National Repository of Grey Literature 95 records found  beginprevious49 - 58nextend  jump to record: Search took 0.00 seconds. 
Reconstruction of 3D PIV data in complicated experimental arrangements
Pavlík, D. ; Uruba, Václav ; Kopecký, V.
In this paper a three-dimensional reconstruction of flow field behind flat plate representing a wing\nis presented. The reconstruction is always performed for pair of 2D vector maps obtained by 3D PIV with two cameras which record measurement area from different locations. Three-dimensional reconstruction can be obtained in various ways. This paper summarizes two: the reconstruction based on the known correspondences and the reconstruction based on the knowledge of intrinsic and extrinsic parameters of cameras. The methods can be used in the cases when it is impossible to use a calibration pattern or when reconstruction by commercial software fails.
On 3D flow-structures behind an inclined plate
Uruba, Václav ; Pavlík, D. ; Procházka, Pavel P. ; Skála, Vladislav ; Kopecký, V.
Stereo PIV measurements has been performed behind the inclined plate, angle of attack 5 and\n10 deg. Occurrence and dynamics of streamwise structures behind the plate trailing edge have been studied in details using POD method. The streamwise structures are represented by vortices and low- and highvelocity regions, probably streaks. The obtained results support the hypothesis of an airfoil-flow force interaction by Hoffman and Johnson [1,2].
Proudové pole na výtoku z radiálního míchadla, porovnání LDA a PIV měření
Kysela, Bohuš ; Konfršt, Jiří ; Chára, Zdeněk ; Jašíková, D. ; Němcová, L. ; Kopecký, V.
Two velocity measurement methods in discharged stream from Rushton turbine are compared. The tested methods are LDA (Laser Doppler Anemometry) and stereo TR PIV (Time Resolved Particle Image Velocimetry). The discrepancy of evaluated data from stereo PIV affected by transforming recalculation in discharged stream is presented.
Mechanical manipulator
Kopecký, Vojtěch ; Winkler, Tomáš (referee) ; Malášek, Jiří (advisor)
The aim of this thesis is to design a mechanical manipulator. Work includes variants kinematics stroke belt conveyor, belt functional calculations belt and roller conveyor and risk analysis (the basis for the Declaration of Conformity) and FMEA analysis.
Stacking machine
Kopecký, Vojtěch ; Špička, Jiří (referee) ; Malášek, Jiří (advisor)
This thesis deal with a construction development Stacking machine which contains conveyor line German’s producer of blower machines. The description not includes only design but also computational part. My tendency is satisfy users in a maximum way.
Magnetic domains under mechanical stress in single crystal Ni-Mn-Ga
Kopecký, Vít ; Heczko, Oleg
The complexity of Ni-Mn-Ga single crystal lies in combination of ferromagnetic domain structure and ferroelastic twinned microstructure. Magnetic domain structure for different twinned microstructure was studied using magneto-optical indicator film. Different orientations of magnetic domains can be observed at the same place of the sample thanks to magnetically induced structural reorientation by movement of twin boundaries. We investigated experimentally the changes of magnetic domain structure in the vicinity of mobile a/c twin boundary.
Digital Holographic Method for Piezoelectric Transformers Vibration Analysis
Psota, Pavel ; Kopecký, V. ; Lédl, Vít ; Doleček, Roman
The paper describes a holographic method for vibration analysis in nanometer range. The method was successfully applied on different types of piezoelectric transformers and the measurement results are introduced. To proof the reliability of the method it was done a comparing simultaneous measurement of a piezoelectric component by the holographic method and the well-established single-point interferometric method. Results showing the minimal deviation of both methods are presented in the final part of the paper.
Digital holographic setup for measurement of asymmetric temperature field and tomographic reconstruction
Doleček, Roman ; Kopecký, V. ; Psota, Pavel ; Lédl, Vít
This paper presents a digital holographic multidirectional interferometric method for measurement of periodic asymmetric temperature fields. This method uses a modified Twymann-Green setup having double sensitivity. The setup employs one precisely synchronized and triggered CCD camera with a measured coherent phenomenon. That allows a large number of the phenomenon’s different projections capturing which are used for 3D tomographic reconstruction.
Measurement of Vibration Mode Structure for Adaptive Vibration Suppression System by Digital Holography
Psota, Pavel ; Lédl, Vít ; Doleček, Roman ; Mokrý, P. ; Kopecký, V.
Previously the frequency-shifted digital holographic interferometry (FSDHI) for measurement of vibration amplitudes in range of nanometers was introduced and verified by authors [1,2]. The method FSDHI addressed some of the drawbacks of the conventional methods and was used mainly for piezoelectric transformer vibration amplitudes and mode structures measurement [3]. The limiting factor for application of this method is the maximal measured value of the vibration amplitude without the risk of ambiguity. The value is approximately 80nm for the frequency doubled Nd: YAG line. Since FSDHI enables us to precisely measure vibration amplitudes over the whole inspected area with very high lateral resolution, it could also be a very useful tool for measurement of vibration amplitudes and mode structures for research in the field of adaptive suppression systems. Such a measurement would provide a necessary feedback about the system behavior.This was the reason why we put an effort
Comparison of holographic setups used in heat and mass transfer measurement
Doleček, Roman ; Psota, Pavel ; Lédl, Vít ; Vít, Tomáš ; Kopecký, V.
The authors of the paper deal with measurement of heat and mass transfer for several years and they have frequently used few techniqes for measurement of refractive index distribution based on holographic interferometry. Some of the well known techniques have been modified some and some new ones developped. Every technique could be applied with success in different type of meassurement and obviously every one has set of properties making them unique. We decided to digest few different basic techniques and describe its properties in this paper with the aim to help the reader select the proper one for their measurement. The list of techniques and its properties is not comprehensive but schould serve as a basic orientation in the field.

National Repository of Grey Literature : 95 records found   beginprevious49 - 58nextend  jump to record:
See also: similar author names
1 Kopecký, V.
3 Kopecký, Vladimír
8 Kopecký, Vojtěch
6 Kopecký, Václav
1 Kopecký, Vít
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