|
|
The study of magnetorheological shaft seal
Pavlíček, Dušan ; Dočkal, Aleš (referee) ; Kubík, Michal (advisor)
This thesis deals with the experimental study of magnetorheological shaft seal. The purpose of this diploma thesis is to describe the operating parameters of rotational magnetoreological shaft seal. In thesis, the effects of magnetic field and shaft speed on the pressure resistance and braking torque are described. Operating parameters were measured by an experimental device. Research has shown that the magnetoreological seal is characterized by a high pressure resistant. Disadvantages are the high braking torque and leakage of carrier oil from the magnetorheological fluid. These problems have been solved by a new design of magnetic circuit, that has been identified as a magnetoreological gradient pinch seal (MRGPS).
|
|
|
The study of MR fluids sedimentation
Berka, Pavel ; Vimmr, Jan (referee) ; Roupec, Jakub (advisor)
This diploma thesis investigates the accelerated sedimentation of the magnetorheological fuids (MRFs) using centrifuge. Experiments are carried out at room temperature as well as at higher temperatures (40°C, 60°C and 80°C). The development of the new improved measuring device for the sedimentation evaulation is described. Magnetic components of the device were designed using FEM analysis. Newly designed device is verified. To accomplish the experiments at the high temperatures the new heated chamber for experimental centrifuge is designed and constructed. In the next part of the work full experiment of the accelerated sedimentation is performed. At final the empirical model of the sedimetation velocity for various accelerations and temperatures is synthesized.
|
|
|
Testing the magnetic seal
Pavlíček, Dušan ; Sabo, Karol (referee) ; Kubík, Michal (advisor)
Using magnetic fluids were implemented new devices and new technologies that are convenient alternative to existing, thanks the exceptional properties of these liquids. Currently does not exist suitable device for testing magnetic seal, and therefore this thesis deals the design of the stand for testing a magnetic seal.
|
|
| |
|
|
Magnetic fluids used in the fluids engineering
Kůrečka, Jan ; Nováková, Naděžda (referee) ; Fialová, Simona (advisor)
Magnetic fluids are unique combination of fluids and magnetic materials and they are today used in many different applications. This thesis describes the characteristics of magnetorheological (MR) fluids and ferrofluids, their differncies and possibilities of practical uses. Examples of current magnetic fluids are given and comparison of their selected properties.
|
|
|
Study on stability of bidisperse MR fluid and its magnetorheological effect
Dvořáček, Ondřej ; Mazůrek, Ivan (referee) ; Roupec, Jakub (advisor)
The diploma thesis deals with the study of the behaviour of bidisperse MR fluids. The introduction gives brief research and analysis of previously published studies. In the main part of this thesis, the sedimentation properties of monodispersions and bidispersions are investigated influencing on the primary and secondary particles size, the ratio between the fractions, the total concentration of the particles dispersed in the MR fluid and the carrier fluid viscosity. The initialization sedimentation rate is used to assess sediment stability. Subsequently, MR samples are tested on a slit-flow rheometer, and flow curves are measured at different temperatures and in the presence of various magnetic fields intensities. The MR effect is evaluated by the yield stress. The study contains results describing the behaviour of investigated MR fluid samples.
|
|
| |
|
|
Study on stability of bidisperse MR fluid and its magnetorheological effect
Dvořáček, Ondřej ; Mazůrek, Ivan (referee) ; Roupec, Jakub (advisor)
The diploma thesis deals with the study of the behaviour of bidisperse MR fluids. The introduction gives brief research and analysis of previously published studies. In the main part of this thesis, the sedimentation properties of monodispersions and bidispersions are investigated influencing on the primary and secondary particles size, the ratio between the fractions, the total concentration of the particles dispersed in the MR fluid and the carrier fluid viscosity. The initialization sedimentation rate is used to assess sediment stability. Subsequently, MR samples are tested on a slit-flow rheometer, and flow curves are measured at different temperatures and in the presence of various magnetic fields intensities. The MR effect is evaluated by the yield stress. The study contains results describing the behaviour of investigated MR fluid samples.
|
|
|
The study of magnetorheological shaft seal
Pavlíček, Dušan ; Dočkal, Aleš (referee) ; Kubík, Michal (advisor)
This thesis deals with the experimental study of magnetorheological shaft seal. The purpose of this diploma thesis is to describe the operating parameters of rotational magnetoreological shaft seal. In thesis, the effects of magnetic field and shaft speed on the pressure resistance and braking torque are described. Operating parameters were measured by an experimental device. Research has shown that the magnetoreological seal is characterized by a high pressure resistant. Disadvantages are the high braking torque and leakage of carrier oil from the magnetorheological fluid. These problems have been solved by a new design of magnetic circuit, that has been identified as a magnetoreological gradient pinch seal (MRGPS).
|
|
|
The study of MR fluids sedimentation
Berka, Pavel ; Vimmr, Jan (referee) ; Roupec, Jakub (advisor)
This diploma thesis investigates the accelerated sedimentation of the magnetorheological fuids (MRFs) using centrifuge. Experiments are carried out at room temperature as well as at higher temperatures (40°C, 60°C and 80°C). The development of the new improved measuring device for the sedimentation evaulation is described. Magnetic components of the device were designed using FEM analysis. Newly designed device is verified. To accomplish the experiments at the high temperatures the new heated chamber for experimental centrifuge is designed and constructed. In the next part of the work full experiment of the accelerated sedimentation is performed. At final the empirical model of the sedimetation velocity for various accelerations and temperatures is synthesized.
|
guest ::
