Key Technique of Tip Clearance Measurement for Rotational Blades

2008 ◽  
Vol 381-382 ◽  
pp. 427-430 ◽  
Author(s):  
Yu Zhen Ma ◽  
F.J. Duan ◽  
Yi Zhong Zheng ◽  
Chang Sheng Ai ◽  
S.H. Ye
Keyword(s):  
Scattered Light ◽  
Measurement Techniques ◽  
Tip Clearance ◽  
Fiber Optic Sensor ◽  
Measuring System ◽  
Radial Clearance ◽  
Single Bundle ◽  
Contact Mode ◽  
Measurement Results ◽  
Beam Delivery

It’s an important problem for power industry; energy industry, aviation and shipping to real-time measure the rotating blades’ tip clearance of engine. The conventional measurement techniques have different limitations. To achieve applied level for tip clearance measurement technique, according to the use request and application environment of tip clearance sensor, a new fiber-optic sensor was put forward to measure the blade tip radial clearance of engine in non-contact mode. The sensor was consist of single-bundle transmitting fiber in the center for laser beam delivery and three groups receiving fibers located in all around for collecting the scattered light. The sensor can not only eliminate the effect to measurement results of light source fluctuation and reflectivity variety of tip surface, but also reduce the effect of angle between the tip surface and sensor end face to measurement results. From the measurement results obtained from sensor on different clearance points, it proves that the sensor measuring system has well feasibility and reliability in blades tip clearance detection.

Novel Dynamic Rotor and Blade Deformation and Vibration Monitoring Technique

2011 ◽  
Vol 134 (1) ◽  
Author(s):  
Thorsten Pfister ◽  
Philipp Günther ◽  
Florian Dreier ◽  
Jürgen Czarske
Keyword(s):  
Moving Objects ◽  
Measurement Techniques ◽  
Operating Conditions ◽  
Tip Clearance ◽  
Fiber Optic Sensor ◽  
Vibration Monitoring ◽  
Rotor Speed ◽  
Out Of Plane ◽  
High Measurement ◽  
Blade Tip

Monitoring rotor deformations and vibrations dynamically is an important task for improving both the safety and the lifetime as well as the energy efficiency of motors and turbo machines. However, due to the high rotor speed encountered in particular at turbo machines, this requires concurrently high measurement rate and high accuracy, which is hardly possible to achieve with currently available measurement techniques. To solve this problem, in this paper, we present a novel nonincremental interferometric optical sensor that measures simultaneously the in-plane velocity and the out-of-plane position of laterally moving objects with micrometer precision and concurrently with microsecond temporal resolution. It will be shown that this sensor exhibits the outstanding feature that its measurement uncertainty is generally independent of the object velocity, which enables precise deformation and vibration measurements also at high rotor speed. Moreover, this sensor does not require an in situ calibration and it allows a direct measurement of blade velocity variations in contrast to blade tip timing systems. For application under harsh environmental conditions such as high temperatures, a robust and miniaturized fiber-optic sensor setup was developed. To demonstrate the capability of this sensor, measurements of tip clearance changes and rotor blade vibrations at varying operating conditions of a transonic centrifugal compressor test rig at blade tip velocities up to 600 m/s are presented among others.

Novel Dynamic Rotor and Blade Deformation and Vibration Monitoring Technique

2011 ◽  
Author(s):  
Thorsten Pfister ◽  
Philipp Gu¨nther ◽  
Florian Dreier ◽  
Ju¨rgen Czarske
Keyword(s):  
Moving Objects ◽  
Measurement Techniques ◽  
Operating Conditions ◽  
Tip Clearance ◽  
Fiber Optic Sensor ◽  
Vibration Monitoring ◽  
Rotor Speed ◽  
Out Of Plane ◽  
High Measurement ◽  
Blade Tip

Monitoring rotor deformations and vibrations dynamically is an important task for improving both the safety and the lifetime as well as the energy efficiency of motors and turbo machines. However, due to the high rotor speed encountered in particular at turbo machines, this requires concurrently high measurement rate and high accuracy, which is hardly possible to achieve with currently available measurement techniques. To solve this problem, in this paper, we present a novel non-incremental interferometric optical sensor that measures simultaneously the in-plane velocity and the out-of-plane position of laterally moving objects with micrometer precision and concurrently with microsecond temporal resolution. It will be shown that this sensor exhibits the outstanding feature that its measurement uncertainty is generally independent of the object velocity, which enables precise deformation and vibration measurements also at high rotor speed. Moreover, this sensor does not require an in situ calibration and it allows a direct measurement of blade velocity variations in contrast to BTT systems. For application under harsh environmental conditions such as high temperatures, a robust and miniaturized fiber-optic sensor setup was developed. To demonstrate the capability of this sensor, measurements of tip clearance changes and rotor blade vibrations at varying operating conditions of a transonic centrifugal compressor test rig at blade tip velocities up to 600 m/s are presented amongst others.

