Perspective: Issues in CHF modeling - the need for new experiments

Journal Article · Tue Aug 01 04:00:00 EDT 1995 · Journal of Heat Transfer

DOI:https://doi.org/10.1115/1.2822614· OSTI ID:478456

Sadasivan, P; Unal, C; Nelson, R ^[1]

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1. Los Alamos National Lab., NM (United States)

Nucleate boiling and critical-heat-flux (CHF) phenomena have been studied extensively for several decades. However, a satisfactory mechanistic description remains elusive. Although the influences of some system parameters such as heater geometry, body forces, etc., have been elucidated, the influences of several others remain in dispute. In this paper, we present our perspective on the current state of CHF modeling. We list possible parameters that are relevant in the process and discuss the interactions among these parameters. The consequences of such interactions are also discussed. We focus on the simplest configuration-saturated pool boiling on flat heaters. Additional complexities such as orientation effects, flow effects, enhanced surfaces, etc., are not addressed We highlight specific areas on which we believe experimental efforts should focus to obtain improved mechanistic models of CHF. Experimental techniques used in previous studies are evaluated, and recommendations for new or modified techniques are discussed We believe CHF must be looked at in the boiling plane (q and {Delta}T) rather than merely as a single heat-flux point. Mechanistically, this leads us to view CHF as the limiting point of the nucleate boiling region rather than as an independent entity. Experimentally, this means that issues related to the high-heat-flux region must be studied and their effects on CHF investigated. 54 refs., 1 fig.

• Sponsoring Organization: USDOE
• OSTI ID: 478456
• Journal Information: Journal of Heat Transfer, Journal Name: Journal of Heat Transfer Journal Issue: 3 Vol. 117; ISSN 0022-1481; ISSN JHTRAO
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
CRITICAL HEAT FLUX
FLOW MODELS
NUCLEATE BOILING