Radiation-Induced Buoyancy-Driven Flow in Rectangular Enclosures: Experiment and Analysis

1987 ◽  
Vol 109 (2) ◽  
pp. 427-433 ◽  
Author(s):  
B. W. Webb ◽  
R. Viskanta
Keyword(s):  
Experimental Data ◽  
Temperature Field ◽  
Theoretical Model ◽  
Radiation Flux ◽  
Convective Motion ◽  
Radiative Heating ◽  
Working Fluid ◽  
Injection Technique ◽  
Flux Divergence ◽  
Radiation Induced

Experiments have been performed to study the rate of internal radiative heating on the natural convective motion in a vertical rectangular enclosure irradiated from the side. A Mach–Zehnder interferometer has been used to determine the temperature field, and a fluorescing dye injection technique was employed to illustrate the flow structure with water as the working fluid. A theoretical model is developed for predicting the absorption of thermal radiation and the subsequent buoyancy-driven flow. Predictions based on spectral calculations for the radiation flux divergence agree well with the experimental data.

Effect of Different Input Loading Form on Structure-Born Sound Radiation

2012 ◽  
Vol 518-523 ◽  
pp. 3768-3771
Author(s):  
Zhi Yong Xie ◽  
Qi Dou Zhou ◽  
Gang Ji
Keyword(s):  
Experimental Data ◽  
Forced Vibration ◽  
Sound Radiation ◽  
Added Mass ◽  
Elastic Vibration ◽  
Simulation And Experiment ◽  
Radiation Induced ◽  
Vibration And Sound Radiation ◽  
Loading Form ◽  
Good Agreement

The exciting force’s accurate measurement of is crucial to the structure-born sound radiation. Forced vibration and sound radiation of the ribbed cylinder is examined in the anechoic room. An approach called added mass and damping method is proposed to calculate the elastic vibration and acoustic field of the cylinder. Results obtained from simulation are show to be in good agreement with the experimental data. Sound radiation induced by different input loading form is examined via simulation and experiment. And the equipollence of force and pressure acting on the base is validated.

Thermal Mapping, via Liquid Crystals, of the Temperature Field near a Heated Surgical Probe

1973 ◽  
Vol 95 (2) ◽  
pp. 250-256 ◽  
Author(s):  
T. E. Cooper ◽  
J. P. Groff
Keyword(s):  
Blood Flow ◽  
Temperature Field ◽  
Liquid Crystals ◽  
Theoretical Model ◽  
Wheatstone Bridge ◽  
Visual Display ◽  
Two Dimensional ◽  
Test Medium ◽  
One Dimensional ◽  
Water Test

This paper discusses the use of heat for producing clinical lesions in tissue and presents the design and analysis of a resistively heated surgical probe. The probe surface temperature is accurately maintained and controlled by using a Wheatstone bridge. The probe was embedded in a clear agar–water test medium, and the temperature field generated by the probe was measured with liquid crystals, a material that provides a visual display of certain isotherms. Experimental results compare within approximately 10 percent of a two-dimensional numerical solution. A one-dimensional theoretical model is also developed which examines the influence of blood flow on the temperature field.

scholarly journals Mechanisms of Jet Formation on the Giant Planets

2010 ◽  
Vol 67 (11) ◽  
pp. 3652-3672 ◽  
Author(s):  
Junjun Liu ◽  
Tapio Schneider
Keyword(s):  
Angular Momentum ◽  
Rossby Wave ◽  
Momentum Flux ◽  
Wave Generation ◽  
Heat Fluxes ◽  
Giant Planets ◽  
Radiative Heating ◽  
Flux Divergence ◽  
Low Latitude ◽  
Flow Configurations

Abstract The giant planet atmospheres exhibit alternating prograde (eastward) and retrograde (westward) jets of different speeds and widths, with an equatorial jet that is prograde on Jupiter and Saturn and retrograde on Uranus and Neptune. The jets are variously thought to be driven by differential radiative heating of the upper atmosphere or by intrinsic heat fluxes emanating from the deep interior. However, existing models cannot account for the different flow configurations on the giant planets in an energetically consistent manner. Here a three-dimensional general circulation model is used to show that the different flow configurations can be reproduced by mechanisms universal across the giant planets if differences in their radiative heating and intrinsic heat fluxes are taken into account. Whether the equatorial jet is prograde or retrograde depends on whether the deep intrinsic heat fluxes are strong enough that convection penetrates into the upper troposphere and generates strong equatorial Rossby waves there. Prograde equatorial jets result if convective Rossby wave generation is strong and low-latitude angular momentum flux divergence owing to baroclinic eddies generated off the equator is sufficiently weak (Jupiter and Saturn). Retrograde equatorial jets result if either convective Rossby wave generation is weak or absent (Uranus) or low-latitude angular momentum flux divergence owing to baroclinic eddies is sufficiently strong (Neptune). The different speeds and widths of the off-equatorial jets depend, among other factors, on the differential radiative heating of the atmosphere and the altitude of the jets, which are vertically sheared. The simulations have closed energy and angular momentum balances that are consistent with observations of the giant planets. They exhibit temperature structures closely resembling those observed and make predictions about as yet unobserved aspects of flow and temperature structures.

