Form Factor for the Top-Level Comparison of the Condition of Supply of High-Pressure Compressor Blades

2012 ◽  
Author(s):  
Marcus Schrade ◽  
Stephan Staudacher ◽  
Matthias Weißschuh ◽  
Matthias Voigt
Keyword(s):  
High Pressure ◽  
Form Factor ◽  
Gas Turbines ◽  
Principal Component ◽  
Complex Geometries ◽  
Compressor Blades ◽  
High Pressure Compressor ◽  
Geometric Deviations ◽  
Pressure Compressor ◽  
Component Feature

High-pressure compressor (HPC) performance and maintenance of gas turbines is influenced by blade production scatter and in-service deterioration. Complex geometries in HPC, especially at blades, yield to a large amount of component features, which individually influence performance and maintenance characteristics. This results in a highly complex and poorly observable system. Hence, the correlation of a single component feature to performance or maintenance characteristics is not purposeful and a reduction of the parameter space is advantageous. A form factor is introduced that reduces geometric deviations of component features to a scalar. Principal component analysis (PCA) of measured HPC blades is used to support the form factor concept. The meaningfulness of this approach is shown in identifying process capabilities of different forges based on the form factor.

scholarly journals Aeroelastic assessment of a highly loaded high pressure compressor exposed to pressure gain combustion disturbances

2018 ◽  
Vol 2 ◽  
pp. F72OUU
Author(s):  
Victor Bicalho Civinelli de Almeida ◽  
Dieter Peitsch
Keyword(s):  
High Pressure ◽  
Gas Turbines ◽  
Forced Response ◽  
Thermodynamic Efficiency ◽  
Efficiency Gain ◽  
Aerodynamic Damping ◽  
High Pressure Compressor ◽  
Pressure Gain Combustion ◽  
Pressure Compressor ◽  
Highly Loaded

A numerical aeroelastic assessment of a highly loaded high pressure compressor exposed to flow disturbances is presented in this paper. The disturbances originate from novel, inherently unsteady, pressure gain combustion processes, such as pulse detonation, shockless explosion, wave rotor or piston topping composite cycles. All these arrangements promise to reduce substantially the specific fuel consumption of present-day aeronautical engines and stationary gas turbines. However, their unsteady behavior must be further investigated to ensure the thermodynamic efficiency gain is not hindered by stage performance losses. Furthermore, blade excessive vibration (leading to high cycle fatigue) must be avoided, especially under the additional excitations frequencies from waves traveling upstream of the combustor. Two main numerical analyses are presented, contrasting undisturbed with disturbed operation of a typical industrial core compressor. The first part of the paper evaluates performance parameters for a representative blisk stage with high-accuracy 3D unsteady Reynolds-averaged Navier-Stokes computations. Isentropic efficiency as well as pressure and temperature unsteady damping are determined for a broad range of disturbances. The nonlinear harmonic balance method is used to determine the aerodynamic damping. The second part provides the aeroelastic harmonic forced response of the rotor blades, with aerodynamic damping and forcing obtained from the unsteady calculations in the first part. The influence of blade mode shapes, nodal diameters and forcing frequency matching is also examined.

Corrosion Studies of High and Low Pressure Compressor Blades of a Gas Turbine

2005 ◽  
Author(s):  
A. Boschetti ◽  
E. Y. Kawachi ◽  
M. A. S. Oliveira
Keyword(s):  
High Pressure ◽  
Gas Turbine ◽  
Low Pressure ◽  
Compressor Blade ◽  
Compressor Blades ◽  
X Ray ◽  
Corrosion Studies ◽  
High Pressure Compressor ◽  
Pressure Compressor ◽  
Base Superalloy

This work presents preliminary results of corrosion studies for three blades, one of the low pressure compressor and two of two different stages of the high pressure compressor of a gas turbine, which has been operating for 5,000 hours. Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDS), X-ray diffraction (XRD), Electrochemical Impedance Spectroscopy (EIS) in aqueous solution containing chloride, and Atomic Absorption Spectrometry (AAS) were used to characterize the blades surfaces. The SEM and EDS results showed that the homogeneity and amount of contaminants, such as sodium, potassium, calcium, magnesium, chloride and sulphur are bigger in the high pressure compressor blade surfaces than in the low pressure compressor blade surface. The EIS results showed that the degradation process in turbine compressor blades increases with the temperature and pressure increase inside the compressors and depends of the blade composition. The low pressure compressor blade, which was made of a Ti base superalloy exhibited smaller corrosion resistance (smallest charge transfer resistance value (Rct)) than the two high pressure compressor blades, which were made of a Fe base superalloy. However, despite of its lower resistance to corrosion, after 5,000 hours of service, the low pressure compressor blade did not present pitting corrosion while the high pressure compressor blades did.

