turbine vane row (LPTV) was clocked relative to the High-Pressure Turbine vane row (HPTV). Various methods were used to evaluate the influence of clocking on the aeroperformance (efficiency) and the aerodynamics (pressure loading) of the LPTV, including time-resolved and time-averaged measurements. A change in overall efficiency of approximately 2-3% due to clocking effects is demonstrated and could be observed using a variety of independent methods. Maximum efficiency is obtained when the time-average surface pressures are highest on the LPTV and the time-resolved surface pressure (both in the time domain and frequency domain) show the least amount of variation. The overall effect is obtained by integrating over the entire airfoil, as the three-dimensional (3D) effects on the LPTV surface are significant. This experimental data set validates several computational research efforts that suggested wake migration is the primary reason for the perceived effectiveness of vane clocking. The suggestion that wake migration is the dominate mechanism in generating the clocking effect is also consistent with anecdotal evidence that fully cooled engine rigs do not see a great deal of clocking effect. This is consistent since the additional disturbances induced by the cooling flows and/or the combustor make it extremely difficult to find an alignment for the LPTV given the strong 3D nature of modern High-Pressure Turbine flows.

  • Averaged and Time-Dependent Aerodynamics of a High Pressure Turbine Blade Tip Cavity and Stationary Shroud: Comparison of Computational and Experimental Results
    Journal of Turbomachinery, 2004
    Co-Authors: Brian R. Green, Charles W. Haldeman, John W. Barter, Michael G. Dunn
    Abstract:

    The unsteady aero-dynamics of a single-stage High-Pressure Turbine blade operating at design corrected conditions has been the subject of a thorough study involving detailed measurements and computations. The experimental configuration consisted of a single-stage High-Pressure Turbine and the adjacent, downstream, low-pressure Turbine nozzle row. All three blade-rows were instrumented at three spanwise locations with flush-mounted, high-frequency response pressure transducers. The rotor was also instrumented with the same transducers on the blade tip and platform and the stationary shroud was instrumented with pressure transducers at specific locations above the rotating blade. Predictions of the time-dependent flow field around the rotor were obtained using MSU-TURBO, a three-dimensional (3D), nonlinear, computational fluid dynamics (CFD) code. Using an isolated blade-row unsteady analysis method, the unsteady surface pressure for the High-Pressure Turbine rotor due to the upstream High-Pressure Turbine nozzle was calculated. The predicted unsteady pressure on the rotor surface was compared to the measurements at selected spanwise locations on the blade, in the recessed cavity, and on the shroud. The rig and computational models included a flat and recessed blade tip geometry and were used fbr the comparisons presented in the paper. Comparisons of the measured and predicted static pressure loading on the blade surface show excellent correlation from both a time-average and time-accurate standpoint. This paper concentrates on the tip and shroud comparisons between the experiments and the predictions and these results also show good correlation with the time-resolved data. These data comparisons provide confidence in the CFD modeling and its ability to capture unsteady flow physics on the blade surface, in the flat and recessed tip regions of the blade, and on the stationary shroud.

  • Experimental Investigation of Vane Clocking in a One and 1/2 Stage High Pressure Turbine
    Volume 5: Turbo Expo 2004 Parts A and B, 2004
    Co-Authors: Charles W. Haldeman, Michael G. Dunn, John W. Barter, Brian R. Green, Robert Frederick Bergholz
    Abstract:

    Aerodynamic measurements were acquired on a modern single-stage, transonic, High-Pressure Turbine with the adjacent low-pressure Turbine vane row (a typical civilian one and one-half stage Turbine rig) to observe the effects of low-pressure Turbine vane clocking on overall Turbine performance. The Turbine rig (loosely referred to in this paper as the stage) was operated at design corrected conditions using the Ohio State University Gas Turbine Laboratory Turbine Test Facility (TTF). The research program utilized uncooled hardware in which all three airfoils were heavily instrumented at multiple spans to develop a full clocking dataset. The low-pressure Turbine vane row (LPTV) was clocked relative to the High-Pressure Turbine vane row (HPTV). Various methods were used to evaluate the influence of clocking on the aeroperformance (efficiency) and the aerodynamics (pressure loading) of the LPTV, including time-resolved and time-averaged measurements. A change in overall efficiency of approximately 2–3% due to clocking effects is demonstrated and could be observed using a variety of independent methods. Maximum efficiency is obtained when the time-average surface pressures are highest on the LPTV and the time-resolved surface pressure (both in the time domain and frequency domain) show the least amount of variation. The overall effect is obtained by integrating over the entire airfoil, as the three-dimensional effects on the LPTV surface are significant. This experimental data set validates several computational research efforts that suggested wake migration is the primary reason for the perceived effectiveness of vane clocking. The suggestion that wake migration is the dominate mechanism in generating the clocking effect is also consistent with anecdotal evidence that fully cooled engine rigs do not see a great deal of clocking effect. This is consistent since the additional disturbances induced by the cooling flows and/or the combustor make it extremely difficult to find an alignment for the LPTV given the strong 3D nature of modern High-Pressure Turbine flows.Copyright © 2004 by ASME

Brian R. Green - One of the best experts on this subject based on the ideXlab platform.

