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CFD simulation of the hydrokinetic energy converter using flow-induced vibrations
Vaverka, Jakub ; Bezdíček, Jiří (referee) ; Klas, Roman (advisor)
Flow-induced vibrations on bodies of different shapes are investigated by CFD simulations. The influence of the mass of the body, the spring stiffness and the value of the added damping on the dynamic behaviour of the system is evaluated. A combination of the 6DOF function and a dynamic computational mesh is used to move the body around the y-axis solely by fluid flow. The output is an evaluation of the forces acting on the body, the trajectory of the body and the possible power that the body could generate by its motion.
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Vibrace vyvolané proudem tekutiny 2008
Zolotarev, Igor ; Horáček, Jaromír
Flow-induced vibrations and noise continue to cause problems in a wide range of engineering applications, ranging from mechanical and aerospace engineering, civil engineering and ship and offshore structures to power generation and chemical processing. These proceedings bring together 139 papers dealing with a variety of topics relating to flow-induced vibration and noise, such as:vortex-induced vibration, vibration of heat-exchanger tube bundles,progress in fluid-structure interaction theory and CFD simulations, flow-sound interaction, biomechanics of voice and hearing, thermo-acoustic instabilities, vibration of hydraulic structures, gates, turbomachines nad piping systems. The contents of this publication constitute a „mixture“ of investigations by those working on the mechanisms of vibration and means of their alleviation, and studies by those in industry who draw on the present state of knowledge of these mechanisms to avoid or solve flow induced vibratin and noise problems in industrial and other applications.
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PIV měření proudění kolem samobuzeně kmitajícího modelu hlasivek
Šidlof, Petr ; Doaré, O. ; Cherfa, L. ; Lahcene, Ch. ; Chaigne, A. ; Horáček, Jaromír
A new mechanical model of vocal folds was developed in cooperation with Ecole Nationale Supérieure de Techniques Avancées, Paris. Under specific conditions, the model exhibits flow-induced vibrations, where the vocal folds collide in each cycle. The model was designed to allow dynamic, acoustic and PIV measurements synchronized with the vocal fold oscillations. The results provide interesting information about the vocal fold dynamics and about the nonstationary flow structures, developing downstream the glottis, which closes periodically.
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Physical Model of the Vocal Folds
Kryštůfek, Jan ; Bula, Vítězslav ; Horáček, Jaromír
Assuming symmetry of self-oscillations, a half physical model of the vocal folds was made. Working principle of the model is based on self-induced oscillations occurring when a critical air flow rate is crossed. Air flow rate of 0,6 l/s was used for generation of flow-induced oscillations of elastic part of the model with fundamental frequency 117 Hz. Used elastic element made of polyurethane rubber was designed and manufactured by Thomson from Purdue University (Indiana) [1], [2]. The introductory measurements were performed by using a high speed digital camera. We propose to use the model as a source of acoustic pressure for excitation of physical models of the human vocal tract.
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