Analysis and Optimization of Robotized Grinding of Titanium High Pressure Compressor Blades

2016 ◽  
Author(s):  
M. Meshreki ◽  
Z. Shi ◽  
F. Arrien ◽  
M. H. Attia
Keyword(s):  
High Pressure ◽  
Natural Frequency ◽  
Dynamic Characteristics ◽  
Robotic Arm ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Compressor Blades ◽  
Part Quality ◽  
High Pressure Compressor ◽  
Pressure Compressor

An analysis for a robotized grinding process of aerospace Titanium high pressure compressor blades was performed. In this process, the blade was grabbed on the robotic arm. A Scotch-Brite grinding wheel, on a pneumatic actuator, was used to grind the edges of the blades. The objective of this research work was to identify the major factors that influence the accuracy of the process and the final part quality. This objective was achieved by analyzing the dynamic characteristics of the wheel grabbed on the motor as well as analyzing the dynamic characteristics of the blade grabbed on the robotic arm. The frequency response functions (FRF) were identified at different robot configurations and positions. In addition, the vibrations of the various system components during the grinding process were monitored and analyzed to determine the effect of the speed on the relative vibrations between the workpiece and the wheel. Considering the dynamics of the wheel and the motor, rotational speed ranges were recommended. It was found that the vibrations of the grinding process were higher at two ranges: The first corresponds to the first natural frequency of the robot and the second corresponds to the first natural frequency of the wheel and the second natural frequency of the robot. By avoiding these ranges, part quality within the specified tolerances was obtained.

scholarly journals Part Load Performance of the Intercooled Two-Shaft Gas Turbine With Power Output at Constant Speed on the High-Pressure Shaft

1987 ◽  
Author(s):  
N. Gasparovic ◽  
J.-W. Kim
Keyword(s):  
High Pressure ◽  
Power Output ◽  
Gas Turbines ◽  
Internal Heat ◽  
Constant Speed ◽  
Inlet Temperature ◽  
Part Load ◽  
Internal Heat Exchanger ◽  
High Pressure Compressor ◽  
Pressure Compressor

The general analysis of the part load performance of gas turbines indicates that the intercooled cycle with two shafts and power output at constant speed on the high-pressure shaft can have a good part load efficiency. Calculations with fixed geometry of the turbomachines show an intolerable increase of the turbine inlet temperature above the permissible level. By introducing variable geometry in the turbomachines, this disadvantage can be overcome. With variable inlet guide vanes at the high-pressure compressor an excellent part load performance is achieved. Further improvements are possible by adding an internal heat exchanger.

Probabilistic CFD Simulation of a High-Pressure Compressor Stage Taking Manufacturing Variability Into Account

2010 ◽  
Author(s):  
Alexander Lange ◽  
Matthias Voigt ◽  
Konrad Vogeler ◽  
Henner Schrapp ◽  
Erik Johann ◽  
...  
Keyword(s):  
High Pressure ◽  
Point Cloud ◽  
Cfd Simulation ◽  
Three Dimensional ◽  
Parameter Vector ◽  
Compressor Blades ◽  
The Monte Carlo Method ◽  
High Pressure Compressor ◽  
Pressure Compressor

The present paper addresses a non-deterministic CFD simulation of a high-pressure compressor (HPC) stage. The investigation focuses on the determination of the influence of the manufacturing scatter of compressor blades on the aerodynamic performance of the analyzed HPC stage. A set of 150 blades was scanned using an optical 3D digitizer to obtain a three-dimensional point cloud representing the surface of the blades. Classical profile parameters were identified at several sections of constant spanwise coordinate. The radial stacking of these parameters forms a parameter vector that constructs the airfoil model of each scanned blade. Consequently these parameters were used to define the geometric variability of the entire measured blade set. A statistical analysis of the distribution of these parameters defines the input data of the probabilistic 3D CFD simulation. The Monte-Carlo method is used to identify the scatter of the performance values of the HPC stage and their sensitivity to the geometric variability of profile parameters.

Impact of Nonuniform Stagger Angle Distribution on High-Pressure Compressor Rotor Performance

2018 ◽  
Author(s):  
Siyu Zheng ◽  
Jinfang Teng ◽  
Yu Wu ◽  
Fushui Guo ◽  
Shaopeng Lu ◽  
...  
Keyword(s):  
High Pressure ◽  
Nonuniform Distribution ◽  
Angle Distribution ◽  
Compressor Blades ◽  
High Pressure Compressor ◽  
Manufacturing Tolerances ◽  
Total Performance ◽  
Stagger Angle ◽  
Pressure Compressor ◽  
Sinusoidal Function

