Study of Temperature Effect on Cascade Characteristics of Nanofluidic Energy Absorption System

Abstract

Nanofluidic energy absorption system (NEAS) with cascade energy absorption characteristics can absorb energy on different levels simultaneously in one system, which greatly enriches its functions and applications. The pore structure and size distribution of porous media play a crucial role in the design and construction of cascade nanofluidic systems. In this paper, two cascade pore models were constructed using carbon nanotubes with different diameters, one was the model of two tubes with both one end immersed in water (DNEAS), and the other was the model of two tubes end to end, with the end of the big tube immersed in water (SNEAS). The effects of temperature-coupled pore size on the infiltration processes of water molecules into two models were investigated. The fitting correlations between critical pore size difference and temperature were established. The microscopic mechanism of temperature effect was illuminated. With the increase in temperature, systems displaying cascade characteristics transformed into a single-stage system without cascade characteristics. Due to the significant size effect of system temperature, the critical pore difference increased with both system temperature and the pore size. The research results expanded the basic database of cascade nanofluidic systems and provided guidance for the application design of cascade nanofluidic systems.

Study on the Influence of Loading Rate on the Cascade Characteristics of Nanofluidic Systems

“…In SNEAS, the infiltration process of the bottom tube is essentially identical to that of its corresponding single tube NEAS, while that of the top tube differs. The higher the loading rate, the greater the viscous dissipation of the system, which corresponds to an increase in the slope of the platform in the figure . The previous research findings indicate that the critical infiltration pressure of the SNEAS top tube is lower than that of its corresponding single tube NEAS under quasi-static conditions 43 because the number of hydrogen bonds decreases during the infiltration of water molecules into the SNEAS bottom tube. The smaller the hydrogen bond, the smaller the resistance of water molecules entering the CNT, and the lower the critical infiltration pressure.…”