Daniel Dorney - Academia.edu (original) (raw)
Papers by Daniel Dorney
39th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit, 2003
During a post-flight inspection of the liquid hydrogen feed lines leading the Space Shuttle main ... more During a post-flight inspection of the liquid hydrogen feed lines leading the Space Shuttle main engines cracks were discover in slots on a flow liner just upstream of the low pressure fuel pump inducer. Numerical simulations have been performed for the feed line, the flow liner (including the slots and backing cavity) and the inducer. The predicted results have been compared with experimental data taken during hot-fire tests at NASA Stennis Space Center.
40th AIAA Aerospace Sciences Meeting & Exhibit, 2002
INTRODUCTION Modern high-work turbines can be compact, transonic, supersonic, counter rotating, a... more INTRODUCTION Modern high-work turbines can be compact, transonic, supersonic, counter rotating, and can use a dense drive gas. The vast majority of modern rocket turbine designs fall into these categories. These turbines are often characterized by large amounts of flow unsteadiness. The flow unsteadiness can have a major impact on turbine performance and durability.
35th Joint Propulsion Conference and Exhibit, 1999
Accurate unsteady temperature distributions within jet engine turbine blades are difficult to pre... more Accurate unsteady temperature distributions within jet engine turbine blades are difficult to predict, so large safety margins must be employed to ensure that hot spots and thermal cycling do not damage the blades. Improved temperature predictions could lead toward higher thermal efficiencies and longer blade life.
32nd Joint Propulsion Conference and Exhibit, 1996
Et Streak Higratlot and #dm. I£Effects on the Beat Transfar in Contract No. NOO1O-8-C-0677 notor/... more Et Streak Higratlot and #dm. I£Effects on the Beat Transfar in Contract No. NOO1O-8-C-0677 notor/Stator Interactint flows-Rport 'I D. J. Dorney, V4 L. Davis, D.. B 4s 7. WOMWG ORGANIZATION NADM(I) £AN0 AMORES($)-8. IMRORMING ORGANIZATION RIK T NUMSER United Zech alo-tes Aese-ch Center 413. Silver Lane, IS 129-20 ;ast Hartford, CT 06108 irm 91-29 V. S ?W4O7VEjMO NGd A4;ENCty NAME(AND ADOJ%9$(1ES) I0-S.OSPNJ~4T*N 0££1 o Ees az-b/li&val J3.r b" ~ml~ Cam am4AGE NCY REPORT NUM INR Of fles of Nlavel Research/lWsval Air SYstems Cmand Departmnt of One OW"
Volume 1: Aircraft Engine; Marine; Turbomachinery; Microturbines and Small Turbomachinery, 2001
ABSTRACT Multi-stage turbines have inherently unsteady flow fields because of relative motion bet... more ABSTRACT Multi-stage turbines have inherently unsteady flow fields because of relative motion between rotating and stationary airfoil rows. This relative motion leads to viscous and inviscid interactions between blade rows. As the number of stages increases in a turbomachine, the buildup of convected wakes can lead to progressively more complex wake/wake and wake/airfoil interactions. Variations in the relative circumferential positions of airfoils in adjacent rotating or non-rotating blade rows can alter these interactions, leading to different time-averaged losses and stage efficiencies. In addition, interaction between blade rows can intensify with increasing Mach number due to potential effects.It has been shown in previous studies, both experimental and computational, that airfoil clocking can be used to improve the efficiency and reduce the unsteadiness in multiple-stage axial turbomachines with equal blade counts. While previous investigations have for the most part focused on two-stage turbines, the goal of the current research is to evaluate the effects of clocking an embedded stage within a larger turbine system. Quasi-three-dimensional simulations of airfoil clocking have been performed for a four-stage industrial turbine. Time-averaged and unsteady data (including performance quantities) are presented. The results show a 0.5% efficiency variation in the stage where the vanes were clocked, and smaller efficiency variations in the upstream and downstream stages. The overall efficiency of the turbine system varies with the efficiency of the clocked stage, although by a smaller amount.
