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In this study, hydrofoil ribs having NACA 2412 profile were mounted in a novel way at all walls of microchannel heat sink with various configurations to improve its thermo-hydraulic characteristics. The various configurations include comparison between staggered and aligned arrangements, and the variation of rib spacing between two hydrofoils (Sr = 200-600 µm) at a constant cord length (Cr = 400 µm). The performance of various configurations were compared with each other and with smooth channel using parameters like friction factor (f), Nusselt number (Nu), and overall performance is determined by thermal enhancement factor (η). The results showed that the best performance is achieved by the configuration where rib spacing became equal to cord length (Sr = 400 µm). Moreover, staggered configuration performed better than aligned configuration.

A strain-rate-sensitive polyurethane elastomer is numerically investigated to reveal impact behaviors and analyze the inputted strain energy dissipation features with concerned rate dependencies. In view of the amorphous structure of elastomers, a thermo-mechanical model is developed via relating the macro-mechanical behaviors to micro-structural changes through molecular transitions and two distinct flow activations with each possessing a unique activation energy. Under large straining, detangling of molecular chains and networks through sliding is found to produce serious frictional effects resulting in instantaneous heat generation and temperature rise. To incorporate these heat-effected issues, an instantaneous temperature rise is calculated at each macro-level material point to ascertain the localized changes in the associated mechanical response. The overall perspectives of the dynamic mechanical behavior including visco-elastic large deformation, rate dependent yielding, thermal softening, flow at plateau stress, and strain hardening are found well captured. Investigations are extended for the material recoverability and accordingly, strain energy absorptions are clarified. Finally, a power law function is proposed for designing the energy absorption relation to the applied loading rate.

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It has been long recognized that using the conventional production logging tool in combination with the electrical probes measurement for water holdup can resolve the source identification of water inside the borehole. The source of water for single layer reservoir can be identified easily and can be complex for borehole involving multilayers and multiphase. The current limitations with the conventional production logging tool is that it covers the quantitative measurements inside borehole and to some extent qualitative measurement behind casing e.g. temperature profile.