  • Experimental Investigation of Vane Clocking in a One and One-Half Stage High Pressure Turbine
    Journal of Turbomachinery, 2004
    Co-Authors: Charles W. Haldeman, Michael G. Dunn, John W. Barter, Brian R. Green, Robert Frederick Bergholz
    Abstract:

    Aerodynamic measurements were acquired on a modern single-stage, transonic, High-Pressure Turbine with the adjacent low-pressure Turbine vane row (a typical civilian one and one-half stage Turbine rig) to observe the effects of low-pressure Turbine vane clocking on overall Turbine performance. The Turbine rig (loosely referred to in this paper as the stage) was operated at design corrected conditions using the Ohio State University Gas Turbine Laboratory Turbine Test Facility. The research program utilized uncooled hardware in which all three airfoils were heavily instrumented at multiple spans to develop a full clocking dataset. The low-pressure Turbine vane row (LPTV) was clocked relative to the High-Pressure Turbine vane row (HPTV). Various methods were used to evaluate the influence of clocking on the aeroperformance (efficiency) and the aerodynamics (pressure loading) of the LPTV, including time-resolved and time-averaged measurements. A change in overall efficiency of approximately 2-3% due to clocking effects is demonstrated and could be observed using a variety of independent methods. Maximum efficiency is obtained when the time-average surface pressures are highest on the LPTV and the time-resolved surface pressure (both in the time domain and frequency domain) show the least amount of variation. The overall effect is obtained by integrating over the entire airfoil, as the three-dimensional (3D) effects on the LPTV surface are significant. This experimental data set validates several computational research efforts that suggested wake migration is the primary reason for the perceived effectiveness of vane clocking. The suggestion that wake migration is the dominate mechanism in generating the clocking effect is also consistent with anecdotal evidence that fully cooled engine rigs do not see a great deal of clocking effect. This is consistent since the additional disturbances induced by the cooling flows and/or the combustor make it extremely difficult to find an alignment for the LPTV given the strong 3D nature of modern High-Pressure Turbine flows.

  • Averaged and Time-Dependent Aerodynamics of a High Pressure Turbine Blade Tip Cavity and Stationary Shroud: Comparison of Computational and Experimental Results
    Journal of Turbomachinery, 2004
    Co-Authors: Brian R. Green, Charles W. Haldeman, John W. Barter, Michael G. Dunn
    Abstract:

    The unsteady aero-dynamics of a single-stage High-Pressure Turbine blade operating at design corrected conditions has been the subject of a thorough study involving detailed measurements and computations. The experimental configuration consisted of a single-stage High-Pressure Turbine and the adjacent, downstream, low-pressure Turbine nozzle row. All three blade-rows were instrumented at three spanwise locations with flush-mounted, high-frequency response pressure transducers. The rotor was also instrumented with the same transducers on the blade tip and platform and the stationary shroud was instrumented with pressure transducers at specific locations above the rotating blade. Predictions of the time-dependent flow field around the rotor were obtained using MSU-TURBO, a three-dimensional (3D), nonlinear, computational fluid dynamics (CFD) code. Using an isolated blade-row unsteady analysis method, the unsteady surface pressure for the High-Pressure Turbine rotor due to the upstream High-Pressure Turbine nozzle was calculated. The predicted unsteady pressure on the rotor surface was compared to the measurements at selected spanwise locations on the blade, in the recessed cavity, and on the shroud. The rig and computational models included a flat and recessed blade tip geometry and were used fbr the comparisons presented in the paper. Comparisons of the measured and predicted static pressure loading on the blade surface show excellent correlation from both a time-average and time-accurate standpoint. This paper concentrates on the tip and shroud comparisons between the experiments and the predictions and these results also show good correlation with the time-resolved data. These data comparisons provide confidence in the CFD modeling and its ability to capture unsteady flow physics on the blade surface, in the flat and recessed tip regions of the blade, and on the stationary shroud.

