Characterization of the Velocity Field External to a Tube Bundle Using Spatial Filter Velocimetry Based on Variable Meshing Scheme

Exploiting minmax characterizations for nonlinear and nonoverdamped eigenvalue problems, we prove the existence of a countable set of eigenvalues converging to∞and inclusion theorems for a rational spectral problem governing mechanical vibrations of a tube bundle immersed in an incompressible viscous fluid. The paper demonstrates that the variational characterization of eigenvalues is a powerful tool for studying nonoverdamped eigenproblems, and that the appropriate enumeration of the eigenvalues is of predominant importance, whereas the natural ordering of the eigenvalues may yield false conclusions.

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Experimental characterization of the velocity field of a coaxial jet configuration

Experimental Thermal and Fluid Science ◽

10.1016/0894-1777(94)90106-6 ◽

1994 ◽

Vol 9 (2) ◽

pp. 135-146 ◽

Cited By ~ 45

Author(s):

Guido Buresti ◽

Alessandro Talamelli ◽

Paolo Petagna

Keyword(s):

Velocity Field ◽

Experimental Characterization

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Characterization of liquid refrigerant R-123 flow emerging from a flooded evaporator tube bundle

Science and Technology for the Built Environment ◽

10.1080/23744731.2018.1464349 ◽

2018 ◽

Vol 24 (9) ◽

pp. 1026-1038

Author(s):

William Asher ◽

Steven J. Eckels

Keyword(s):

Tube Bundle

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Thermal Characterization of Prototypical ICS Systems With Immersed Heat Exchangers

Solar Energy ◽

10.1115/isec2004-65030 ◽

2004 ◽

Cited By ~ 1

Author(s):

Wei Liu ◽

Jane H. Davidson ◽

F. A. Kulacki

Keyword(s):

Heat Exchangers ◽

Tube Bundle ◽

Fluid Motion ◽

Thermal Characterization ◽

Transfer Coefficients ◽

Single Tube ◽

Operating Modes ◽

Heat Transfer Coefficients ◽

Nusselt Numbers

Natural convection is measured in an enclosure that represents an integral collector storage solar system with an immersed heat exchanger. The enclosure has an aspect ratio of 9.3:1 and is inclined 30 deg to the horizontal. Heat transfer coefficients for bundles of 240 tubes are obtained for a range of transient operating modes and pitch-to-diameter ratios of 1.5, 2.4, and 3.3. Results for isothermal and stratified enclosures yield a correlation for the overall Nusselt number, NuD=(2.45±0.03)RaD0.188,230≤RaD≤9800. Nusselt numbers are three times larger than those for a similarly configured single-tube and an eight-tube bundle. This increase is attributed to stronger fluid motion within the bundle and greater overall circulation rates in the enclosure.

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Inter-Laboratory Characterization of the Velocity Field in the FDA Blood Pump Model Using Particle Image Velocimetry (PIV)

Cardiovascular Engineering and Technology ◽

10.1007/s13239-018-00378-y ◽

2018 ◽

Vol 9 (4) ◽

pp. 623-640 ◽

Cited By ~ 5

Author(s):

Prasanna Hariharan ◽

Kenneth I. Aycock ◽

Martin Buesen ◽

Steven W. Day ◽

Bryan C. Good ◽

...

Keyword(s):

Particle Image Velocimetry ◽

Velocity Field ◽

Particle Image ◽

Blood Pump ◽

Laboratory Characterization ◽

Image Velocimetry

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Versatility of a hard X-ray Kirkpatrick–Baez focus characterized by ptychography

Journal of Synchrotron Radiation ◽

10.1107/s0909049513005372 ◽

2013 ◽

Vol 20 (3) ◽

pp. 490-497 ◽

Cited By ~ 10

Author(s):

Klaus Giewekemeyer ◽

Robin N. Wilke ◽

Markus Osterhoff ◽

Matthias Bartels ◽

Sebastian Kalbfleisch ◽

...

Keyword(s):

Spatial Filter ◽

Large Field ◽

X Rays ◽

Height Profile ◽

Diffractive Imaging ◽

X Ray ◽

The Past ◽

Moderate Resolution ◽

Nano Imaging

In the past decade Kirkpatrick–Baez (KB) mirrors have been established as powerful focusing systems in hard X-ray microscopy applications. Here a ptychographic characterization of the KB focus in the dedicated nano-imaging setup GINIX (Göttingen Instrument for Nano-Imaging with X-rays) at the P10 coherence beamline of the PETRA III synchrotron at HASLYLAB/DESY, Germany, is reported. More specifically, it is shown how aberrations in the KB beam, caused by imperfections in the height profile of the focusing mirrors, can be eliminated using a pinhole as a spatial filter near the focal plane. A combination of different pinhole sizes and illumination conditions of the KB setup makes the prepared optical setup well suited not only for high-resolution ptychographic coherent X-ray diffractive imaging but also for moderate-resolution/large-field-of-view propagation imaging in the divergent KB beam.

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