A New Capacitive Sensing System for Roundness Measurement

2013 ◽  
Vol 662 ◽  
pp. 754-757 ◽  
Author(s):  
Yu Zhen Ma ◽  
Xin Hua Wang ◽  
Hong Min Li ◽  
Xiao Dong ◽  
Yan Hui Kang
Keyword(s):  
Capacitive Sensor ◽  
Measuring System ◽  
Capacitive Sensing ◽  
Rotating Shaft ◽  
Contact Mode ◽  
Roundness Error ◽  
Sensing System ◽  
Displacement Sensors ◽  
Measurement Results ◽  
Roundness Measurement

A capacitive sensing system for measuring spindle roundness was proposed in this paper, it was different with the past method using inductive sensors and laser displacement sensors. Three capacitive displacement probes were installed circularly on the measured shaft, because of capacitive sensor with average effect in two electrode plates, it is able to overcome the affect of microscopic factors. while the shaft was rotating with a certain speed, the probes measured the shaft’s profile in non-contact mode simultaneously, then through linear combination for three output signals, the spindle error of the rotating shaft was eliminated, and the roundness error was effectively separated from the measurement results. The experiment results have verified the effectiveness of roundness error measuring system based on mutiple capacitive probes, this capacitive sensing system can be used for rotating shaft roundness measurement.

scholarly journals Redesigned Sensor Holder for an Atomic Force Microscope with an Adjustable Probe Direction

2021 ◽  
Author(s):  
Janik Schaude ◽  
Maxim Fimushkin ◽  
Tino Hausotte
Keyword(s):  
Atomic Force Microscope ◽  
Piezoelectric Actuator ◽  
High Speed ◽  
Closed Loop ◽  
Coefficient Of Thermal Expansion ◽  
Measuring System ◽  
Contact Mode ◽  
Loop Control ◽  
Atomic Force ◽  
Measuring Machine

AbstractThe article presents a redesigned sensor holder for an atomic force microscope (AFM) with an adjustable probe direction, which is integrated into a nano measuring machine (NMM-1). The AFM, consisting of a commercial piezoresistive cantilever operated in closed-loop intermitted contact-mode, is based on two rotational axes, which enable the adjustment of the probe direction to cover a complete hemisphere. The axes greatly enlarge the metrology frame of the measuring system by materials with a comparatively high coefficient of thermal expansion. The AFM is therefore operated within a thermostating housing with a long-term temperature stability of 17 mK. The sensor holder, connecting the rotational axes and the cantilever, inserted one adhesive bond, a soldered connection and a geometrically undefined clamping into the metrology circle, which might also be a source of measurement error. It has therefore been redesigned to a clamped senor holder, which is presented, evaluated and compared to the previous glued sensor holder within this paper. As will be shown, there are no significant differences between the two sensor holders. This leads to the conclusion, that the three aforementioned connections do not deteriorate the measurement precision, significantly. As only a minor portion of the positioning range of the piezoelectric actuator is needed to stimulate the cantilever near its resonance frequency, a high-speed closed-loop control that keeps the cantilever within its operating range using this piezoelectric actuator further on as actuator was implemented and is presented within this article.

scholarly journals Raman Sensor for the Determination of Gas Solubility

Physchem ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 176-188
Author(s):  
Gregor Lipinski ◽  
Markus Richter
Keyword(s):  
Carbon Dioxide ◽  
Gas Separation ◽  
Accurate Determination ◽  
Measurement Techniques ◽  
Screening Tools ◽  
Measuring System ◽  
Separation Processes ◽  
Use Of Resources ◽  
Gas Solubilities

