Influence of Backward- and Forward-Facing Steps on the Flow Through a Turning Mid Turbine Frame

2017 ◽  
Vol 139 (12) ◽  
Author(s):  
Sabine Bauinger ◽  
Emil Goettlich ◽  
Franz Heitmeir ◽  
Franz Malzacher
Keyword(s):  
High Pressure ◽  
Total Pressure ◽  
Test Rig ◽  
Test Setup ◽  
Aero Engine ◽  
Total Temperature ◽  
Flow Through ◽  
Run Up ◽  
Compact Design ◽  
Probe Measurements

For this work, reality effects, more precisely backward-facing steps (BFSs) and forward-facing steps (FFSs), and their influence on the flow through a two-stage two-spool turbine rig under engine-relevant conditions were experimentally investigated. The test rig consists of an high pressure (HP) and an low pressure (LP) stage, with the two rotors rotating in opposite direction with two different rotational speeds. An S-shaped transition duct, which is equipped with turning struts (so-called turning mid turbine frame (TMTF)) and making therefore a LP stator redundant, connects both stages and leads the flow from a smaller to a larger diameter. This test setup allows the investigation of a TMTF deformation, which occurs in a real aero-engine due to non-uniform warming of the duct during operation—especially during run up—and causes BFSs and FFSs in the flow path. This happens for nonsegmented ducts, which are predominantly part of smaller engines. In the case of the test rig, steps were not generated by varying temperature but by shifting the TMTF in horizontal direction while the rotor and its casing were kept in the same position. In this way, both BFSs and FFSs between duct endwalls and rotor casing could be created. In order to avoid steps further downstream of the interface between HP rotor and TMTF, the complete aft rig was moved laterally too. In this case, the aft rig incorporates among others the LP rotor, the LP rotor casing, and the deswirler downstream of the LP stage. In order to catch the influence of the steps on the whole flow field, 360 deg rake traverses were performed downstream of the HP rotor, downstream of the duct, and downstream of the LP rotor with newly designed, laser-sintered combi-rakes for the measurement of total pressure and total temperature. Only the compact design of the rakes, which can be easily realized by additive manufacturing, makes the aforementioned 360 deg traverses in this test rig possible and allows a number of radial measurements positions, which is comparable to those of a five-hole probe. To get a more detailed information about the flow, also five-hole probe measurements were carried out in three measurement planes and compared to the results of the combi-rakes.

Influence of Backward and Forward Facing Steps on the Flow Through a Turning Mid Turbine Frame

2017 ◽  
Author(s):  
Sabine Bauinger ◽  
Franz Malzacher ◽  
Emil Goettlich ◽  
Franz Heitmeir
Keyword(s):  
Additive Manufacturing ◽  
Total Pressure ◽  
Test Rig ◽  
Test Setup ◽  
Aero Engine ◽  
Total Temperature ◽  
Flow Through ◽  
Run Up ◽  
Compact Design ◽  
Probe Measurements

For this work, reality effects, more precisely backward and forward facing steps, and their influence on the flow through a two-stage two-spool turbine rig under engine-relevant conditions were experimentally investigated. The test rig consists of a HP and a LP stage, with the two rotors rotating in opposite direction with two different rotational speeds. An S-shaped transition duct, which is equipped with turning struts (so-called turning mid turbine frame or TMTF) and making therefore a LP stator redundant, connects both stages and leads the flow from a smaller to a larger diameter. This test setup allows the investigation of a TMTF deformation, which occurs in a real aero-engine due to non-uniform warming of the duct during operation — especially during run up — and causes backward and forward facing steps in the flow path. This happens for non-segmented ducts, which are predominantly part of smaller engines. In the case of the test rig, steps were not generated by varying temperature but by shifting the TMTF in horizontal direction while the rotor and its casing were kept in the same position. In this way, both backward and forward facing steps between duct endwalls and rotor casing could be created. In order to avoid steps further downstream of the interface between HP rotor and TMTF, the complete aft rig was moved laterally too. In this case, the aft rig incorporates amongst others the LP rotor, the LP rotor casing and the deswirler downstream of the LP stage. In order to catch the influence of the steps on the whole flow field, 360 deg rake traverses were performed downstream of the HP rotor, downstream of the duct and downstream of the LP rotor with newly designed, laser-sintered Combi-Rakes for the measurement of total pressure and total temperature. Only the compact design of the rakes, which can be easily realised by additive manufacturing, makes the aforementioned 360 deg traverses in this test rig possible and allows a number of radial measurements positions, which is comparable to those of a five hole probe. To get a more detailed information about the flow, also five hole probe measurements were carried out in three measurement planes and compared to the results of the Combi-Rakes.

