VOID FRACTION AND FRICTIONAL PRESSURE DROP IN INVERTED FILM BOILING HYDROGEN

J. Pasch
University of Florida,Gainsville, USA

S. Anghaie
Department of Nuclear Engineering Sciences, Innovative Nuclear Space Power and Propulsion Institute University of Florida Gainesville, FL 32611, U.S.A.

DOI: 10.1615/IHTC13.p28.20
12 pages

Resumo

Measurements from steady state inverted annular film boiling of hydrogen flowing upwards in a round, highly heated tube are used to model void fraction and frictional pressure drop. A one-dimensional separated flow model is developed to calculate the void fraction and the contribution of frictional losses to the overall pressure drop. The effect of mass flux and heat flux on void fraction and frictional losses are discussed. Results are analysed in terms of test system conditions, flow parameters, and modelling assumptions. It is shown that void fraction is independent of mass flux, and directly related to heat flux. Momentum loss due to friction is determined to be generally 3-10% of the total pressure loss, and is a function of mass flux. The heat flux dependence is found to be a function of mass flux. In 20 runs, the range of test parameters are: 188 kPa ≤ P_i ≤ 498 kPa, 575 kg/m²·s ≤ m ≤ 1653 kg/m²·s, 376 kW/m² ≤ q″ ≤ 1651 kW/m².