Turbomachines for propulsion applications operate with many different working fluids and flow con... more Turbomachines for propulsion applications operate with many different working fluids and flow conditions. The flow may be incompressible, such as in the liquid hydrogen pump in a rocket engine, or supersonic, such as in the turbine which may drive the hydrogen pump. Separate codes have traditionally been used for incompressible and compressible flow solvers. The General Equation Set (GES) method can be used to solve both incompressible and compressible flows, and it is not restricted to perfect gases, as are many compressible-flow turbomachinery solvers. An unsteady GES turbomachinery flow solver has been developed and applied to both air and water flows through turbines. It has been shown to be an excellent alternative to maintaining two separate codes.
32nd Joint Propulsion Conference and Exhibit, 1996
International Journal of Turbo and Jet Engines, 1999
Experimental and computational data have shown that the flow exiting gas-turbine combustors can c... more Experimental and computational data have shown that the flow exiting gas-turbine combustors can contain large circumferential and radial temperature non-uniformities. The temperature non-uniformities, or hot streaks, can have a significant impact on the performance and durability of first-stage turbine airfoils. This paper contains a survey of the hot streak experiments and simulations that have been performed during the last two decades, and the impact they have had on the design of high-pressure turbine stages.
International Journal of Turbo and Jet Engines, 1997
32nd Joint Propulsion Conference and Exhibit, 1996
35th Joint Propulsion Conference and Exhibit, 1999
Experimental data have shown that combustor temperature non-uniformities can lead to the excessiv... more Experimental data have shown that combustor temperature non-uniformities can lead to the excessive heating of first-stage rotor blades in turbines. This heating of the rotor blades can lead to thermal fatigue and degrade turbine performance. The results of recent studies have shown that variations in the circumferential location, or clocking, of the first-stage vane airfoils can be used to minimize the adverse effects of the hot streaks due to the hot fluid mixing with the cooler fluid contained in the vane wake. Less effort has been put into determining the effects of the hot streak/airfoil count ratio on the heating patterns of turbine airfoils. In the present investigation, threedimensional unsteady Navier-Stokes simulations have been performed for a single-stage high-pressure turbine geometry operating in high subsonic flow. Simulations were initially performed without hot streaks to compare with the experimental data. The ratio of the number of hot streaks to the number of vanes and rotors was then varied. The predicted results demonstrate a complex interaction between the hot streak *Associate Professor, Senior Member AIAA t Senior Analyst, Senior Member AIAA 1 Assistant Professor, Member AIAA Copyright 01999 by Daniel Dorney, Douglas Sondak and Paul Cizmas. Published by the American Institute of Aeronautics and Astronautics, Inc. with permission. and the secondary flows in the rotor.
39th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit, 2003
Numerical simulations have been completed for a variety of designs for a 90 deg elbow duct. The o... more Numerical simulations have been completed for a variety of designs for a 90 deg elbow duct. The objective is to identify a design that minimizes the dynamic load entering a LOX turbopump located at the elbow exit. Designs simulated to date indicate that simpler duct geometries result in lower losses. Benchmark simulations have verified that the compressible flow code used in this study is applicable to these incompressible flow simulations.
