Experimental study on dynamic characteristics of cylindrical horizontal axially rotating heat pipe

Abstract

• Rotating heat pipe can startup rapidly on normal conditions. • Temperature fluctuation can be inhibited by the rotation of rotating heat pipe. • Failure phenomenon caused by rotating speed variation is irreversible. • Occurrence of failure phenomenon is closely related to initial conditions. • High rotating speed can inhibit the failure phenomenon. Rotating heat pipe (RHP) has wide application prospects in the field of heat dissipation of rotating machinery. But researches on the dynamic characteristics of RHP are very few at present, which limits its application on real engineering. In this paper, the dynamic characteristics of RHP are investigated experimentally, including: startup characteristic, temperature fluctuation, and failure phenomenon. Results show that the rotating motion can obviously improve the performance of RHP during its startup process. Temperature fluctuation is obvious at 0 RPM, the fluctuation frequency increases and the fluctuation amplitude decreases with the increase of heating power. Rotation of RHP will obviously inhibit the temperature fluctuation. RHP will encounter failure phenomenon. Failure phenomenon is prone to occur under low filling ratio, low cooling temperature, and high heating power. Low rotating speed is easy to induce failure phenomenon and high rotating speed can restrain failure phenomenon. Increasing filling ratio can effectively inhibit failure. There are two inertial effects on failure phenomenon: the irreversibility of failure phenomenon caused by change of rotating speed and the hysteresis of the influence of cooling temperature variation on failure phenomenon. The dynamic performance of RHP is influenced by the inertial effects, the intrinsic mechanism is non-linear.