Distinctive Features of Heat Transfer During the Cooling of the Working Section by a Dispersed Flow

2021 ◽  
Author(s):  
S. V. Mirnov ◽  
A. N. Varava ◽  
A. V. Vertkov ◽  
A. V. Dedov ◽  
A. V. Zakharenkov ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Dispersed Flow ◽  
Distinctive Features ◽  
Working Section

RBHT Steam Cooling and Droplet Injection Pre-Test Analysis Using COBRA-TF

2001 ◽  
Author(s):  
C. Frepoli ◽  
A. J. Ireland ◽  
L. E. Hochreiter ◽  
F. B. Cheung
Keyword(s):  
Heat Transfer ◽  
Local Heat Transfer ◽  
Injection System ◽  
Test Facility ◽  
Film Boiling ◽  
Two Phase ◽  
Field Representation ◽  
Dispersed Flow ◽  
Spacer Grids ◽  
Flow Film Boiling

Abstract The droplet injection experiments to be performed in a 7 × 7 rod bundle heat transfer test facility are being simulated using an advanced thermal hydraulics computer code called COBRA-TF. A current version of the code, which provides a three-dimensional, two-fluid, three-field representation of the two-phase flow, is modified to facilitate the simulation of the droplet field produced by the injection system in the test facility. The liquid phase is split into a continuous liquid field and droplet field where a separate momentum and mass equation is solved for each field, with the effects of spacer grids being properly accounted for. Pre-test analyses using the modified COBRA-TF code have been conducted for different injection conditions. Results indicate that there are specific ranges of conditions that can be simulated within the facility constraints to provide for validation of the dispersed flow film boiling models. The numerical results also show important effects of the spacer grids on the local heat transfer in the dispersed flow film boiling regime.

Heat Transfer to Steam-Water Annular Dispersed Flow in Vertical Annulus

1971 ◽  
Vol 8 (7) ◽  
pp. 400-405
Author(s):  
Ichiro IKEMOTO ◽  
Masaharu TAKAYASU ◽  
Nobuyuki UENO ◽  
Itaru MICHIYOSHI
Keyword(s):  
Heat Transfer ◽  
Dispersed Flow ◽  
Vertical Annulus

An Analysis of Heat Transfer to Axial Dispersed Flow between Rod Bundles under Reactor Emergency Cooling Conditions

1980 ◽  
Vol 102 (3) ◽  
pp. 508-512 ◽  
Author(s):  
S. Wong ◽  
L. E. Hochreiter
Keyword(s):  
Heat Transfer ◽  
Diameter Ratio ◽  
Circular Pipe ◽  
Rod Bundles ◽  
Dispersed Flow ◽  
Rod Bundle ◽  
Cooling Conditions ◽  
Flow Heat ◽  
Square Array ◽  
The Heat Transfer Coefficient

Analysis is carried out for dispersed flow heat transfer under reactor emergency cooling conditions. The present formulation explicitly reveals an extra dependence of the heat transfer coefficient and Nusselt number on the mean vapor temperature for droplet dispersed flow which is not found in single phase flow heat transfer. The heat transfer results obtained from three different geometries—an infinite square array of cylindrical rods, an annulus and a circular pipe—are compared; all have the same hydraulic diameter. It is found that, within the framework of the present analysis, results for the annulus and the rod bundles agree well when the pitch-to-diameter ratio is 1.5 or greater. The circular pipe is in general a poor approximation for rod bundle geometries except at a pitch-to-diameter ratio of about 1.3 which is typical of present day light water reactor fuel assemblies.

Distinctive features of heat transfer in the region of a gas curtain formed on injection of extraneous gas

2010 ◽  
Vol 45 (4) ◽  
pp. 559-565 ◽  
Author(s):  
A. I. Leont’yev ◽  
V. G. Lushchik ◽  
A. E. Yakubenko
Keyword(s):  
Heat Transfer ◽  
Distinctive Features

Temperature measurements in a hypersonic gun tunnel using heat-transfer methods

1967 ◽  
Vol 27 (3) ◽  
pp. 503-512 ◽  
Author(s):  
B. E. Edney
Keyword(s):  
Thin Film ◽  
Heat Transfer ◽  
Mach Number ◽  
Heat Losses ◽  
Transfer Rates ◽  
Gun Barrel ◽  
Compression Cycle ◽  
Initial Shock ◽  
Working Section ◽  
Good Agreement

The theory of Fay & Riddell (1958) is used to calculate stagnation temperatures from stagnation-point heat-transfer rates measured in the working section of a hypersonic gun tunnel at a Mach number of 9·8. Measurements using both thin-film gauges and calorimeters are described. The temperatures measured using this technique are found to be lower than predicted by Lemcke (1962) from measurements of shock strengths and final pressures in the gun barrel. This discrepancy is attributed to heat losses in the barrel during the initial shock compression cycle. A simple theory is developed to take into account these losses. There is good agreement between this theory and the experimental results.

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