Centrifugal compressors produce high pressure ratio and rotate at speeds. So, a tiny unbalance can produce severe vibration. In this paper, effects of impeller gap on rotor vibration in a high speed centrifugal compressor is investigated. For this purpose, a numerical and experimental analysis are carried out. The moving reference frame method in FLUENT software is used for modeling of geometri...

This paper deals with comfort in diesel cars running at idle. A bench was used to reproduce the vertical vibrations of the seat, the vibrations of the steering wheel and the noise measured at the driver’s ears. Two paired comparison tests were carried out using stimuli recorded in seven cars equipped with 3 or 4 cylinder engines. In the first one, subjects were exposed to seat vertical vibratio...

The N-H stretching vibrations of adenine, one of the building blocks of DNA, are studied by combining infrared absorption and nonlinear two-dimensional infrared spectroscopy with ab initio calculations. We determine diagonal and off-diagonal anharmonicities of N-H stretching vibrations in chemically modified adenosine monomer dissolved in chloroform. For the single-quantum excitation manifold, ...

In this paper, the effect of initial stress on the radial vibrations of elastic hollow cylinder with rotation is discussed. The one-dimensional equation of elastodynamic is solved in terms of radial displacement. The frequency equation is obtained when the boundaries are free; fixed and mixed boundary condition is examined numerically. The determination is concerned with the eigenvalues of the ...

Resonant Sonic Head drilling (RSHD) induces axial vibrations along the drillstring system which affect the accuracy and quality of pre-reinforcement required to tunnels excavation in complex soils. The main goal of this paper is to control these vibrations in order to improve this process. First, an infinite dimensional equations as vibration model are elaborated with Neumann boundary condition...

Scanning Tunneling Microscopy measures tunneling current from conducting surfaces. Through analysis, it is possible to make a three dimensional picture accurate on an atomic scale of a surface and probe microscopic phenomenon. The procedure is dependent on the distance between the surface of the microscope tip and the sample surface. High tolerances on a scale less than an angstrom are required...

A simulation formalism for the nonlinear response of vibrational excitons is presented and applied to the OH stretching vibrations of neat liquid H(2)O. The method employs numerical integration of the Schrodinger equation and allows explicit treatment of fluctuating transition frequencies, vibrational couplings, dipole moments, and the anharmonicities of all these quantities, as well as nonadia...

With a help of the selfconsistent Hartree-Fock-Bogoliubov (HFB) approach with the D1S effective Gogny interaction and the Generator Coordinate Method (GCM) we incorporate the transverse collective vibrations to the one-dimensional model of the fission-barrier penetrability based on the traditional WKB method. The average fission barrier corresponding to the least-energy path in the two-dimensio...