Efficient and environmentally responsible use of resources requires the development and optimization of gas separation processes. A promising approach is the use of liquids that are designed for specific tasks, e.g., the capture of carbon dioxide or other greenhouse gases. This requires an accurate determination of gas solubilities for a broad range of temperatures and pressures. However, state of the art measurement techniques are often very time consuming or exhibit other pitfalls that prevent their use as efficient screening tools. Here, we show that the application of Raman spectroscopy through a compact measuring system can simplify data acquisition for the determination of gas solubilities in liquids. To demonstrate that this approach is expedient, we determined gas solubilities of carbon dioxide in water for three isotherms T = (288.15, 293.15, 298.15) K over a pressure range from p = (0.5–5) MPa and in three imidazolium-based ionic liquids for one isotherm T = 298.15 K at pressures from p = (0.1–5) MPa. When compared to data in the literature, all results are within the reported uncertainties of the measurement techniques involved. The developed analysis method eliminates the need for a lengthy volume or mass calibration of the sample prior to the measurements and, therefore, allows for fast screening of samples, which can help to advance gas separation processes in scientific and industrial applications.

Research on Precision Measuring System for Motor Speed

2012 ◽  
Vol 588-589 ◽  
pp. 1103-1107
Author(s):  
Yu Hai Gu ◽  
Qiu Shi Han ◽  
Xiao Li Xu ◽  
Hai Tao Zhang
Keyword(s):  
Control Systems ◽  
Precise Measurement ◽  
Serial Communication ◽  
Measuring System ◽  
Motor Speed ◽  
Precision Measuring ◽  
Measurement Results ◽  
Improve Accuracy ◽  
Improving Accuracy ◽  
Motor Control Systems

In order to improve accuracy of measuring motor speed in precision motor control systems, a method of precise measurement of speed with CPLD is proposed, which measures the truncated parts of the measured pulse on the basis of measuring raster count pulse within the equal period, and takes them as compensation, thus improving accuracy of measuring the raster pulse. In this paper, a speed measuring formula is given. Measuring system is provided with parallel and serial communication interfaces for output of measurement results.

Detecting Transition in Flat Plate Flow With Laser Interferometric Vibrometry (LIV)

2016 ◽  
Author(s):  
Pascal Bader ◽  
Wolfgang Sanz ◽  
Johannes Peterleithner ◽  
Jakob Woisetschläger ◽  
Franz Heitmeir ◽  
...  
Keyword(s):  
Flat Plate ◽  
Measurement Techniques ◽  
Transitional Zone ◽  
Transport Processes ◽  
Transitional Region ◽  
Test Cases ◽  
Laminar To Turbulent Transition ◽  
Turbulent Transition ◽  
Measurement Results ◽  
Laser Interferometric

Flow in turbomachines is generally highly turbulent. The boundary layers, however, often exhibit laminar-to-turbulent transition. Relaminarization from turbulent to laminar flow may also occur. The state of the boundary layer is important since it strongly influences transport processes like skin friction and heat transfer. It is therefore vitally important for the designer to understand the process of laminar-to-turbulent transition and to determine the position of transition onset and the length of the transitional region. In order to better understand transition and relaminarization it is helpful to study simplified test cases first. Therefore, in this paper the flow along a flat plate is experimentally studied to investigate laminar-to-turbulent transition. Measurements were performed for the different free-stream velocities of 5 m/s and 10 m/s. Several measurement techniques were used in order to reliably detect the transitional zone: the Preston tube, hot wire anemometry, thermography and Laser Interferometric Vibrometry (LIV). The first two measurement techniques are extensively in use at the institute ITTM and by other research groups. They are therefore used as a reference for validating the LIV measurement results. An advantage of the LIV technique is that it does not need any seeding of the fluid and that it is non-intrusive. Therefore this measurement technique does not influence the flow, and it can be used in narrow flow passages since there is no blockage, in contrast to probe-based measurement techniques. Further to the measurements, computational simulations were performed with the Fluent® and CFX® codes from ANSYS®, as well as with the in-house code Linars. The Menter SST k-ω turbulence model with the γ-ReΘ transition model was used in order to test its capability to predict the laminar-to-turbulent transition.

scholarly journals A frame for a computer aided inspection planning system

2015 ◽  
Vol 4 (1) ◽  
pp. 125 ◽  
Author(s):  
Wilma Polini ◽  
Giovanni Moroni
Keyword(s):  
Measurement Techniques ◽  
Coordinate Measuring Machine ◽  
Planning System ◽  
Inspection Planning ◽  
Coordinate Measurement ◽  
Measurement Results ◽  
Measuring Machine ◽  
Set Up ◽  
Almost All ◽  
Computer Aided Inspection

Coordinate Measuring Machine (CMM) inspection planning is an activity performed by well-trained operators, but different measurement techniques, using the same data analysis algorithms yield in different measurement results. This is a well-recognized source of uncertainty in coordinate measurement. A CMM, provided with an automatic inspection planning (CAIP) system, permits to implement more accurate and efficient operating procedures and to fit higher quality assurance standards and tighter production timings.In this paper we present a frame of a CAIP system, able to deal with almost all the decisional stages of CMM inspection. Moreover, original approaches have been developed and presented in inspection feature selection, part set-up, probe configuration, and path planning.