33rd AIAA Fluid Dynamics Conference and Exhibit, 2003
In order to mitigate the risk of rocket propulsion development, efficient, accurate, detailed flu... more In order to mitigate the risk of rocket propulsion development, efficient, accurate, detailed fluid dynamics analysis of the turbomachinery is necessary. This analysis is used for component development, design parametrics, performance prediction, and environment definition. To support this requirement, a task was developed at NASA/Marshall Space Flight Center (MSFC) to improve turbine aerodynamic performance through the application of advanced design and analysis tools. There are four major objectives of this task: 1) to develop, enhance, and integrate advanced turbine aerodynamic design and analysis tools; 2) to develop the methodology for application of the analytical techniques; 3) to demonstrate the benefits of the advanced turbine design procedure through its application to a relevant turbine design point; and 4) to verify the optimized design and analysis with testing. The turbine chosen on which to demonstrate the procedure was a supersonic design suitable for a reusable launch vehicle (RLV). The hot gas path and blading were redesigned to obtain an increased efficiency. The redesign of the turbine was conducted with a consideration of system requirements, realizing that a highly efficient turbine that, for example, significantly increases engine weight, is of limited benefit. Both preliminary and detailed designs were considered. To generate an improved design, onedimensional (1D) design and analysis tools, computational fluid dynamics (CFD), response surface methodology (RSM), and neural nets (NN) were used. The goal of the demonstration was to increase the total-tostatic efficiency, ηt-s, of the turbine by eight points over the baseline design. The predicted ηt-s of the optimized design was 11 points higher than the baseline. A subscale test article of the final turbine geometry was designed, manufactured, and tested in air. Extensive onand off- design point performance data, steady-state data, and unsteady blade loading data were collected during testing. Although analysis of the data is in progress, initial results show that the goals of the TPO program have been met, showing a measured ηt-s increase of 9 points at design conditions.
Volume 8: Heat Transfer, Fluid Flows, and Thermal Systems, Parts A and B, 2007
In this study, a 3-D, unsteady, Reynolds-averaged Navier-Stokes (RANS) CFD code coupled to an aco... more In this study, a 3-D, unsteady, Reynolds-averaged Navier-Stokes (RANS) CFD code coupled to an acoustic calculation is used to predict the contribution of the exit guide vanes to tonal fan noise downstream. The configuration investigated is that corresponding to the NASA Source Diagnostic Test (SDT) 22-in fan rig. One configuration from the SDT matrix is considered here: the approach condition, and outlet guide vane count designed for cutoff of the blade passage frequency. In this chosen configuration, there are 22 rotor blades and 54 stator blades. The stators are located 2.5 tip chords downstream of the rotor trailing edge. The RANS computations are used to obtain the spectra of the unsteady surface pressure on the exit guide vanes. The surface pressure at the blade passage frequency and its second harmonic are then integrated together with the Green's function for an annular duct to obtain the pressure at locations in the duct. Comparison of the computed sound power level at the exhaust plane with experiment show good agreement at the cut-on circumferential mode. The results from this investigation validate the use of the CFD code along with the acoustic model for downstream * Address all correspondence to this author. fan noise predictions. This validation enables future investigations such as the effect of duct variation on the exhaust tonal power level and the validity of using this method for predicting broadband noise levels. NOMENCLATURE β = √ 1 − M 2 compressibility parameter ω radial frequency of disturbance a outer radius of annulus c chordlength c 0 mean speed of sound h inner radius of annulus I acoustic intensity g gust amplitude, 2D benchmark simulation G Green's function J n ,Y n Bessel functions of order n k = ω/c 0 acoustic wave number k 1 , k 2 nondimensional wave numbers of 2D gust K nm eigenfrequencies of propagation M Mach number 1 Copyright c 2007 by ASME p pressure P acoustic power q, s integers, multipliers of B and V r h , r t , r radial location of rotor hub, tip, strip u acoustic velocity in the axial direction (x, y, z), (r, θ, z) point in space x 0 = (r 0 , θ 0 , z 0) source locations
33rd Aerospace Sciences Meeting and Exhibit, 1995
41st Aerospace Sciences Meeting and Exhibit, 2003
The drive towards high-work turbines has led to designs which can be compact, transonic, superson... more The drive towards high-work turbines has led to designs which can be compact, transonic, supersonic, counter rotating, or use a dense drive gas. These aggressive designs can lead to strong unsteady secondary flows and flow separation. The amplitude and extent of these unsteady flow phenomena can be amplified at off-design operating conditions. Pre-test off-design predictions have been performed for a new two-stage supersonic turbine design that is currently being tested in air. The simulations were performed using a three-dimensional unsteady Navier-Stokes analysis, and the predicted results have been compared with solutions from a validated meanline analysis.
