scholarly journals Discussion: “Critical Heat Flux Measurements in a 16-Rod Simulation of a BWR Fuel Assembly” (Israel, S., Casterline, J., and Matzner, B., 1969, ASME J. Heat Transfer, 91, pp. 355–361)

1969 ◽  
Vol 91 (3) ◽  
pp. 361-362
Author(s):  
F. A. Schraub
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Fuel Assembly ◽  
Critical Heat Flux ◽  
Flux Measurements

Critical Heat Flux Measurements in a 16-Rod Simulation of a BWR Fuel Assembly

1969 ◽  
Vol 91 (3) ◽  
pp. 355-361 ◽  
Author(s):  
S. Israel ◽  
J. Casterline ◽  
B. Matzner
Keyword(s):  
Heat Flux ◽  
Fuel Assembly ◽  
Critical Heat Flux ◽  
Power Distribution ◽  
Test Section ◽  
Flow Boiling ◽  
Forced Flow ◽  
Flux Data ◽  
Flux Measurements ◽  
Square Array

Critical heat flux data were obtained for forced flow boiling in a 16-rod test section arranged in a square array. The tests were performed at 1000 psia and used a radial power distribution which represented the region about the hot corner in a BWR fuel assembly. The results are lower than data obtained in a 9-rod square array, having a uniform power distribution, based on the average bundle exit quality. These two sets of data are in fair agreement when compared on the basis of the highest subchannel exit quality. Comparisons of different sets of data show the effects of different rod spacers and bundle misalignment on the critical heat flux.

scholarly journals Predicting Critical Heat Flux With Multiphase CFD: 4 Years in the Making

2017 ◽  
Author(s):  
Emilio Baglietto ◽  
Etienne Demarly ◽  
Ravikishore Kommajosyula
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Critical Heat Flux ◽  
Bubble Dynamics ◽  
Flow Boiling ◽  
Heated Surface ◽  
Force Balance ◽  
Modeling Framework ◽  
Lift Off ◽  
Limiting Condition

Advancement in the experimental techniques have brought new insights into the microscale boiling phenomena, and provide the base for a new physical interpretation of flow boiling heat transfer. A new modeling framework in Computational Fluid Dynamics has been assembled at MIT, and aims at introducing all necessary mechanisms, and explicitly tracks: (1) the size and dynamics of the bubbles on the surface; (2) the amount of microlayer and dry area under each bubble; (3) the amount of surface area influenced by sliding bubbles; (4) the quenching of the boiling surface following a bubble departure and (5) the statistical bubble interaction on the surface. The preliminary assessment of the new framework is used to further extend the portability of the model through an improved formulation of the force balance models for bubble departure and lift-off. Starting from this improved representation at the wall, the work concentrates on the bubble dynamics and dry spot quantification on the heated surface, which governs the Critical Heat Flux (CHF) limit. A new proposition is brought forward, where Critical Heat Flux is a natural limiting condition for the heat flux partitioning on the boiling surface. The first principle based CHF is qualitatively demonstrated, and has the potential to deliver a radically new simulation technique to support the design of advanced heat transfer systems.

Sign in / Sign up

Export Citation Format

Share Document