scholarly journals Multistage Simulations of the GE90 Turbine

1999 ◽  
Author(s):  
Mark G. Turner ◽  
Paul H. Vitt ◽  
David A. Topp ◽  
Sohrab Saeidi ◽  
Scott D. Hunter ◽  
...  
Keyword(s):  
High Pressure ◽  
Experimental Results ◽  
Design Environment ◽  
High Pressure Turbine ◽  
Cooling Flows ◽  
Low Pressure Turbine ◽  
Blade Row ◽  
Turbine Design ◽  
First Time ◽  
Good Agreement

The average passage approach has been used to analyze three multistage configurations of the GE90 turbine. These are a high pressure turbine rig, a low pressure turbine rig and a full turbine configuration comprising 18 blade rows of the GE90 engine at takeoff conditions. Cooling flows in the high pressure turbine have been simulated using source terms. This is the first time a dual-spool cooled turbine has been analyzed in 3D using a multistage approach. There is good agreement between the simulations and experimental results. Multistage and component interaction effects are also presented. The parallel efficiency of the code is excellent at 87.3% using 121 processors on an SGI Origin for the 18 blade row configuration. The accuracy and efficiency of the calculation now allow it to be effectively used in a design environment so that multistage effects can be accounted for in turbine design.

Study of Hot Streak Effects in a Counter-Rotating Turbine

2001 ◽  
Author(s):  
L. C. Ji ◽  
J. Z. Xu ◽  
J. Chen
Keyword(s):  
High Pressure ◽  
Heat Load ◽  
Three Dimensional ◽  
High Pressure Turbine ◽  
Design And Optimization ◽  
Low Pressure Turbine ◽  
Second Stage ◽  
Euler Solver ◽  
Hot Streak ◽  
Turbine Design

Based on its convection nature, some influences of the hot streak on a 1+1 (with inter-blade vane) counter-rotating turbine are studied by using a three-dimensional (3D) unsteady Euler solver. Emphasis is laid on the hot streak effect to the blade heat load and the clocking effects between hot streak and blade rows. One temperature distortion magnitude, two spanwise and four tangential positions, four clocking locations between vanes of first and second stage are examined. Results show that the effect of the hot streak on a counter-rotating turbine is nearly the same as a conventional turbine. However, clocking between the hot streak and the vane of the high pressure turbine (HPT) exerts significant influences on the heat load of the whole HPT stage. Also, clocking between the HPT vane and the vane of the low pressure turbine (LPT) affects the heat load of the LPT greatly. These effects cannot be captured with the steady flow assumption. So time accurate simulation about the hot streak/blade interaction must be used as a basis for the turbine design and optimization.

scholarly journals Comparison of Experimental and Numerical Transient Drop Deformation during Transition through Orifices in High-Pressure Homogenizers

2021 ◽  
Vol 5 (3) ◽  
pp. 32
Author(s):  
Benedikt Mutsch ◽  
Peter Walzel ◽  
Christian J. Kähler
Keyword(s):  
High Pressure ◽  
Visual Analysis ◽  
Imaging Technique ◽  
Extensional Flow ◽  
Droplet Breakup ◽  
Experimental Results ◽  
Drop Deformation ◽  
Droplet Deformation ◽  
Shadow Imaging ◽  
Good Agreement

The droplet deformation in dispersing units of high-pressure homogenizers (HPH) is examined experimentally and numerically. Due to the small size of common homogenizer nozzles, the visual analysis of the transient droplet generation is usually not possible. Therefore, a scaled setup was used. The droplet deformation was determined quantitatively by using a shadow imaging technique. It is shown that the influence of transient stresses on the droplets caused by laminar extensional flow upstream the orifice is highly relevant for the droplet breakup behind the nozzle. Classical approaches based on an equilibrium assumption on the other side are not adequate to explain the observed droplet distributions. Based on the experimental results, a relationship from the literature with numerical simulations adopting different models are used to determine the transient droplet deformation during transition through orifices. It is shown that numerical and experimental results are in fairly good agreement at limited settings. It can be concluded that a scaled apparatus is well suited to estimate the transient droplet formation up to the outlet of the orifice.