39th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit, 2003
ABSTRACT
39th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit, 2003
During a post-flight inspection of the liquid hydrogen feed lines leading the Space Shuttle main ... more During a post-flight inspection of the liquid hydrogen feed lines leading the Space Shuttle main engines cracks were discover in slots on a flow liner just upstream of the low pressure fuel pump inducer. Numerical simulations have been performed for the feed line, the flow liner (including the slots and backing cavity) and the inducer. The predicted results have been compared with experimental data taken during hot-fire tests at NASA Stennis Space Center.
40th AIAA Aerospace Sciences Meeting & Exhibit, 2002
INTRODUCTION Modern high-work turbines can be compact, transonic, supersonic, counter rotating, a... more INTRODUCTION Modern high-work turbines can be compact, transonic, supersonic, counter rotating, and can use a dense drive gas. The vast majority of modern rocket turbine designs fall into these categories. These turbines are often characterized by large amounts of flow unsteadiness. The flow unsteadiness can have a major impact on turbine performance and durability.
35th Joint Propulsion Conference and Exhibit, 1999
Accurate unsteady temperature distributions within jet engine turbine blades are difficult to pre... more Accurate unsteady temperature distributions within jet engine turbine blades are difficult to predict, so large safety margins must be employed to ensure that hot spots and thermal cycling do not damage the blades. Improved temperature predictions could lead toward higher thermal efficiencies and longer blade life.
32nd Joint Propulsion Conference and Exhibit, 1996
Et Streak Higratlot and #dm. I£Effects on the Beat Transfar in Contract No. NOO1O-8-C-0677 notor/... more Et Streak Higratlot and #dm. I£Effects on the Beat Transfar in Contract No. NOO1O-8-C-0677 notor/Stator Interactint flows-Rport 'I D. J. Dorney, V4 L. Davis, D.. B 4s 7. WOMWG ORGANIZATION NADM(I) £AN0 AMORES($)-8. IMRORMING ORGANIZATION RIK T NUMSER United Zech alo-tes Aese-ch Center 413. Silver Lane, IS 129-20 ;ast Hartford, CT 06108 irm 91-29 V. S ?W4O7VEjMO NGd A4;ENCty NAME(AND ADOJ%9$(1ES) I0-S.OSPNJ~4T*N 0££1 o Ees az-b/li&val J3.r b" ~ml~ Cam am4AGE NCY REPORT NUM INR Of fles of Nlavel Research/lWsval Air SYstems Cmand Departmnt of One OW"
Volume 1: Aircraft Engine; Marine; Turbomachinery; Microturbines and Small Turbomachinery, 2001
ABSTRACT Multi-stage turbines have inherently unsteady flow fields because of relative motion bet... more ABSTRACT Multi-stage turbines have inherently unsteady flow fields because of relative motion between rotating and stationary airfoil rows. This relative motion leads to viscous and inviscid interactions between blade rows. As the number of stages increases in a turbomachine, the buildup of convected wakes can lead to progressively more complex wake/wake and wake/airfoil interactions. Variations in the relative circumferential positions of airfoils in adjacent rotating or non-rotating blade rows can alter these interactions, leading to different time-averaged losses and stage efficiencies. In addition, interaction between blade rows can intensify with increasing Mach number due to potential effects.It has been shown in previous studies, both experimental and computational, that airfoil clocking can be used to improve the efficiency and reduce the unsteadiness in multiple-stage axial turbomachines with equal blade counts. While previous investigations have for the most part focused on two-stage turbines, the goal of the current research is to evaluate the effects of clocking an embedded stage within a larger turbine system. Quasi-three-dimensional simulations of airfoil clocking have been performed for a four-stage industrial turbine. Time-averaged and unsteady data (including performance quantities) are presented. The results show a 0.5% efficiency variation in the stage where the vanes were clocked, and smaller efficiency variations in the upstream and downstream stages. The overall efficiency of the turbine system varies with the efficiency of the clocked stage, although by a smaller amount.
