Dynamic response of a liquid-vapor interface during flow film boiling from a sphere

Journal Article · Sun Nov 01 04:00:00 EST 1987 · Journal of Heat Transfer (Transcations of the ASME (American Society of Mechanical Engineers), Series C); (United States)

DOI:https://doi.org/10.1115/1.3248183· OSTI ID:5344498

Orozco, J; Stellman, R; Poulikakos, D ^[1]

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1. Univ. of Illinois, Chicago (USA)

Film boiling is the mode if boiling during which the hot surface is separated from the vaporizing liquid by a nearly continuous film vapor. Film boiling is usually considered a very undesirable boiling regime since it is a relatively quiet and inefficient mode of heat transfer, particularly as compared to nucleate boiling. It is customary to analyze the two-phase flow regime of laminar flow film boiling by assuming the two-phase flow regime of laminar flow film boiling by assuming an idealized vapor film flow characterized by a smooth liquid-vapor interface. However, during stable flow film boiling, the wavy nature of the liquid-vapor interface and its role in local heat and mass transport have been largely ignored. The vapor interface is rarely stationary. Interfacial waves may substantially augment the heat transfer rates throughout the layer. The present analysis treats stagnation point flow film boiling on a sphere immersed in a subcooled liquid. The effect of system parameters on the dynamic behavior of the liquid-vapor interface as well as the response to step changes in the temperature and velocity fields are investigated. The study corrects and extends the theoretical analysis previously developed by Sheppard and Bradfield (1972). The new theoretical model not only allows for the influence of liquid velocity, vapor superheat, and liquid subcooling on the wavy nature of the liquid-vapor interface, but it also sheds some light on the response of the system of perturbations in heat flux and superheat and into the conditions leading toward instances of liquid-solid contact during stable flow film boiling.

• OSTI ID: 5344498
• Journal Information: Journal of Heat Transfer (Transcations of the ASME (American Society of Mechanical Engineers), Series C); (United States), Journal Name: Journal of Heat Transfer (Transcations of the ASME (American Society of Mechanical Engineers), Series C); (United States) Vol. 109:4; ISSN 0022-1481; ISSN JHTRA
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420400* -- Engineering-- Heat Transfer & Fluid Flow
BOILING
BOUNDARY CONDITIONS
COOLING
FILM BOILING
FLUID FLOW
HEATING
LAMINAR FLOW
MOVING-BOUNDARY CONDITIONS
PHASE TRANSFORMATIONS
SPHERES
SUBCOOLING
SUPERHEATING
TEMPERATURE DISTRIBUTION
VELOCITY