  • Experimental Investigation of Vane Clocking in a One and 1/2 Stage High Pressure Turbine
    Volume 5: Turbo Expo 2004 Parts A and B, 2004
    Co-Authors: Charles W. Haldeman, Michael G. Dunn, John W. Barter, Brian R. Green, Robert Frederick Bergholz
    Abstract:

    Aerodynamic measurements were acquired on a modern single-stage, transonic, High-Pressure Turbine with the adjacent low-pressure Turbine vane row (a typical civilian one and one-half stage Turbine rig) to observe the effects of low-pressure Turbine vane clocking on overall Turbine performance. The Turbine rig (loosely referred to in this paper as the stage) was operated at design corrected conditions using the Ohio State University Gas Turbine Laboratory Turbine Test Facility (TTF). The research program utilized uncooled hardware in which all three airfoils were heavily instrumented at multiple spans to develop a full clocking dataset. The low-pressure Turbine vane row (LPTV) was clocked relative to the High-Pressure Turbine vane row (HPTV). Various methods were used to evaluate the influence of clocking on the aeroperformance (efficiency) and the aerodynamics (pressure loading) of the LPTV, including time-resolved and time-averaged measurements. A change in overall efficiency of approximately 2–3% due to clocking effects is demonstrated and could be observed using a variety of independent methods. Maximum efficiency is obtained when the time-average surface pressures are highest on the LPTV and the time-resolved surface pressure (both in the time domain and frequency domain) show the least amount of variation. The overall effect is obtained by integrating over the entire airfoil, as the three-dimensional effects on the LPTV surface are significant. This experimental data set validates several computational research efforts that suggested wake migration is the primary reason for the perceived effectiveness of vane clocking. The suggestion that wake migration is the dominate mechanism in generating the clocking effect is also consistent with anecdotal evidence that fully cooled engine rigs do not see a great deal of clocking effect. This is consistent since the additional disturbances induced by the cooling flows and/or the combustor make it extremely difficult to find an alignment for the LPTV given the strong 3D nature of modern High-Pressure Turbine flows.Copyright © 2004 by ASME

Robert Frederick Bergholz - One of the best experts on this subject based on the ideXlab platform.

  • Heat-Flux Measurements and Predictions for the Blade Tip Region of a High-Pressure Turbine
    Volume 3: Heat Transfer Parts A and B, 2006
    Co-Authors: S. M. Molter, Charles W. Haldeman, Michael G. Dunn, Robert Frederick Bergholz, P. Vitt
    Abstract:

    High-Pressure Turbine blade tips operate in a highly complex flow environment that makes designing new blades for increased life difficult. Computational fluid dynamics simulations of the tip flow field may be able to guide new designs to improve the blade life, but the analysis techniques need to be verified against detailed measurements before they can be applied. The current paper presents measurements of heat flux and pressure in the blade tip region of a modern one-and-one-half stage High-Pressure Turbine operating at design corrected conditions in a rotating rig. Both flat tip and recessed, or squealer, tip blades were used in the experiments. The measurements indicate that the recessed tip, used in the majority of modern Turbines to minimize blade damage from rubs, increases the blade heat load overall, and creates several hot spots on the floor of the recess for an uncooled airfoil. The tip data also showed there were significant unsteady variations in the heat load at the vane passing frequency. Steady state CFD calculations were completed for both flat and squealer tip configurations to examine if the analysis could capture the details that were measured. The CFD, while not capable of estimating the unsteady heat load component and generally over predicting the overall heat flux by 10–25%, did capture the measured heat flux trends in the recessed tip. These results show that steady-state CFD analysis can be useful in predicting the complex flow field and heat load distribution in Turbine blade tips to help guide future blade designs.Copyright © 2006 by ASME

  • Experimental Investigation of Vane Clocking in a One and One-Half Stage High Pressure Turbine
    Journal of Turbomachinery, 2004
    Co-Authors: Charles W. Haldeman, Michael G. Dunn, John W. Barter, Brian R. Green, Robert Frederick Bergholz
    Abstract:

    Aerodynamic measurements were acquired on a modern single-stage, transonic, High-Pressure Turbine with the adjacent low-pressure Turbine vane row (a typical civilian one and one-half stage Turbine rig) to observe the effects of low-pressure Turbine vane clocking on overall Turbine performance. The Turbine rig (loosely referred to in this paper as the stage) was operated at design corrected conditions using the Ohio State University Gas Turbine Laboratory Turbine Test Facility. The research program utilized uncooled hardware in which all three airfoils were heavily instrumented at multiple spans to develop a full clocking dataset. The low-pressure Turbine vane row (LPTV) was clocked relative to the High-Pressure Turbine vane row (HPTV). Various methods were used to evaluate the influence of clocking on the aeroperformance (efficiency) and the aerodynamics (pressure loading) of the LPTV, including time-resolved and time-averaged measurements. A change in overall efficiency of approximately 2-3% due to clocking effects is demonstrated and could be observed using a variety of independent methods. Maximum efficiency is obtained when the time-average surface pressures are highest on the LPTV and the time-resolved surface pressure (both in the time domain and frequency domain) show the least amount of variation. The overall effect is obtained by integrating over the entire airfoil, as the three-dimensional (3D) effects on the LPTV surface are significant. This experimental data set validates several computational research efforts that suggested wake migration is the primary reason for the perceived effectiveness of vane clocking. The suggestion that wake migration is the dominate mechanism in generating the clocking effect is also consistent with anecdotal evidence that fully cooled engine rigs do not see a great deal of clocking effect. This is consistent since the additional disturbances induced by the cooling flows and/or the combustor make it extremely difficult to find an alignment for the LPTV given the strong 3D nature of modern High-Pressure Turbine flows.

  • Experimental Investigation of Vane Clocking in a One and 1/2 Stage High Pressure Turbine
    Volume 5: Turbo Expo 2004 Parts A and B, 2004
    Co-Authors: Charles W. Haldeman, Michael G. Dunn, John W. Barter, Brian R. Green, Robert Frederick Bergholz
    Abstract:

    Aerodynamic measurements were acquired on a modern single-stage, transonic, High-Pressure Turbine with the adjacent low-pressure Turbine vane row (a typical civilian one and one-half stage Turbine rig) to observe the effects of low-pressure Turbine vane clocking on overall Turbine performance. The Turbine rig (loosely referred to in this paper as the stage) was operated at design corrected conditions using the Ohio State University Gas Turbine Laboratory Turbine Test Facility (TTF). The research program utilized uncooled hardware in which all three airfoils were heavily instrumented at multiple spans to develop a full clocking dataset. The low-pressure Turbine vane row (LPTV) was clocked relative to the High-Pressure Turbine vane row (HPTV). Various methods were used to evaluate the influence of clocking on the aeroperformance (efficiency) and the aerodynamics (pressure loading) of the LPTV, including time-resolved and time-averaged measurements. A change in overall efficiency of approximately 2–3% due to clocking effects is demonstrated and could be observed using a variety of independent methods. Maximum efficiency is obtained when the time-average surface pressures are highest on the LPTV and the time-resolved surface pressure (both in the time domain and frequency domain) show the least amount of variation. The overall effect is obtained by integrating over the entire airfoil, as the three-dimensional effects on the LPTV surface are significant. This experimental data set validates several computational research efforts that suggested wake migration is the primary reason for the perceived effectiveness of vane clocking. The suggestion that wake migration is the dominate mechanism in generating the clocking effect is also consistent with anecdotal evidence that fully cooled engine rigs do not see a great deal of clocking effect. This is consistent since the additional disturbances induced by the cooling flows and/or the combustor make it extremely difficult to find an alignment for the LPTV given the strong 3D nature of modern High-Pressure Turbine flows.Copyright © 2004 by ASME

John W. Barter - One of the best experts on this subject based on the ideXlab platform.

  • Experimental Investigation of Vane Clocking in a One and One-Half Stage High Pressure Turbine
    Journal of Turbomachinery, 2004
    Co-Authors: Charles W. Haldeman, Michael G. Dunn, John W. Barter, Brian R. Green, Robert Frederick Bergholz
    Abstract:

    Aerodynamic measurements were acquired on a modern single-stage, transonic, High-Pressure Turbine with the adjacent low-pressure Turbine vane row (a typical civilian one and one-half stage Turbine rig) to observe the effects of low-pressure Turbine vane clocking on overall Turbine performance. The Turbine rig (loosely referred to in this paper as the stage) was operated at design corrected conditions using the Ohio State University Gas Turbine Laboratory Turbine Test Facility. The research program utilized uncooled hardware in which all three airfoils were heavily instrumented at multiple spans to develop a full clocking dataset. The low-pressure Turbine vane row (LPTV) was clocked relative to the High-Pressure Turbine vane row (HPTV). Various methods were used to evaluate the influence of clocking on the aeroperformance (efficiency) and the aerodynamics (pressure loading) of the LPTV, including time-resolved and time-averaged measurements. A change in overall efficiency of approximately 2-3% due to clocking effects is demonstrated and could be observed using a variety of independent methods. Maximum efficiency is obtained when the time-average surface pressures are highest on the LPTV and the time-resolved surface pressure (both in the time domain and frequency domain) show the least amount of variation. The overall effect is obtained by integrating over the entire airfoil, as the three-dimensional (3D) effects on the LPTV surface are significant. This experimental data set validates several computational research efforts that suggested wake migration is the primary reason for the perceived effectiveness of vane clocking. The suggestion that wake migration is the dominate mechanism in generating the clocking effect is also consistent with anecdotal evidence that fully cooled engine rigs do not see a great deal of clocking effect. This is consistent since the additional disturbances induced by the cooling flows and/or the combustor make it extremely difficult to find an alignment for the LPTV given the strong 3D nature of modern High-Pressure Turbine flows.