Turbomachines for propulsion applications operate with many different working fluids and flow con... more Turbomachines for propulsion applications operate with many different working fluids and flow conditions. The flow may be incompressible, such as in the liquid hydrogen pump in a rocket engine, or supersonic, such as in the turbine which may drive the hydrogen pump. Separate codes have traditionally been used for incompressible and compressible flow solvers. The General Equation Set (GES) method can be used to solve both incompressible and compressible flows, and it is not restricted to perfect gases, as are many compressible-flow turbomachinery solvers. An unsteady GES turbomachinery flow solver has been developed and applied to both air and water flows through turbines. It has been shown to be an excellent alternative to maintaining two separate codes.
32nd Joint Propulsion Conference and Exhibit, 1996
International Journal of Turbo and Jet Engines, 1999
Experimental and computational data have shown that the flow exiting gas-turbine combustors can c... more Experimental and computational data have shown that the flow exiting gas-turbine combustors can contain large circumferential and radial temperature non-uniformities. The temperature non-uniformities, or hot streaks, can have a significant impact on the performance and durability of first-stage turbine airfoils. This paper contains a survey of the hot streak experiments and simulations that have been performed during the last two decades, and the impact they have had on the design of high-pressure turbine stages.
International Journal of Turbo and Jet Engines, 1997
32nd Joint Propulsion Conference and Exhibit, 1996
35th Joint Propulsion Conference and Exhibit, 1999
Experimental data have shown that combustor temperature non-uniformities can lead to the excessiv... more Experimental data have shown that combustor temperature non-uniformities can lead to the excessive heating of first-stage rotor blades in turbines. This heating of the rotor blades can lead to thermal fatigue and degrade turbine performance. The results of recent studies have shown that variations in the circumferential location, or clocking, of the first-stage vane airfoils can be used to minimize the adverse effects of the hot streaks due to the hot fluid mixing with the cooler fluid contained in the vane wake. Less effort has been put into determining the effects of the hot streak/airfoil count ratio on the heating patterns of turbine airfoils. In the present investigation, threedimensional unsteady Navier-Stokes simulations have been performed for a single-stage high-pressure turbine geometry operating in high subsonic flow. Simulations were initially performed without hot streaks to compare with the experimental data. The ratio of the number of hot streaks to the number of vanes and rotors was then varied. The predicted results demonstrate a complex interaction between the hot streak *Associate Professor, Senior Member AIAA t Senior Analyst, Senior Member AIAA 1 Assistant Professor, Member AIAA Copyright 01999 by Daniel Dorney, Douglas Sondak and Paul Cizmas. Published by the American Institute of Aeronautics and Astronautics, Inc. with permission. and the secondary flows in the rotor.
39th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit, 2003
Numerical simulations have been completed for a variety of designs for a 90 deg elbow duct. The o... more Numerical simulations have been completed for a variety of designs for a 90 deg elbow duct. The objective is to identify a design that minimizes the dynamic load entering a LOX turbopump located at the elbow exit. Designs simulated to date indicate that simpler duct geometries result in lower losses. Benchmark simulations have verified that the compressible flow code used in this study is applicable to these incompressible flow simulations.
