Research Issues on Two-Phase Loops for Space Applications
5 ADVANTAGES OF TWO-PHASE LOOPS FOR SPACECRAFT THERMAL CONTROL 5 TWO SUCCESSFUL IN-ORBIT EXPERIMENTS: TPX I & LHPFX 7 ESA’s Two-Phase eXperiment TPX I 7 Loop Heat Pipe Flight eXperiment LHPFX 9 DESIGN SUPPORTING THEORETICAL WORK 10 Background of Thermal-Gravitational Modelling and Scaling 10 Dimension Analysis & Similarity Considerations 10 Pressure Drop & Heat Transfer Equations for Annular Flow 13 FLOW PATTERN ISSUES 15 Flow Pattern or Flow Regime Mapping 15 Flow Pattern Mapping for Anti-Super-Gravity 16 CURRENT LOOP-RELATED R&D ACTIVITIES AT NLR 17 AMS-2 Thermal Control 17 CIMEX-3: NLR’s Versatile Two-Phase Loop Experiment 18
Second Law Analysis of a Gas-Liquid Absorption Film
This paper reports an analytical study of the second law in the case of gas absorption into a laminar falling viscous incompressible liquid film. Velocity, temperature, and concentration profiles are determined and used for the entropy generation calculation. Irreversibilities due to heat transfer, fluid friction, and coupling effects between heat and mass transfer are derived. The obtained results show that entropy generation is mainly due to coupling effects between heat and mass transfer near the gas-liquid interface. Total irreversibility is minimum at the diffusion film thickness. On approaching the liquid film thickness, entropy generation is mainly due to viscous irreversibility.
Investigations of dielectric gratings using electrodynamic models based on volume integral equations
Eigenmodes of planar and cylindrical dielectric gratings (DGs) and electromagnetic wave scattering from multiplayer DGs are investigated. The DG characteristics are calculated using numerical-analytical solution of integral equations (IEs).