Investigation of thermodiffusion phenomenon under influence of vibration using image processing approach

Thermodiffusion is the appearance of concentration gradient in a mixture when subjected to a temperature gradient. Thermodiffusion or Soret effect plays an important role in the underground reservoir distribution. Consequently, a majority of petroleum research is focused on understanding this phenomenon. There are may experimental measurements of thermodiffusion. However, measurements conducted in a microgravity environment minimize the effect of gravity and leads to accurate results. This study demonstrates the influence of vibration on thermodiffusion measurement in a microgravity environment. The aim is to show how the variation of certain parameters such as the frequency and amplitude of translational vibration as well as the temperature would impact the composition of components in the mixture of Water-Isopropanol. The Fast Fourier Transform image processing technique is used to analyse the data obtained from optical digital interferometry. Moreover, two sets of experimental runs with negative and positive Soret coefficients are tested. The analysis shows the maximum separation of components for the case without any forced vibration. Furthermore, it is shown the increase in Rayleigh number corresponds to decrease in separation of components.

Investigation of thermodiffusion phenomenon under influence of vibration using image processing approach

Thermodiffusion is the appearance of concentration gradient in a mixture when subjected to a temperature gradient. Thermodiffusion or Soret effect plays an important role in the underground reservoir distribution. Consequently, a majority of petroleum research is focused on understanding this phenomenon. There are may experimental measurements of thermodiffusion. However, measurements conducted in a microgravity environment minimize the effect of gravity and leads to accurate results. This study demonstrates the influence of vibration on thermodiffusion measurement in a microgravity environment. The aim is to show how the variation of certain parameters such as the frequency and amplitude of translational vibration as well as the temperature would impact the composition of components in the mixture of Water-Isopropanol. The Fast Fourier Transform image processing technique is used to analyse the data obtained from optical digital interferometry. Moreover, two sets of experimental runs with negative and positive Soret coefficients are tested. The analysis shows the maximum separation of components for the case without any forced vibration. Furthermore, it is shown the increase in Rayleigh number corresponds to decrease in separation of components.

Free Vibration of Single Degree of Freedom Linear Oscillator

This chapter is dedicated to understanding and studying a didactic case represented by a free vibration of a linear oscillator with a single degree of freedom. Mathematical equations of the problem will be detailed as well as the solution that goes with single degree of freedom oscillator for translational vibration for all cases: free undamped oscillator, as well as free damped oscillator, and torsional free undamped vibration passing by critical, subcritical, and over damping system. At the end of the chapter, some examples will be treated.

Energy Harvesting From the Vibration and Rotation of Host Systems Using Piezoelectric Devices

This work analyzes the energy harvested by a piezoelectric vibration energy harvester that is attached to a rotating host system, like an automotive tire, that has superposed translational vibration. The device experiences once-per-revolution dynamic excitation from rotation and, because the host system translates, additional speed-dependent excitation from input vibration. The device consists of a piezoelectric beam with a proof mass that displaces tangentially in operation so that large, troublesome centripetal accelerations can be avoided. The dynamic response and power harvested are determined in closed-form. The speed-dependent properties of the response components are determined. With excitation from rotation and vibration, the device harvests substantially more power than if the system were excited by either rotation or vibration alone. Numerical results are shown for an example device over a wide range of rotation speeds. The device can harvest 185 mW of power at its maximum when the rotation speed is near 1,000 rpm. The device provides more than 30 mW of power for speeds between 817 rpm and 1,195 rpm. Harvesting energy from vibration naturally leads to wider speed bandwidths where large amounts of power are available.

Pendekatan Eksperimen Karakteristik Respon Getaran Sistem Two Degree of Freedom dengan Penambahan Independent Dual Dynamic Vibration Absorber

Vibration is one of the problems that must be reduced in a vehicle. There are many ways to reduce vibration in vehicles, one of them is by adding Dynamic vibration absorber (DVA). While Dual Dynamic vibration absorber (dDVA) is a DVA period that is able to move in the translational direction given to the system to reduce translation vibration and when there is resonance. Translation DVA is an additional type of time used to reduce the vibration of the translation direction. So far there is not much research related to the use of translational DVA to reduce rotational vibrations as well as translation. In this study, a study was conducted related to the use of independent double translational DVA (dDVA) to reduce translation vibrations as well as rotation of the beam. The research was conducted by modeling the system obtained into mathematical equations and simulations were carried out to determine the characteristics of vibrations that arise. In the simulation, one of the DVA periods is placed at the center of the main system period, while the other DVA period is given a change between the center period and the end of the system. The results of the study show that the maximum reduction in translational vibration is 95.51% and occurs when the absorber is placed at the center of the system, while the maximum rotation vibration reduction is 56.62% and is obtained when the system is given with an arm ratio of 1 and zero.

Optimal positions of translational vibration absorbers in vibroisolation of mechanical press

The paper deals with the problem of optimizing the positions of dynamic vibration absorbers in a mechanical press subjected to harmonic excitation force. Assuming flat motion of a rigid body and small vibrations, a discrete linear dynamic model of the press with absorbers is constructed. Using the results of numerical calculations, the optimal positions of the single or two vibration absorbers tuned to the excitation frequency, for different direction of excitation force, are obtained.