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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.
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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.
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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.
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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.
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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
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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.
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Experimental investigation of turbulent flow in a channel with the backward-facing inclined step
Příhoda, Jaromír ; Kotek, M. ; Uruba, Václav ; Kopecký, V. ; Hladík, Ondřej
The work deals with the experimental investigation of turbulent flow in a closed channel with the backward-facing inclined step. Experiments were carried by means of the PIV optical measuring method in the channel of the rectangular cross-section in the inlet part and with inclined steps of the constant height and various inclination angles for a wide range of the Reynolds number. The attention was paid especially to the separation region behind the step and to the relaxation of the shear layer after the reattachment in the outlet part of the channel. The dependence of the length of the separation region on the inclination step angle. Optical measurements were completed by the measurement of static pressure distribution in the inlet and outlet part of the channel to estimate energy losses.
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Experimental investigation of a control synthetic jet
Němcová, L. ; Kordík, Jozef ; Trávníček, Zdeněk ; Kopecký, V.
Synthetic jets were used in previous studies to control a continuous round air jet. This study focuses on the single synthetic jet, which is measured using Constant Temperature Anemometry (CTA) and Particle Image Velocimetry (PIV). Velocity profiles and frequency characteristics of the single synthetic jet are discussed and the velocity maps at frequencies of 30 Hz, 81 Hz and 190 Hz are presented. Finally, velocity, flow rate and momentum coefficients featured the present flow control are evaluated, and examples of actively controlled round air jet are put on. The results confirm efficiency of the present flow control method.
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Měření piezoelektrického aktuátoru pro posun textilií metodou digitální holografie s frekvenčně posunutou referenční vlnou
Lédl, Vít ; Václavík, J. ; Rusín, L. ; Erhart, J. ; Kopecký, V.
The actuator for moving the fabric is under development. It is necessary to characterize its properties. Time average holographic interferometry seems to be suitable tool for this purpose. However it is impossible with standard technique to resolve amplitudes in tens of microns, which are characteristic for the operation of the actuator. Time average holographic interferometry with frequency shifted reference wave has to be applied to solve this problem. Few expositions of the vibrating actuator have been captured with different frequency shift of the reference wave. Bessel functions obtained from these interferograms were fitted together by the automated software. The shape and the amplitude of the movement were successfully measured in whole area of actuator.
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