Velocity Field in Turbulent Subcooled Boiling Flow

Abstract

The velocity field was measured in turbulent subcooled boiling flow of Refrigerant-113 through a vertical annular channel whose inner wall was heated. A two-component laser Doppler velocimeter was used. Measurements are reported in the boiling layer adjacent to the inner wall as well as in the outer all-liquid layer for two fluid mass velocities and four wall heat fluxes. The turbulence was found to be inhomogeneous and anisotropic and the turbulent kinetic energy significantly higher than in single-phase liquid flow at the same mass velocity. A marked shift toward the inner wall was observed of the zero location of the axial Reynolds shear stress in the liquid phase, and the magnitude of the shear stress increased sharply close to the inner wall. The near-wall liquid velocity field was quite different from that in single-phase liquid flow at a similar Reynolds number. Comparison of the measurements with the predictions of a three-dimensional two-fluid model of turbulent subcooled boiling flow show reasonably good agreement for some quantities and a need for further development of certain aspects of the model.

Stereo-PIV measurements of vapor-induced flow modifications in confined jet impingement boiling

“…In an extension of this study, Roy et al (1997) used laser Doppler velocimetry (LDV) to include liquid velocity measurements within the bubbly boundary layer close to the inner heated wall. The production of turbulence kinetic energy close to the wall increased due to high Reynolds shear stresses in these regions induced by boiling.…”

CIPS Validation Data Plan

“…Phenomena investigated Scaling Bertel et al (2001) Interfacial area in SFB 1 (1 atm) Garnier et al (2001) Local measurements 1 (R12) Kang et al (2002) Vapor phase measurements SFB 1 (R113) Warrier et al (2002) Interfacial heat transfer 1 (low P) Roy et al (1992Roy et al ( , 1997 Turbulence, void fraction 1 (R133) Chen et al (2003) Bubble coalescence 1 (1 atm) Yeoh et al (2004) Bubble departure, bubbly flow 1 (1-2 atm) Okawa et al (2005a,b) Bubble slide 1 (1 atm) Maurus et al (2006) Bubble; boundary layer 1 (horiz.) Bang et al (2004) Visual bubble 1 (R134a) Situ et al (2004a,b) Bubble dynamics 1 (1 atm) Unal (1976) Bubble growth 3 (full P) Chang et al (2002) Wall bubble 1 (R134a) Basu et al (2005) Wall heat partitioning in SFB 1 (low P) Basu et al (2002) Boiling onset, nucleation site density 1 (low P) Nucleation site …”

CASL Validation Data: An Initial Review

“…However, the data are typically measured in bubbly flow regime, corresponding to fully-developed nucleate boiling, and not addressing the subcooled boiling flow pattern. Data exist for simplegeometry channel, but not in subcooled boiling regime "Soft" wall (condensing bubble dome) effect on turbulence Roy (1992Roy ( , 1997 Situ et al (2004) Maurus & Sattelmayer (2006) Void fraction distribution along and across the channel (fuel assembly) Bartolomei & Chanturiya (1967) Bertel et al (2001 Garnier et al (2001) Yeoh & Tu ( , 2005a& Tu ( , 2005b Tu et al 2005Thorncroft et al (1998( ) Basu et al (2005a Kumar et al (2003) Hibiki et al (2003) Warrier et al (2002) DEBORA facility TOPFLOW facility Nucleation pattern Basu et al (2002 Typically, parameters representing a "mesoscale" effect cannot be directly measured in a boiling or flow boiling experiments, especially under narrow-channel, high-pressure, high-temperature conditions characteristic of a PWR core. Thus such "mesoscale" data are derived from measurable (macroscale) information using a model.…”