Investigation of Combustor-Turbine-Interaction in a Rotating Cooled Transonic High-Pressure Turbine Test Rig: Part 2 — Numerical Modelling and Simulation

2019 ◽  
Author(s):  
Simon Gövert ◽  
Federica Ferraro ◽  
Alexander Krumme ◽  
Clemens Buske ◽  
Marc Tegeler ◽  
...  
Keyword(s):  
High Pressure ◽  
Flame Stabilization ◽  
Test Facility ◽  
Test Rig ◽  
High Pressure Turbine ◽  
Lean Burn ◽  
Turbine Inlet ◽  
Measurement Results ◽  
Aero Engine ◽  
Inlet Conditions

Abstract Reducing the uncertainties in the prediction of turbine inlet conditions is a crucial aspect to improve aero engine designs and further increase engine efficiencies. To meet constantly stricter emission regulations, lean burn combustion could play a key role for future engine designs. However, these combustion systems are characterized by significant swirl for flame stabilization and reduced cooling air mass flows. As a result, substantial spatial and transient variations of the turbine inlet conditions are encountered. To investigate the effect of the combustor on the high pressure turbine, a rotating cooled transonic high-pressure configuration has been designed and investigated experimentally at the DLR turbine test facility ‘NG-Turb’ in Göttingen, Germany. It is a rotating full annular 1.5 stage turbine configuration which is coupled to a combustor simulator. The combustor simulator is designed to create turbine inlet conditions which are hydrodynamically representative for a lean-burn aero engine. A detailed description of the test rig and its instrumentation as well as a discussion of the measurement results is presented in part I of this paper. Part II focuses on numerical modeling of the test rig to further extend the understanding of the measurement results. Integrated simulations of the configuration including combustor simulator and nozzle guide vanes are performed for leading edge and passage clocking position and the effect on the hot streak migration is discussed. The simulation and experimental results at the combustor-turbine interface are compared showing a good overall agreement. The relevant flow features are correctly predicted in the simulations, proving the suitability of the numerical model for application to integrated combustor-turbine interaction analysis.

Investigation of Combustor-Turbine-Interaction in a Rotating Cooled Transonic High-Pressure Turbine Test Rig: Part 1 — Experimental Results

2019 ◽  
Author(s):  
Alexander Krumme ◽  
Clemens Buske ◽  
Johannes R. Bachner ◽  
Jerrit Dähnert ◽  
Marc Tegeler ◽  
...  
Keyword(s):  
Boundary Condition ◽  
High Pressure ◽  
Flow Field ◽  
Flow Structures ◽  
Test Rig ◽  
High Pressure Turbine ◽  
Set Up ◽  
German Aerospace ◽  
Interaction Research ◽  
Probe Measurements

Abstract Within the scope of European Commission FP7 project FACTOR, dedicated to combustor-turbine-interaction research, a clean-sheet design of a rotating turbine test rig featuring a non-reacting combustor simulator was created and built among the partners. German Aerospace Center DLR provided the operational facility NG-Turb to which the rig was adapted and was responsible for global rig integration and operation, also including aerodynamic probe measurements of the flow field. The rig and experimental set-up is described and post-processed results from probe traverses in several measurement planes are presented and discussed. Special attention is paid to the comparison and influence of two combustor-NGV clocking positions on the periodic turbine flow field, made possible by rig adaptation during the campaign. The strongly distorted and nonuniform turbine inlet flow created by the combustor simulator proved challenging for the probe measurements, but at the same time set a realistic boundary condition enabling the analysis of ‘CTI’ by flow structures migrating through the blade rows.