Influence of Hot Streak Temperature Ratio on Low Pressure Stage of a Vaneless Counter-Rotating Turbine

2007 ◽  
Author(s):  
Qingjun Zhao ◽  
Fei Tang ◽  
Huishe Wang ◽  
Jianyi Du ◽  
Xiaolu Zhao ◽  
...  
Keyword(s):  
Shock Wave ◽  
High Pressure ◽  
Secondary Flow ◽  
Low Pressure ◽  
Turbine Rotor ◽  
Temperature Ratio ◽  
High Pressure Turbine ◽  
Pressure Stage ◽  
Low Pressure Turbine ◽  
Hot Streak

In order to explore the influence of hot streak temperature ratio on low pressure stage of a Vaneless Counter-Rotating Turbine, three-dimensional multiblade row unsteady Navier-Stokes simulations have been performed. The predicted results show that hot streaks are not mixed out by the time they reach the exit of the high pressure turbine rotor. The separation of colder and hotter fluids is observed at the inlet of the low pressure turbine rotor. After making interactions with the inner-extending shock wave and outer-extending shock wave in the high pressure turbine rotor, the hotter fluid migrates towards the pressure surface of the low pressure turbine rotor, and the most of colder fluid migrates to the suction surface of the low pressure turbine rotor. The migrating characteristics of the hot streaks are predominated by the secondary flow in the low pressure turbine rotor. The effect of buoyancy on the hotter fluid is very weak in the low pressure turbine rotor. The results also indicate that the secondary flow intensifies in the low pressure turbine rotor when the hot streak temperature ratio is increased. The effects of the hot streak temperature ratio on the relative Mach number and the relative flow angle at the inlet of the low pressure turbine rotor are very remarkable. The isentropic efficiency of the Vaneless Counter-Rotating Turbine decreases as the hot streak temperature ratio is increased.

Design of an Intermediate Turbine Duct Downstream of a High Pressure Turbine

2016 ◽  
Author(s):  
Chaoshan Hou ◽  
Hu Wu
Keyword(s):  
High Pressure ◽  
Three Dimensional ◽  
Low Pressure ◽  
Aerodynamic Load ◽  
Duct Flow ◽  
Original Design ◽  
High Pressure Turbine ◽  
Intermediate Turbine Duct ◽  
Low Pressure Turbine ◽  
Inlet Conditions

The flow leaving the high pressure turbine should be guided to the low pressure turbine by an annular diffuser, which is called as the intermediate turbine duct. Flow separation, which would result in secondary flow and cause great flow loss, is easily induced by the negative pressure gradient inside the duct. And such non-uniform flow field would also affect the inlet conditions of the low pressure turbine, resulting in efficiency reduction of low pressure turbine. Highly efficient intermediate turbine duct cannot be designed without considering the effects of the rotating row of the high pressure turbine. A typical turbine model is simulated by commercial computational fluid dynamics method. This model is used to validate the accuracy and reliability of the selected numerical method by comparing the numerical results with the experimental results. An intermediate turbine duct with eight struts has been designed initially downstream of an existing high pressure turbine. On the basis of the original design, the main purpose of this paper is to reduce the net aerodynamic load on the strut surface and thus minimize the overall duct loss. Full three-dimensional inverse method is applied to the redesign of the struts. It is revealed that the duct with new struts after inverse design has an improved performance as compared with the original one.