The Study of Tip Clearance of a Wide-Chord Fan Blade of a High Bypass Ratio Turbo-Fan Engine

2014 ◽  
Author(s):  
Xianghai Chai ◽  
Pinlian Han ◽  
Tongcheng Shi ◽  
Zhiqiang Wang
Keyword(s):  
Numerical Simulation ◽  
Twist Angle ◽  
Angular Acceleration ◽  
Tip Clearance ◽  
Radial Clearance ◽  
Torsional Deformation ◽  
Blade Tip ◽  
Fan Blade ◽  
Bypass Ratio ◽  
Blade Tip Clearance

The wide-chord swept fan blade (WCSFB) has been extensively used in a advanced high bypass ratio turbofan engines. This paper explores the nature of WCSFB tip clearance. From the static analysis, it is found that the tip radial clearance at leading and trailing edge of WCSFB will be reduced with either bending or torsional deformation of the blade. And the change of the tip radial clearances varies with the twist angle. In this study, dynamic response of the WCSFB with different angular accelerations of the engine has been analyzed. It shows that when the angular acceleration of the fan rotor reaches a certain level, considerable bending and torsional deformation of the blade will occur, accompanied by the reduction of the tip radial clearance, which may lead to abnormal rubbing/impact between the blade tip and the casing. This may cause severe consequence for the blade and casing of the engine. The numerical simulation results show that the rubbing/impact between the WCSFB tip and the casing under angular acceleration loads can lead to local buckling of the tip leading edge of the blade, which will cause severe damage at the blade tip. Moreover, the influence of vibration and mass imbalance of the rotor on the fan blade tip clearance is also analyzed. In this paper, the results of a rig test under irregular acceleration for the WCSFB rotor is also presented, which validates the analytical results. The numerical simulation and test results will assist the blade tip clearance design to reflect the nature of the WCSFB under irregular acceleration to ensure safety.

Experimental Investigation of a Single Stage Axial Flow Compressor With Controlled Diffusion Airfoils

1996 ◽  
Author(s):  
S. Pieper ◽  
J. Schulte ◽  
A. Hoynacki ◽  
H. E. Gallus
Keyword(s):  
Pressure Field ◽  
Flow Behavior ◽  
Measurement Techniques ◽  
Three Dimensional ◽  
Tip Clearance ◽  
Time Dependent ◽  
Suction Surface ◽  
Average Technique ◽  
Unsteady Pressure ◽  
Controlled Diffusion

In order to verify an inverse design concept for modern compressor bladings, a subsonic compressor front stage with IGV was investigated. One objective of the design was to survey the flow field in detail, with emphasis on 3D viscous and unsteady aspects of the flow. Therefore, the compressor was equipped with various steady and unsteady measurement techniques. Additionally, a compressor design was chosen that allows an extension up to three stages with regard to the investigation of multistage axial compressor flow behavior. Test results of the steady measurements are discussed for IGV, rotor, and stator flow at design conditions as well as the overall stage performance. The measurements of the steady flow behavior confirm the expected design performance and show the high potential of the controlled diffusion airfoil concept. Only at the side walls near hub and casing there are some differences between design and measurement due to the complex three dimensional flow. For the study of unsteady effects, detailed measurements using hot-wire probes, glue-on hot-films, and semiconductor pressure transducers were performed. All measurements are evaluated using the ensemble-average technique. The results show how the boundary layers of the inlet guide vanes and stator blades develop in a flow that is periodically disturbed by the rotor. Time-dependent pressure distributions at midspan of both stators are described. In addition, the unsteady pressure field at the casing above the rotor was investigated. The minimum wall pressure is located away from the blade suction surface. The effects of tip clearance flow on the performance are presented. The radial extent covers 15% span from the tip. At rotor exit, the unsteady pressure field and the time-dependent three-dimensional velocity vectors illustrate the salient features of the viscous flow associated with the rotor.

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