Application of Additively Manufactured Pentamode Metamaterials in Sodium/Inconel 718 Heat Pipes.

Longfei Hu,Xiaoguang Luo,Bangcheng Ai,Ketian Shi,Chao Liu,Jijun Yu

doi:10.3390/ma14113016

Abstract

In this study, pentamode metamaterials were proposed for thermal stress accommodation of alkali metal heat pipes. Sodium/Inconel 718 heat pipes with and without pentamode metamaterial reinforcement were designed and fabricated. Then, these heat pipes were characterized by startup tests and thermal response simulations. It was found that pentamode metamaterial reinforcement did not affect the startup properties of sodium/Inconel 718 heat pipes. At 650–950 °C heating, there was a successful startup of heat pipes with and without pentamode metamaterial reinforcement, displaying uniform temperature distributions. A further simulation indicated that pentamode metamaterials could accommodate thermal stresses in sodium/Inconel 718 heat pipes. With pentamode metamaterial reinforcement, stresses in the heat pipes decreased from 12.9–62.1 to 10.2–52.4 MPa. As a result, sodium/Inconel 718 heat pipes could be used more confidently. This work was instructive for the engineering application of alkali metal heat pipes.

Highlights

Power throughputs of 15 kW/cm2 were possible for sodium heat pipes operated at 880 ◦ C [5]
HP3 and HP4 were selected for the thermal response simulation because of their identical sodium charging ratio
There was a successful startup of sodium/Inconel 718 heat pipes in the startup tests

Summary

Introduction

Heat pipes, combining the advantages of high conductivity and inherent safety, are attractive devices for thermal management of hot structures, such as large-scale heat exchangers, thermal protection of hypersonic vehicles, heat radiation of space reactors and so on [1,2,3,4]. For these applications, alkali metal heat pipes were feasible for source temperatures above 600 ◦ C. The feasibility of alkali metal heat pipes has been demonstrated by various researchers Power throughputs of 15 kW/cm were possible for sodium heat pipes operated at 880 ◦ C [5].

Objectives

Methods

Results

Discussion

Conclusion