@inproceedings{c5188d037fec4bca8ba1dbf186601c20,
title = "Observations of flow instability in a heated narrow vertical slot in the ucb ciet facility",
abstract = "Flow instability in a heated narrow vertical slot has been observed within the annular heating element of the Compact Integral Effects Test (CIET 1.0) facility. The heating element is composed of an electrical resistance heated outer tube, an electrically isolated inner tube, and a heat transfer oil flowing within the annular slot of the assembly. Dowtherm A heat transfer oil is used in the CIET 1.0 facility to simulate high-Temperature fluoride salt, allowing CIET 1.0 to take advantage of reduced height, flow area, system temperature, and system input power due to the favorable scaling of oil versus salt. The heater element was scaled to replicate scaled coolant residence time and pressure drop of a pebble-bed core. Significant fluid temperature oscillations (approximate average amplitude of 5°C) at the heating element outlet during heated tests provided the first indication of unexpected behavior with the annular heater. Flow instability was then confirmed by measurement of anomalous, shifting surface temperature distributions occurring azimuthally around the heating element's outer circumference. Investigation of the concentricity of the heating element's annular slot geometry was undertaken to further investigate the presence of significant flow instability observed within and at the outlet of the CIET 1.0 annular heating element. Conclusions of this study identify the potential causes and performance impacts of flow instability in narrow heated slots, which are relevant to plate-Type fuel designs. Implications for the design of full-scale fluoride salt systems are discussed.",
author = "Kendrick, {J. C.} and Novak, {A. J.} and Poresky, {C. M.} and N. Zweibaum and Peterson, {P. F.}",
year = "2016",
language = "English (US)",
series = "International Congress on Advances in Nuclear Power Plants, ICAPP 2016",
publisher = "American Nuclear Society",
pages = "168--174",
booktitle = "International Congress on Advances in Nuclear Power Plants, ICAPP 2016",
address = "United States",
note = "2016 International Congress on Advances in Nuclear Power Plants, ICAPP 2016 ; Conference date: 17-04-2016 Through 20-04-2016",
}