Convective Heat Transfer Coefficients for Near-Horizontal Two-Phase Flow of Nitrogen and Hydrogen at Low Mass and Heat Flux

Published

November 1, 2001

Author(s)

N T. Van Dresar, James D. Siegwarth, M M. Hasan

Abstract

Correlations for convective heat transfer coefficients are reported for two-phase flow of nitrogen and hydrogen under low mass and heat flux conditions. The range of flow rates, heat flux and tube diameter are representative of thermodynamic vent systems (TVSs) planned for propellant tank pressure control in spacecraft operating over long durations in microgravity environments. Experiments were conducted in normal gravity with a 1.5 upflow configuration. The Nusselt number exhibits peak values near transition from laminar to turbulent flow based on the vapor Reynolds number. This transition closely coincides with a flow pattern transition from plug to slug flow. The Nusselt number was correlated using components of the Martinelli parameter and a liquid-only Froude number. Separate correlating equations were fitted to the laminar liquid/laminar vapor and laminar liquid/turbulent vapor flow data. The correlations give root-mean-squared prediction errors within 15%.

Citation

Cryogenics

Volume

41

Issue

No. 11-12

Pub Type

Journals

Keywords

heat transfer, space cryogenics, two-phase flow

Citation

Van Dresar, N. , Siegwarth, J. and Hasan, M. (2001), Convective Heat Transfer Coefficients for Near-Horizontal Two-Phase Flow of Nitrogen and Hydrogen at Low Mass and Heat Flux, Cryogenics (Accessed April 25, 2025)