Fig. 1. The schematic diagram of heat transfer in heat pipe (color online)

Fig. 2. Schematics of heat transfer mechanisms of high-temperature heat pipes (color online)

Fig. 3. Geometry and mesh generation of high-temperature straight heat pipes

Fig. 4. The geometry and mesh generation of high-temperature bending heat pipes

Fig. 5. Mesh independence test of axial temperature of pipe wal (a) 0.5 s, (b) 1 s, (c) 1.5 s

Fig. 6. The schematic diagram of experimental apparatus for high-temperature heat pipe

Fig. 7. Photos of experimental apparatus for high-temperature heat pipe

Fig. 8. Photos of the high-temperature heat pipe and the thermocouple layout(a) Straight heat pipe, (b) Bending heat pipe

Fig. 9. Flow pattern and temperature profile for sodium heat pipe with wick region (color online)

Fig. 10. Diagram of flow field evolution in the first stage of the bent heat pipe

Fig. 11. Diagram of flow field evolution in the second stage of the bent heat pipe

Fig. 12. Diagram of flow field profile of the bent heat pipe under steady state

Fig. 13. Temperature profile of the straight heat pipe under steady state (color online)

Fig. 14. Temperature profile of the bending heat pipe under steady state (color online)