<title>Characterization of an infrared spectrograph for noncontact thermometry applications using a sodium heat pipe blackbody</title>

Thermally driven microfluidics, that is, flow that is driven by a temperature gradient, has applications from lab-on-a-chip to electronics cooling. Development of such devices requires tools to predict and probe temperature and velocity fields. We have developed analytical, numerical, and experimental analysis tools for design and characterization of thermally driven microfluidic systems. We demonstrate these tools through the analysis of two different systems: an electrothermal microstirring biochip, and a high aspect heat pipe for cooling. First, a numerical model is developed for temperature and velocity fields, in a hybrid electrothermal-buoyancy microstirring device. An analytical tool, the electrothermal Rayleigh number, is used to further explore the relative importance of electrothermal and buoyancy driven flow. Finally, two experimental thermometry techniques are described: fluorescence thermometry and infrared thermometry. These analytical, numerical, and experimental tools are useful in the design of thermally driven microfluidic systems, as demonstrated here through the development and analysis of microstirring and heat pipe systems.

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Neutron Imaging Feasibility of Liquid Metal Coolant Behaviors Inside a High-Temperature Alloy Heat Pipe

ASME/JSME 2011 8th Thermal Engineering Joint Conference ◽

10.1115/ajtec2011-44119 ◽

2011 ◽

Cited By ~ 1

Author(s):

K. D. Kihm ◽

D. Hussey ◽

D. M. Pratt ◽

A. D. Swanson

Keyword(s):

Liquid Metal ◽

Heat Pipe ◽

Neutron Imaging ◽

Liquid Sodium ◽

Liquid Metal Coolant ◽

Beam Scattering ◽

Time Requirements ◽

Alloy Heat ◽

Metal Coolant

Experimental study has been conducted for multiscale characterization of liquid metal (Na) transport within a heat pipe using a neutron imaging technique. Feasibility of nonintrusive imaging of liquid sodium contained inside a nickel alloy heat pipe has been examined for the imaging resolution, exposure time requirements, background noises, and other basic considerations associated with neutron beam scattering. Preliminary results of neutron imaging show fairly acceptable feasibility of neutron imaging of liquid sodium contained inside an alloy jacket. Furthermore, challenges are identified to enhance the spatial and thermal resolutions in order to achieve more physically demanding imaging of the liquid metal thermal transport behaviors.

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