The Unsteady Flow Field of a Purged High Pressure Turbine Based on Mode Detection

2017 ◽  
Author(s):  
S. Zerobin ◽  
S. Bauinger ◽  
A. Marn ◽  
A. Peters ◽  
F. Heitmeir ◽  
...  
Keyword(s):  
High Pressure ◽  
Flow Field ◽  
Unsteady Flow ◽  
Flow Behavior ◽  
Low Pressure ◽  
Pressure Probe ◽  
Special Focus ◽  
High Pressure Turbine ◽  
Low Pressure Turbine ◽  
Mode Detection

This paper presents an experimental study of the unsteady flow field downstream of a high pressure turbine with ejected purge flows, with a special focus on a flow field discussion using the mode detection approach according to the theory of Tyler and Sofrin. Measurements were carried out in a product-representative one and a half stage turbine test setup, which consists of a high-pressure turbine stage followed by an intermediate turbine center frame and a low-pressure turbine vane row. Four independent purge mass flows were injected through the forward and aft cavities of the unshrouded high-pressure turbine rotor. A fast-response pressure probe was used to acquire time-resolved data at the turbine center frame duct inlet and exit. The interactions between the stator, rotor, and turbine center frame duct are identified as spinning modes, propagating in azimuthal direction. Time-space diagrams illustrate the amplitude variation of the detected modes along the span. The composition of the unsteadiness and its major contributors are of interest to determine the role of unsteadiness in the turbine center frame duct loss generation mechanisms and to avoid high levels of blade vibrations in the low-pressure turbine which can in turn result in increased acoustic emissions. This work offers new insight into the unsteady flow behavior downstream of a purged high-pressure turbine and its propagation through an engine-representative turbine center frame duct configuration.

Experimental Investigation of Vane Clocking in a One and 1/2 Stage High Pressure Turbine

2004 ◽  
Author(s):  
Charles W. Haldeman ◽  
Michael G. Dunn ◽  
John W. Barter ◽  
Brian R. Green ◽  
Robert F. Bergholz
Keyword(s):  
High Pressure ◽  
Low Pressure ◽  
Test Facility ◽  
Maximum Efficiency ◽  
High Pressure Turbine ◽  
Data Set ◽  
Time Resolved ◽  
Low Pressure Turbine ◽  
Turbine Vane ◽  
Vane Clocking

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.

Numerical Investigation of the Effect of Tip Leakage Flow on an Aggressive S-Shaped Intermediate Turbine Duct

2009 ◽  
Author(s):  
W. Sanz ◽  
M. Kelterer ◽  
R. Pecnik ◽  
A. Marn ◽  
E. Go¨ttlich
Keyword(s):  
High Pressure ◽  
Low Pressure ◽  
Leakage Flow ◽  
Tip Leakage Flow ◽  
High Pressure Turbine ◽  
Tip Leakage ◽  
Intermediate Turbine Duct ◽  
Low Pressure Turbine ◽  
High Diffusion ◽  
Gap Height

The demand of a further increased bypass ratio of aero engines will lead to low pressure turbines with larger diameters which rotate at lower speed. Therefore, it is necessary to guide the flow leaving the high pressure turbine to the low pressure turbine at a larger diameter without any loss generating separation or flow disturbances. Due to costs and weight this intermediate turbine duct has to be as short as possible. This leads to an aggressive (high diffusion) S-shaped duct geometry. In order to investigate the influence of the blade tip gap height of a preceding rotor on such a high-diffusion duct flow a detailed measurement campaign in the Transonic Test Turbine Facility at Graz University of Technology has been performed. A high diffusion intermediate duct is arranged downstream a high-pressure turbine stage providing an exit Mach number of about 0.6 and a swirl angle of −15 degrees (counter swirl). A low-pressure vane row is located at the end of the duct and represents the counter rotating low pressure turbine at larger diameter. At the ASME 2007, results of these investigations were presented for two different tip gap heights of 1.5% span (0.8 mm) and 2.4% span (1.3 mm). In order to better understand the flow phenomena observed in the intermediate duct a detailed numerical study is conducted. The unsteady flow through the whole configuration is simulated for both gap heights as well as for a rotor with zero gap height. The unsteady data are compared at the stage exit and inside the duct to study the flow physics. The calculation of the zero gap height configuration allows to determine the influence of the tip leakage flow of the preceding rotor on the intermediate turbine duct. It turns out that for this aggressive duct the tip leakage flow has a very positive effect on the pressure recovery.