Effects of axial length and integrated design on the aggressive intermediate turbine duct

2018 ◽  
Vol 233 (4) ◽  
pp. 443-456 ◽  
Author(s):  
Qingzong Xu ◽  
Pei Wang ◽  
Qiang Du ◽  
Jun Liu ◽  
Guang Liu
Keyword(s):  
Boundary Layer ◽  
High Pressure ◽  
Secondary Flow ◽  
Axial Length ◽  
Pressure Loss ◽  
Total Pressure ◽  
Guide Vane ◽  
Three Dimensional ◽  
Intermediate Turbine Duct ◽  
Aero Engine

With the increasing demand of high bypass ratio and thrust-to-weight ratio in civil aero-engine, the intermediate turbine duct between the high pressure and low pressure turbines of a modern gas turbine tends to shorter axial length, larger outlet-to-inlet area ratio and high pressure-to-low pressure radial offset. This paper experimentally and numerically investigated the three-dimensional flow characteristics of traditional (ITD1) and aggressive intermediate turbine duct (ITD2) at low Reynolds number. The baseline case of ITD1 is representative of a traditional intermediate turbine duct of aero-engine design with non-dimensional length of L/dR = 2.79 and middle angle of 20.12°. The detailed flow fields inside ITD1 and flow visualization were measured. Results showed the migration of boundary layer and a pair of counter-rotating vortexes were formed due to the radial migration of low momentum fluid. With the decreasing axial length of intermediate turbine duct, the radial and streamwise reverse pressure gradient in aggressive intermediate turbine duct (ITD2) were increased resulting in severe three-dimensional separation of boundary layer near casing surface and higher total pressure loss. The secondary flow and separation of boundary layer near the endwall were deeply analyzed to figure out the main source of high total pressure loss in the aggressive intermediate turbine duct (ITD2). Based on that, employing wide-chord guide vane to substitute “strut + guide vane”, this paper designed the super-aggressive intermediate turbine duct and realized the suppression of the three-dimensional separation and secondary flow.

Effects of Combustor Exit Profiles on High Pressure Turbine Vane Aerodynamics and Heat Transfer

2006 ◽  
Author(s):  
M. D. Barringer ◽  
K. A. Thole ◽  
M. D. Polanka
Keyword(s):  
Heat Transfer ◽  
High Pressure ◽  
Total Pressure ◽  
Temperature Profiles ◽  
High Pressure Turbine ◽  
Pressure Profiles ◽  
Turbine Vane ◽  
Baseline Test ◽  
Total Temperature ◽  
Air Force Research Laboratory

The goal of this work was to investigate the effects of different profiles representative of those exiting aero-engine combustors on high pressure turbine vane aerodynamics and heat transfer. The various profiles were produced using the non-reacting, inlet profile generator in the Turbine Research Facility (TRF) located at the Air Force Research Laboratory (AFRL). This paper reports how the pressure loading and heat transfer along the vane surface is affected by different turbine inlet pressure and temperature profiles at several different span locations. The results indicate that the different inlet total pressure profiles affected the aerodynamic loading by as much as 10%. The results also reveal that the combination of different total pressure and total temperature profiles significantly affected the vane heat transfer for a baseline test with relatively uniform inlet total pressure and total temperature profiles. Near the ID endwall, the baseline heat transfer was reduced 30 to 40% over the majority of the vane surface. Near the OD endwall, it was found that certain inlet profiles could increase the baseline heat transfer by 20 to 30%, while other profiles resulted in a decrease of the baseline heat transfer by 30 to 40%.

Effects of Combustor Exit Profiles on Vane Aerodynamic Loading and Heat Transfer in a High Pressure Turbine

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
M. D. Barringer ◽  
K. A. Thole ◽  
M. D. Polanka
Keyword(s):  
Heat Transfer ◽  
High Pressure ◽  
Total Pressure ◽  
Temperature Profiles ◽  
High Pressure Turbine ◽  
Local Flow ◽  
Aerodynamic Loading ◽  
Turbine Inlet ◽  
Pressure Profiles ◽  
Total Temperature

