National Repository of Grey Literature 3 records found  Search took 0.00 seconds. 
Magnetorheological fluid response time in shear mode
Válek, Josef ; Vimmr, Jan (referee) ; Kubík, Michal (advisor)
Magnetorheological fluids (MRF) are suspensions of (commonly) oils and carbonyl iron powder. Under magnetic field, apparent viscosity of suspension changes in short time. This so-called response time can’t be neglected in modern MR devices. Multiple response times are distinguished based on load mode. Rheological response time (MRF under shear rate) will be affected by load and composition of MRF. In this thesis, these influencing parameters are investigated, which was allowed by developing rheometer with minimal hardware response time and methodology. Gained data shows, that most affecting parameter is ratio of inner forces, described e.g., Mason number. Model of Mason number was verified for larger values, but in lower values, significant difference was observed (probably caused by different shear stress mechanism in MRF). After other investigation and clarification of model, precise prediction of MRF and MR devices behaviour will be possible, which can lead to improving their function and e.g., road safety.
Design of magnetorheological damper with asymmetric velocity characteristic
Válek, Josef ; Macháček, Ondřej (referee) ; Kubík, Michal (advisor)
This thesis aims to find optimal solution for magnetorheological damper with asymmetric force-velocity behaviour. Magnetorheological dampers represent a promising direction in the development of vibration dampers, mainly due to their adjustable damping, that depends on electric current. The asymmetric force-velocity behaviour (characteristic) then means difference while compressing or expanding damper and can be achieved by valves. Valves can be solved in mechanical, hydraulic, magnetic, electric way. This bachelor´s thesis evaluates these four ways of solution and develops conceptual solutions for their possible application. One conceptual solution is then elaborated in detail. Chosen mechanical solution with movable plate was verified by calculations and experiment. Experiments confirmed the applicability of a mechanical valve in magnetorheological systems.
System for analysing hydrological time series
Válek, Josef ; Nečaský, Martin (advisor) ; Kopecký, Michal (referee)
The aim of this work is to design and implement system for operations with time series, in particular with hydrological time series. System is developed for Fiedler-Mágr company, which specializes mostly in manufacturing hydrological measurement devices. The core of the system is REST service written in PHP and supplemented with tools for data visualization. Implementing first stage of system for on-time warning against dangerous outflow - calculating water storage of soil profiles in Liz watershed - is a part of this work. Resulting system is operational and simply extensible for use in other similar tasks. The main function of the system is to combine more time series togeather. Powered by TCPDF (www.tcpdf.org)

See also: similar author names
40 VÁLEK, Jan
3 Válek, Jakub
40 Válek, Jan
1 Válek, Jaroslav
7 Válek, Jiří
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