The structure of the Cincinnati arch as determined by short period Rayleigh waves

1969 ◽  
Vol 59 (1) ◽  
pp. 399-407
Author(s):  
Robert B. Herrmann
Keyword(s):  
Experimental Data ◽  
Theoretical Model ◽  
Layer Thickness ◽  
Rayleigh Waves ◽  
Layer Model ◽  
Depth Data ◽  
Short Period ◽  
Best Fitting ◽  
Good Agreement

Abstract The propagation of Rayleigh waves with periods of 0.4 to 2.0 seconds across the Cincinnati arch is investigated. The region of investigation includes southern Indiana and Ohio and northern Kentucky. The experimental data for all paths are fitted by a three-layer model of varying layer thickness but of fixed velocity in each layer. The resulting inferred structural picture is in good agreement with the known basement trends of the region. The velocities of the best fitting theoretical model agree well with velocity-depth data from a well in southern Indiana.

Development of a Methodology for the Evaluation of Motion Sickness Incidence in Railways

2013 ◽  
Author(s):  
Claudio Braccesi ◽  
Filippo Cianetti ◽  
Renzo Scaletta
Keyword(s):  
Experimental Data ◽  
Theoretical Model ◽  
Motion Sickness ◽  
Evaluation Method ◽  
Low Frequency ◽  
Comparison With Experimental Data

The present paper illustrates an evaluation method developed by the authors to quantify the index of motion sickness incidence (MSI) in railways motion conditions. This index is formerly defined in literature to quantify diseases coming from low frequency motions (kinetosis). The proposed method, suggested as alternative to the only one existing in reference norm, involves PCT index, well known in railways context, and weighting curves for accelerometric signals, which are also specified in railways regulations. The approach of the method, consistent with the theoretical model, developed by the authors themselves in previous works, allows to obtain MSI index versus time and/or track progressive distance. The model is validated through comparison with experimental data available in literature and with measures recorded and obtained on regular trains during tests performed in Slovenia (EU).

scholarly journals Coordination Numbers of Bivalent Ions in Organic Solvents

2021 ◽  
Vol 95 (10) ◽  
pp. 2059-2064
Author(s):  
M. A. Orekhov
Keyword(s):  
Experimental Data ◽  
Theoretical Model ◽  
Molecular Dynamic ◽  
Coordination Number ◽  
Organic Solvents ◽  
Organic Molecule ◽  
Dynamic Models ◽  
Coordination Numbers ◽  
A Value ◽  
Bivalent Ions

Abstract Molecular dynamic models are created for properties of bivalent ions in organic solvents. It is shown that molecules of the considered solvents bound to ions via oxygen atoms. A theoretical model is developed that describes the ion coordination number. The coordination number in this model is determined by the ratio between the sizes of the ion and the atom organic molecule bound to it. It is shown that the coordination number depends weakly on the solvent and strongly on the type of ion. A value of 0.13 nm is obtained for the effective size of an oxygen atom bound to a bivalent ion. The constructed theoretical model agrees with the results from molecular dynamic calculations and the available experimental data.

scholarly journals FINAL STATE INTERACTIONS IN B → ππK AND $B\to K\overline{K}K$ DECAYS

2007 ◽  
Vol 22 (02n03) ◽  
pp. 645-648
Author(s):  
L. LEŚNIAK ◽  
R. KAMIŃSKI ◽  
B. EL-BENNICH ◽  
B. LOISEAU ◽  
A. FURMAN
Keyword(s):  
Experimental Data ◽  
Theoretical Model ◽  
Unitary Representation ◽  
B Meson ◽  
Final State ◽  
B Meson Decays ◽  
Meson Decays ◽  
Neutral B Meson ◽  
Final State Interactions

Analysis of charged and neutral B meson decays into π+π-K, K+K-K and [Formula: see text] is performed using a unitary representation of the ππ and [Formula: see text] final state interactions. Comparison of the theoretical model with the experimental data of the Belle and BaBar Collaborations indicates that charming penguin contributions are necessary to describe the B → f0(980) K and B → ρ(770)0 K decays.

Experimental and Numerical Study of Transport Phenomena in a Simulated Hydrothermal Crystal Growth System of Fluid-Saturated Porous Layer

2000 ◽  
Author(s):  
D. Mishra ◽  
A. Pal ◽  
N. Nemick ◽  
A. K. Saha ◽  
V. Prasad ◽  
...  
Keyword(s):  
Temperature Field ◽  
Porous Layer ◽  
Hydrothermal System ◽  
Numerical Study ◽  
Transport Phenomena ◽  
Composite Layer ◽  
Staggered Grid ◽  
Working Fluid ◽  
Hydrothermal Crystal Growth ◽  
Numerical Predictions

Abstract A simulated, non-pressurized hydrothermal system consisting of a fluid-superposed porous layer is fabricated and used for visualization and measurement of the temperature field using liquid crystal thermography. The system is used for various boundary conditions with pure glycerine as the working fluid and the porous layer is made of 3mm diameter glass beads. Experimental data is recorded using a color CCD camera and flow visualization is obtained through a long exposure video photography. A calibration is performed to relate the temperature with scattered colors at an orthogonal angle to the incoming white light sheet. Quantitative temperature data is obtained through this calibration and compared with the numerical predictions. For numerical studies the system is modeled as a composite layer of fluid and porous charge using the Darcy-Brinkman-Forchheimer flow model. A two-dimensional curvilinear algorithm using finite volume technique with a non-staggered grid is used to simulate the temperature field and transport phenomena for various Rayleigh–Darcy number combinations of varying aspect ratio. The results, for the first time, make an attempt towards understanding the transport process in hydrothermal system through both numerical simulation and experimental validation.

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