The flow and thermal fields exiting gas turbine combustors dictate the overall performance of the downstream turbine. The goal of this work was to investigate the effects of engine representative combustor exit profiles on high pressure turbine vane aerodynamics and heat transfer. The various profiles were produced using a nonreacting turbine inlet profile generator in the Turbine Research Facility (TRF) located at the Air Force Research Laboratory (AFRL). This paper reports how the pressure loading and heat transfer along the vane surface was affected by different turbine inlet pressure and temperature profiles at different span locations. The results indicate that the inlet total pressure profiles affected the aerodynamic loading by as much as 10%. The results also reveal that the combination of different total pressure and total temperature profiles significantly affected the vane heat transfer relative to a baseline test with uniform inlet total pressure and total temperature. Near the inner diameter endwall, the baseline heat transfer was reduced 30–40% over the majority of the vane surface. Near the outer dimeter endwall, it was found that certain inlet profiles could increase the baseline heat transfer by 10–20%, while other profiles resulted in a decrease in the baseline heat transfer by 25–35%. This study also shows the importance of knowing an accurate prediction of the local flow driving temperature when determining vane surface heat transfer.

Comparison of a State of the Art and a High Stage Loading Rotor

2014 ◽  
Author(s):  
Thorsten Selic ◽  
Davide Lengani ◽  
Florian Schönleitner ◽  
Andreas Marn ◽  
Dominik Broszat
Keyword(s):  
Total Pressure ◽  
Pressure Ratio ◽  
Measurement Data ◽  
Flow Fields ◽  
Pressure Probe ◽  
Model Parameters ◽  
Test Rig ◽  
Blade Loading ◽  
Aero Engine ◽  
Highly Loaded

This paper presents measurement results of a 1½ stage LPT test rig at Graz University of Technology incorporating two different rotor geometries: one with a regular blade loading and a second rotor with a highly loaded blade geometry. The test rig was designed in cooperation with MTU Aero Engines and represents the last 1.5 stages of a commercial aero engine. Considerable efforts were put on the adjustment of all relevant model parameters (Mach number, blade count ratio, airfoil aspect ratio, blade loading, etc.) to reproduce the full scale LPT situation. The rig diameter is approximately half of that of a commercial aero engine LPT. The number of blades and vanes for the two investigated stages as well as the pressure ratio and power output are identical, resulting in a decrease in rotational speed of the HSL rotor. Measurement data from a fast response pressure probe (FRAPP) is used to compare the flow fields of the two different stages. The effect of the different stage designs can be seen when comparing the exit flow fields. The highly loaded stage shows a more pronounced tip leakage vortex compared to the datum stage. The highly loaded stage shows wider wakes with a lower total pressure deficit. The fluctuations of total pressure within the flow field are directly related to the upstream wake. If the measurement position is located within a stator wake, the fluctuations are significantly smaller than out of the wake.

INVESTIGATION OF THE TIME OF GAS FLOW THROUGH A HOLE IN LONG PIPELINES UNDER HIGH PRESSURE

2020 ◽  
Vol 58 (1) ◽  
pp. 30-43
Author(s):  
N.D. Yakimov ◽  
◽  
A.I. Khafizova ◽  
N.D. Chichirova ◽  
O.S. Dmitrieva ◽  
...  
Keyword(s):  
High Pressure ◽  
Gas Flow ◽  
Flow Through

scholarly journals Initial study on removing cellular residues from hydrostatic high-pressure treated allogeneic tissue using ultrasound

2020 ◽  
Vol 6 (3) ◽  
pp. 176-179
Author(s):  
Christoph Drobek ◽  
Janine Waletzko ◽  
Michael Dau ◽  
Bernhard Frerich ◽  
Volker Weißmann ◽  
...  
Keyword(s):  
High Pressure ◽  
Structural Properties ◽  
Dna Content ◽  
Bone Allograft ◽  
Initial Study ◽  
Microbiological Contamination ◽  
Test Setup ◽  
Allograft Tissue ◽  
Bone Allografts ◽  
Content Determination

AbstractHydrostatic high-pressure technology (HHD) devitalizes tissue quickly and gently, without negatively affecting the structural properties. HHD-treated tissues must be cleaned from devitalized cells. A partially automated, gentle, reproducible and timesaving rinsing test setup utilizing ultrasound is demonstrated in this study. The test setup is used to clean HHD-treated bone allografts of tissue residues and prevent microbiological contamination. A rinsing procedure is investigated. Residual DNA content determination is utilized to analyze cleaned bone allograft tissue for rinsing procedure evaluation.

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