The focus of the present study is to find a solution to the manufacturing tolerances of rotor stagger angle in the high pressure compressor. The manufacturing processes of compressor blades may lead the stagger angle to be out of tolerance, which would reduce the performance of the high-pressure compressor. Meanwhile, the assembly may cause the nonuniform distribution of the variable blades. To investigate the influence of stagger angle variability and its nonuniform distribution in multiple passages, amount of 3D numerical simulations of a high pressure compressor rear-stage rotor were conducted in the present paper. The Gaussian Probabilistic Density Function was used to obtain the sampled blades with variable stagger angles, and then the blades were randomly allocated in a single passage to a half period, respectively. Numerical results show that with the increase of passage number, the total performance varies more stably. In order to get an appropriate tolerance range of the stagger angle to control the deterioration of the total performance, different ranges were tried, and [−1.5°, +1.5°] was determined as the final range to do further analyses. The different stagger angle distribution along the circumferential direction of a specific group of several sampled blades led to the different performance variations. When the stagger angle distribution approximately satisfied the sinusoidal function during assembly, the rotor performance was better than other distributions. Hence, the sinusoidal function during assembly is an effective solution to the manufacturing tolerances of rotor stagger angle.

Numerical Investigations of a High Pressure Compressor Exposed to Unsteady Pressure Gain Combustion Employing Data-Driven Methods

2021 ◽  
Author(s):  
Victor Bicalho Civinelli de Almeida ◽  
Dieter Peitsch
Keyword(s):  
High Pressure ◽  
Gas Turbines ◽  
Data Driven ◽  
Thermodynamic Efficiency ◽  
Dynamic Mode ◽  
Numerical Work ◽  
High Pressure Compressor ◽  
Pressure Gain Combustion ◽  
Flow Features ◽  
Pressure Compressor

Abstract Pressure gain combustion (PGC) should substantially improve the thermodynamic efficiency of gas turbines by increasing the fluid total pressure as it traverses the combustion chamber. However, PGC introduces additional unsteadiness to the intrinsically complex turbomachinery flow. A high pressure compressor, located right upstream of the PGC section, is therefore constantly exposed to flow fluctuations, experiencing drop in efficiency, increase in pressure loss as well as higher stalling and structural failure risks. This numerical work analyzes how one stage of a well-established engine, namely the NASA EEE core compressor, reacts to the disturbances induced by the potential implementation of PGC. Unsteady computational fluid dynamics are employed with boundary conditions simulating the combustion unsteadiness. The main focus of the current paper is the application of data-driven methods, including the proper orthogonal decomposition (POD) and the dynamic mode decomposition (DMD), when comparing the high pressure compressor baseline operation with the PGC-disturbed case. Representative flow features and their frequency content, not identifiable with typical methods such as phase-averaging, are easily extracted from snapshots sequences. The results not only allow the identification of the most relevant coherent structures present in the unsteady flow, but also show how they change in the presence of PGC. This contribution sheds light on how novel PGC technology can be integrated with turbomachinery components, identifying modifications in the main flow features with the use of advanced decomposition techniques.

Numerical Investigation of Vortex Reducer Flows in the High Pressure Compressor of Modern Aeroengines

2002 ◽  
Author(s):  
Dieter Peitsch ◽  
Manuela Stein ◽  
Stefan Hein ◽  
Reinhard Niehuis ◽  
Ulf Reinmo¨ller
Keyword(s):  
High Pressure ◽  
Gas Turbines ◽  
Efficient Operation ◽  
Pressure Losses ◽  
High Pressure Compressor ◽  
Air System ◽  
The Difference ◽  
Secondary Air ◽  
Set Up ◽  
Pressure Compressor

Modern jet engines require very high cycle temperatures for efficient operation. In turn, cooling air is needed for the turbine, since the materials are not yet capable of taking these temperatures. Air is taken from the compressor for the purpose of cooling and turbine rim sealing, bypassing the main combustion circuit. Since this affects the efficiency of the engine in a negative manner, measures are taken to reduce the amount of air to an absolute minimum. These measures include the investigation of reducing pressure losses within the involved subsystems. One of these subsystems in the BR700 aeroengine series of Rolls-Royce is the vortex reducer device, which delivers bleed air to the secondary air system of the engine. The German government has set up a research project, aiming for an overall improvement of aeroengines. This program, Engine 3E, where 3E reflects Efficiency, Economy and Environment, concentrates on the main components of gas turbines. Programmes for the high pressure turbine and for the combustion chamber have been set up. The high pressure compressor has been identified as key component as well. A new 9-stage compressor is being developed at Rolls-Royce Deutschland to adress the respective needs. From the point of view of the secondary air system, the vortex reducer in this component plays a major role with respect to the efficient use of cooling and sealing air. Rolls-Royce Deutschland has performed CFD studies on the performance of different vortex reducer geometries, which currently are considered for incorporation into the future engine. The results of these investigations wil be converted into more simple design rules for proper reflection of the behaviour of this system for future designs. The paper presents the set up of the geometries, the applied boundary conditions as well as the final results. To tackle the difference between a high pressure compressor rig and a typical two-shaft engine, a dedicated investigation to assess the difference between a pure high pressure core without an internal shaft and a realistic high/low pressure shaft configuration has been carried out and is included in the paper. Recommendations to improve the design with respect to minimized pressure losses will be shown as well.

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