Blade-Row Interaction in a High-Pressure Turbine

2001 ◽  
Vol 17 (4) ◽  
pp. 892-901 ◽  
Author(s):  
V. S. P. Chaluvadi ◽  
A. I. Kalfas ◽  
M. R. Banieghbal ◽  
H. P. Hodson ◽  
J. D. Denton
Keyword(s):  
High Pressure ◽  
High Pressure Turbine ◽  
Blade Row ◽  
Blade Row Interaction

Aerodynamics and Heat Transfer for a Cooled One and One-Half Stage High-Pressure Turbine—Part III: Impact of Hot-Streak Characteristics on Blade Row Heat Flux

2011 ◽  
Vol 134 (1) ◽  
Author(s):  
R. M. Mathison ◽  
C. W. Haldeman ◽  
M. G. Dunn
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
High Pressure ◽  
Radial Profile ◽  
Leading Edge ◽  
Coolant Temperature ◽  
High Pressure Turbine ◽  
Blade Row ◽  
Hot Streak ◽  
The Impact

The influence of hot-streak magnitude and alignment relative to the vane leading edge on blade row heat flux is investigated for a one and one-half stage high-pressure turbine with a film-cooled vane, purge cooling, and uncooled blades. The full-stage turbine is operated at design-corrected conditions. In addition to investigating the impact of different hot-streak characteristics, this study also looks at the interaction of cooling flow with the hot streaks. This paper builds on the investigation of profile migration utilizing temperature measurements presented in Part I and the heat transfer measurements presented in Part II. Hot streaks aligned with the vane midpitch have a greater impact on blade temperatures and heat-flux values than hot streaks aligned with the vane leading edge. The leading edge hot streaks tend to be mixed out over the surface of the vane. The magnitude of the hot streak is observed to have the largest influence on the temperature and heat flux for the downstream blade. Time-accurate measurements confirm these conclusions and indicate that further analysis of the time-accurate data is warranted. Film cooling is found to impact a hot-streak profile in a way similar to that observed for a radial profile. Differences in core to coolant temperature ratio cause the uniform profile to show different coolant effects, but the overall spread of the cooling appears similar.

Aerodynamic Test Results of Controlled Pressure Ratio Engine (COPE) Dual Spool Air Turbine Rotating Rig

2000 ◽  
Author(s):  
Brian D. Keith ◽  
Dipan K. Basu ◽  
Charles Stevens
Keyword(s):  
High Pressure ◽  
Air Force ◽  
Pressure Ratio ◽  
Low Pressure ◽  
Fourth Generation ◽  
Flow Function ◽  
High Pressure Turbine ◽  
Low Pressure Turbine ◽  
Specific Thrust ◽  
Air Force Base

The Controlled Pressure Ratio Engine (COPE) is a fourth generation variable cycle engine combining the attributes of a high temperature turbojet (high dry specific thrust and low Max power SFC) with those of a turbofan (low specific thrust and low part power SFC). Variation in turbine flow function is achieved by the Controlled Area Turbine (CAT) Nozzle concept, which utilizes an innovative cam driven scheme to achieve desired flow function changes while minimizing loss in aerodynamic performance. The single stage high pressure turbine is coupled with a two stage vaneless counter-rotating low pressure turbine. The COPE Turbine System Aero/Heat Transfer Design Validation Program, jointly conducted by GE Aircraft Engines and Allison Advanced Development Company under the direction of the Air Force Research Laboratory at Wright-Patterson Air Force Base, has succeeded in demonstrating advanced turbine technologies that will be utilized on the XTE76, XTE77, and Joint Strike Fighter engines. The various phases of this program evaluated variable area nozzle performance, high pressure turbine performance under the influence of varying flow function, and dual spool testing of the vaneless, counter-rotating low pressure turbine. Evaluation of the three phases demonstrated the aerodynamic capability of these turbine technologies, meeting pre-test predictions in overall and component efficiencies.

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