Forced convection film boiling drag and heat transfer of a wedge

Conference · Mon Jan 01 04:00:00 EST 1990

DOI:https://doi.org/10.2514/6.1990-1724· OSTI ID:7005635

Chappidi, P R; Pasamehmetoglu, K O ^[1]; Gunnerson, F S ^[2]

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1. Los Alamos National Lab., NM (USA)
2. University of Central Florida, Orlando, FL (USA). Dept. of Mechanical Engineering

Laminar forced convection film boiling flow on a wedge is analyzed considering the streamwise pressure gradient imposed on the flow and the streamwise buoyancy force (important because of the large density difference between the vapor and liquid) acting on the vapor film. A two-phase boundary layer model is proposed, and the local similarity concept is applied to obtain an approximate solution of the governing equations. Parametric trends in this analysis show that, for a water-steam system at atmospheric pressure considered within this study, the density difference between the vapor and liquid is large enough. As a result, both the streamwise pressure gradient and the buoyancy force exert strong influence on the vapor flow dynamics. Wall skin friction results display a strong dependency on the streamwise buoyancy force driving the vapor film and the external pressure gradient. Previously observed skin friction bucket'' type phenomena with increased heating of the wedge are possible when the buoyancy force is small or negligible. Adverse streamwise buoyancy force action on the vapor film, which is the case on the lower surface of a horizontally aligned wedge, may cause vapor flow separation. In contrast to wall skin friction dependency, the wall heat-transfer parameter shows a secondary dependence on the streamwise pressure gradient and the buoyancy force. 16 refs., 9 figs., 3 tabs.

• Research Organization: Los Alamos National Lab., NM (USA)
• Sponsoring Organization: DOD
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 7005635
• Report Number(s): LA-UR-90-1374; CONF-900619--4; ON: DE90010611
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420400* -- Engineering-- Heat Transfer & Fluid Flow
640410 -- Fluid Physics-- General Fluid Dynamics
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALGORITHMS
BOUNDARY CONDITIONS
BOUNDARY LAYERS
CONVECTION
DRAG
ENERGY TRANSFER
FLUID FLOW
HEAT TRANSFER
LAMINAR FLOW
LAYERS
MASS TRANSFER
MATHEMATICAL LOGIC
PRESSURE GRADIENTS
TWO-PHASE FLOW