33rd AIAA Fluid Dynamics Conference and Exhibit, 2003
In order to mitigate the risk of rocket propulsion development, efficient, accurate, detailed flu... more In order to mitigate the risk of rocket propulsion development, efficient, accurate, detailed fluid dynamics analysis of the turbomachinery is necessary. This analysis is used for component development, design parametrics, performance prediction, and environment definition. To support this requirement, a task was developed at NASA/Marshall Space Flight Center (MSFC) to improve turbine aerodynamic performance through the application of advanced design and analysis tools. There are four major objectives of this task: 1) to develop, enhance, and integrate advanced turbine aerodynamic design and analysis tools; 2) to develop the methodology for application of the analytical techniques; 3) to demonstrate the benefits of the advanced turbine design procedure through its application to a relevant turbine design point; and 4) to verify the optimized design and analysis with testing. The turbine chosen on which to demonstrate the procedure was a supersonic design suitable for a reusable launch vehicle (RLV). The hot gas path and blading were redesigned to obtain an increased efficiency. The redesign of the turbine was conducted with a consideration of system requirements, realizing that a highly efficient turbine that, for example, significantly increases engine weight, is of limited benefit. Both preliminary and detailed designs were considered. To generate an improved design, onedimensional (1D) design and analysis tools, computational fluid dynamics (CFD), response surface methodology (RSM), and neural nets (NN) were used. The goal of the demonstration was to increase the total-tostatic efficiency, ηt-s, of the turbine by eight points over the baseline design. The predicted ηt-s of the optimized design was 11 points higher than the baseline. A subscale test article of the final turbine geometry was designed, manufactured, and tested in air. Extensive onand off- design point performance data, steady-state data, and unsteady blade loading data were collected during testing. Although analysis of the data is in progress, initial results show that the goals of the TPO program have been met, showing a measured ηt-s increase of 9 points at design conditions.
Volume 8: Heat Transfer, Fluid Flows, and Thermal Systems, Parts A and B, 2007
In this study, a 3-D, unsteady, Reynolds-averaged Navier-Stokes (RANS) CFD code coupled to an aco... more In this study, a 3-D, unsteady, Reynolds-averaged Navier-Stokes (RANS) CFD code coupled to an acoustic calculation is used to predict the contribution of the exit guide vanes to tonal fan noise downstream. The configuration investigated is that corresponding to the NASA Source Diagnostic Test (SDT) 22-in fan rig. One configuration from the SDT matrix is considered here: the approach condition, and outlet guide vane count designed for cutoff of the blade passage frequency. In this chosen configuration, there are 22 rotor blades and 54 stator blades. The stators are located 2.5 tip chords downstream of the rotor trailing edge. The RANS computations are used to obtain the spectra of the unsteady surface pressure on the exit guide vanes. The surface pressure at the blade passage frequency and its second harmonic are then integrated together with the Green's function for an annular duct to obtain the pressure at locations in the duct. Comparison of the computed sound power level at the exhaust plane with experiment show good agreement at the cut-on circumferential mode. The results from this investigation validate the use of the CFD code along with the acoustic model for downstream * Address all correspondence to this author. fan noise predictions. This validation enables future investigations such as the effect of duct variation on the exhaust tonal power level and the validity of using this method for predicting broadband noise levels. NOMENCLATURE β = √ 1 − M 2 compressibility parameter ω radial frequency of disturbance a outer radius of annulus c chordlength c 0 mean speed of sound h inner radius of annulus I acoustic intensity g gust amplitude, 2D benchmark simulation G Green's function J n ,Y n Bessel functions of order n k = ω/c 0 acoustic wave number k 1 , k 2 nondimensional wave numbers of 2D gust K nm eigenfrequencies of propagation M Mach number 1 Copyright c 2007 by ASME p pressure P acoustic power q, s integers, multipliers of B and V r h , r t , r radial location of rotor hub, tip, strip u acoustic velocity in the axial direction (x, y, z), (r, θ, z) point in space x 0 = (r 0 , θ 0 , z 0) source locations
33rd Aerospace Sciences Meeting and Exhibit, 1995
41st Aerospace Sciences Meeting and Exhibit, 2003
The drive towards high-work turbines has led to designs which can be compact, transonic, superson... more The drive towards high-work turbines has led to designs which can be compact, transonic, supersonic, counter rotating, or use a dense drive gas. These aggressive designs can lead to strong unsteady secondary flows and flow separation. The amplitude and extent of these unsteady flow phenomena can be amplified at off-design operating conditions. Pre-test off-design predictions have been performed for a new two-stage supersonic turbine design that is currently being tested in air. The simulations were performed using a three-dimensional unsteady Navier-Stokes analysis, and the predicted results have been compared with solutions from a validated meanline analysis.
39th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit, 2003
ABSTRACT