  • Averaged and Time-Dependent Aerodynamics of a High Pressure Turbine Blade Tip Cavity and Stationary Shroud: Comparison of Computational and Experimental Results
    Journal of Turbomachinery, 2004
    Co-Authors: Brian R. Green, Charles W. Haldeman, John W. Barter, Michael G. Dunn
    Abstract:

    The unsteady aero-dynamics of a single-stage High-Pressure Turbine blade operating at design corrected conditions has been the subject of a thorough study involving detailed measurements and computations. The experimental configuration consisted of a single-stage High-Pressure Turbine and the adjacent, downstream, low-pressure Turbine nozzle row. All three blade-rows were instrumented at three spanwise locations with flush-mounted, high-frequency response pressure transducers. The rotor was also instrumented with the same transducers on the blade tip and platform and the stationary shroud was instrumented with pressure transducers at specific locations above the rotating blade. Predictions of the time-dependent flow field around the rotor were obtained using MSU-TURBO, a three-dimensional (3D), nonlinear, computational fluid dynamics (CFD) code. Using an isolated blade-row unsteady analysis method, the unsteady surface pressure for the High-Pressure Turbine rotor due to the upstream High-Pressure Turbine nozzle was calculated. The predicted unsteady pressure on the rotor surface was compared to the measurements at selected spanwise locations on the blade, in the recessed cavity, and on the shroud. The rig and computational models included a flat and recessed blade tip geometry and were used fbr the comparisons presented in the paper. Comparisons of the measured and predicted static pressure loading on the blade surface show excellent correlation from both a time-average and time-accurate standpoint. This paper concentrates on the tip and shroud comparisons between the experiments and the predictions and these results also show good correlation with the time-resolved data. These data comparisons provide confidence in the CFD modeling and its ability to capture unsteady flow physics on the blade surface, in the flat and recessed tip regions of the blade, and on the stationary shroud.

  • Experimental Investigation of Vane Clocking in a One and 1/2 Stage High Pressure Turbine
    Volume 5: Turbo Expo 2004 Parts A and B, 2004
    Co-Authors: Charles W. Haldeman, Michael G. Dunn, John W. Barter, Brian R. Green, Robert Frederick Bergholz
    Abstract:

    Aerodynamic measurements were acquired on a modern single-stage, transonic, High-Pressure Turbine with the adjacent low-pressure Turbine vane row (a typical civilian one and one-half stage Turbine rig) to observe the effects of low-pressure Turbine vane clocking on overall Turbine performance. The Turbine rig (loosely referred to in this paper as the stage) was operated at design corrected conditions using the Ohio State University Gas Turbine Laboratory Turbine Test Facility (TTF). The research program utilized uncooled hardware in which all three airfoils were heavily instrumented at multiple spans to develop a full clocking dataset. The low-pressure Turbine vane row (LPTV) was clocked relative to the High-Pressure Turbine vane row (HPTV). Various methods were used to evaluate the influence of clocking on the aeroperformance (efficiency) and the aerodynamics (pressure loading) of the LPTV, including time-resolved and time-averaged measurements. A change in overall efficiency of approximately 2–3% due to clocking effects is demonstrated and could be observed using a variety of independent methods. Maximum efficiency is obtained when the time-average surface pressures are highest on the LPTV and the time-resolved surface pressure (both in the time domain and frequency domain) show the least amount of variation. The overall effect is obtained by integrating over the entire airfoil, as the three-dimensional effects on the LPTV surface are significant. This experimental data set validates several computational research efforts that suggested wake migration is the primary reason for the perceived effectiveness of vane clocking. The suggestion that wake migration is the dominate mechanism in generating the clocking effect is also consistent with anecdotal evidence that fully cooled engine rigs do not see a great deal of clocking effect. This is consistent since the additional disturbances induced by the cooling flows and/or the combustor make it extremely difficult to find an alignment for the LPTV given the strong 3D nature of modern High-Pressure Turbine flows.Copyright © 2004 by ASME