Detection and manipulation of the transverse motion of neutral molecules in a Stark decelerator

Fraunhofer diffraction pattern from a circular aperture with the diameter of 10µm was observed using an optical fiber microprobe. The optical fiber microprobe started to detect optical power when the distance between the probe and the circular aperture was more than 292µm. When the probe was moved in a lateral motion, the light propagation showed a Bessel function profile. When the optical fiber microprobe was moved from 293µm to 309µm from the centre of the circular aperture in a transverse motion, the power detected was not consistent with a continuation of maxima and minima due to the effect of light propagation from the circular aperture. We also observed that the distance between the probe and the centre of the circular aperture was directly proportional with the radius of focused spot and inversely proportional with the Fresnel number.

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Messung der Kolbensekundärbewegung an Verbrennungsmaschinen / Measuring piston transverse motion in internal combustion engines

tm - Technisches Messen ◽

10.1524/teme.1981.48.jg.273 ◽

1981 ◽

Vol 48 (JG) ◽

Author(s):

Helmut TSCHÖKE

Keyword(s):

Internal Combustion Engines ◽

Internal Combustion ◽

Transverse Motion ◽

Combustion Engines

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Resolving directional ambiguity in dynamic light scattering-based transverse motion velocimetry in optical coherence tomography

Optics Letters ◽

10.1364/ol.39.000521 ◽

2014 ◽

Vol 39 (3) ◽

pp. 521 ◽

Cited By ~ 17

Author(s):

Brendan K. Huang ◽

Michael A. Choma

Keyword(s):

Optical Coherence Tomography ◽

Light Scattering ◽

Dynamic Light Scattering ◽

Transverse Motion ◽

Optical Coherence

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Polarization and coherence of 5 to 30 Hz seismic wave fields at a hard-rock site and their relevance to velocity heterogeneities in the crust

Bulletin of the Seismological Society of America ◽

10.1785/bssa0800020430 ◽

1990 ◽

Vol 80 (2) ◽

pp. 430-449 ◽

Cited By ~ 3

Author(s):

William Menke ◽

Arthur L. Lerner-Lam ◽

Bruce Dubendorff ◽

Javier Pacheco

Keyword(s):

Hard Rock ◽

Scale Effects ◽

Spatial Coherence ◽

Compressional Wave ◽

P Wave ◽

Transverse Motion ◽

S Wave ◽

Chemical Explosions ◽

Aperture Arrays ◽

The Waves

Abstract Except for its very onset, the P wave of earthquakes and chemical explosions observed at two narrow-aperture arrays on hard-rock sites in the Adirondack Mountains have a nearly random polarization. The amount of energy on the vertical, radial, and transverse components is about equal over the frequency range 5 to 30 Hz, for the entire seismogram. The spatial coherence of the seismograms is approximately exp(−cfΔx), where c is in the range 0.4 to 0.7 km−1Hz−1, f is frequency and Δx is the distance between array elements. Vertical, radial, and transverse components were quite coherent over the aperture of the array, indicating that the transverse motion of the compressional wave is a property of relatively large (106 m3) volumes of rock, and not just an anomaly caused by a malfunctioning instrument, poor instrument-rock coupling, or out-crop-scale effects. The spatial coherence is approximately independent of component, epicentral azimuth and range, and whether P- or S-wave coda is being considered, at least for propagation distances between 5 and 170 km. These results imply a strongly and three-dimensionally heterogeneous crust, with near-receiver scattering in the uppermost crust controlling the coherence properties of the waves.

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Dynamics of Spinning Disc Parametrically Excited by Noise

Volume 7B: 17th Biennial Conference on Mechanical Vibration and Noise ◽

10.1115/detc99/vib-8099 ◽

1999 ◽

Author(s):

Narayanan Ramakrishnan ◽

N. Sri Namachchivaya

Keyword(s):

Equations Of Motion ◽

Planck Equation ◽

Stochastic Averaging ◽

Transverse Motion ◽

Probability Density Distribution ◽

Integral Of Motion ◽

Parametrically Excited ◽

One Dimensional ◽

Small Intensity ◽

Spinning Disc

Abstract The nonlinear dynamics of a circular spinning disc parametrically excited by noise of small intensity is investigated. The governing PDEs are reduced using a Galerkin reduction procedure to a two-DOF system of ODEs which, govern the transverse motion of the disc. The dynamics is simplified by exploiting the S1 invariance of the equations of motion of the reduced system and further, reduced by performing stochastic averaging. The resulting one-dimensional Markov diffusive process is studied in detail. The stationary probability density distribution is obtained by solving the Fokker-Planck equation along with the appropriate boundary conditions. The boundary behaviour is studied using an asymptotic approach. Some aspects of dynamical and phenomenological bifurcations of the stationary solution are also investigated. The scheme of things presented here can be applied in principle to a four-dimensional Hamiltonian system possessing one integral of motion in addition to the hamiltonian and having one fixed point.

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Strong Azimuthal Combustion Instabilities in a Spray Annular Chamber With Intermittent Partial Blow-Off

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.4037824 ◽

2017 ◽

Vol 140 (3) ◽

Cited By ~ 21

Author(s):

Kevin Prieur ◽

Daniel Durox ◽

Thierry Schuller ◽

Sébastien Candel

Keyword(s):

Light Intensity ◽

High Speed ◽

Transverse Velocity ◽

Pressure Fluctuations ◽

Pressure Sensors ◽

Nodal Line ◽

Operating Conditions ◽

Acoustic Energy ◽

Transverse Motion ◽

Azimuthal Mode

This article reports experiments carried out in the MICCA-spray combustor developed at EM2C laboratory. This system comprises 16 swirl spray injectors. Liquid n-heptane is injected by simplex atomizers. The combustion chamber is formed by two cylindrical quartz tubes allowing full optical access to the flame region and it is equipped with 12 pressure sensors recording signals in the plenum and chamber. A high-speed camera provides images of the flames and photomultipliers record the light intensity from different flames. For certain operating conditions, the system exhibits well defined instabilities coupled by the first azimuthal mode of the chamber at a frequency of 750 Hz. These instabilities occur in the form of bursts. Examination of the pressure and the light intensity signals gives access to the acoustic energy source term. Analysis of the phase fluctuations between the two signals is carried out using cross-spectral analysis. At limit cycle, large pressure fluctuations of 5000 Pa are reached, and these levels persist over a finite period of time. Analysis of the signals using the spin ratio indicates that the standing mode is predominant. Flame dynamics at the pressure antinodal line reveals a strong longitudinal pulsation with heat release rate oscillations in phase and increasing linearly with the acoustic pressure for every oscillation levels. At the pressure nodal line, the flames are subjected to large transverse velocity fluctuations leading to a transverse motion of the flames and partial blow-off. Scenarios and modeling elements are developed to interpret these features.

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