Prediction of annular two-phase flow in microgravity and earth-normal gravity

Conference · Tue Dec 31 04:00:00 EST 1996

OSTI ID:484978

Reinarts, T R ^[1]; Ungar, E K ^[2]

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1. Mainstream Engineering Corp., Rockledge, FL (United States)
2. NASA/Johnson Space Center, Houston, TX (United States)

Annular flow occurs in zero-g over a much broader range of conditions than in Earth-normal gravity (one-g). In horizontal tubing at one-g, annular flow is typically limited to the case of small tubing (where surface tension overwhelms the gravity effects) and the case of high speed vapor flow (where inertial effects overwhelm the gravity effects). Data obtained from one-g experiments in these conditions can be applied to the case of zero-g two-phase flow, but care must be taken that they are applied correctly. The analysis here utilizes the available, validated data-base of annular zero-g data and accompanying (where available) pure annular one-g flow. This data base includes ammonia, dichlordifluoromethane (R12), air/water, air/water-glycerin, and air/water Zonyl FSP in a variety of tube inside diameters. The first step is an analysis of the flow regime data and the flow regime prediction models for annular flow. The applicability and validity of each model is analyzed. The pressure drop data are then presented, analyzed, and compared with the available predictive models. A comparison of one-g and microgravity pressure drop is made, and the limits of using small ID tubing and high speed vapor flows to simulate micro gravity conditions are given.

• OSTI ID: 484978
• Report Number(s): CONF-960815--
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
ANNULAR SPACE
DATA ANALYSIS
FLOW MODELS
GRAVITATION
PRESSURE DROP
TEMPERATURE CONTROL
TWO-PHASE FLOW
WORKING FLUIDS