Investigation of temperature fluctuation in loop heat pipe under acceleration fields

Based on the centrifugal machine system, a test apparatus was set up to investigate the operating characteristics of dual compensation chambers loop heat pipe (DCCLHP) under both gravity and acceleration fields. The ranges of the heat load and the magnitude of acceleration are 25-300 W and 3 g-9 g, respectively. The influences of different heat loads, acceleration directions and magnitudes on temperature fluctuations of loop heat pipe were analyzed. The results indicate that the effect of the acceleration can change the start mode and operating performance of the DCCLHP. The temperature fluctuation at the outlet of the condenser and even around the whole loop can be restrained or wakened. But the operating temperature of the evaporator is nearly the same under the same heat load conditions. The inherent flow instability of the gas-liquid two phase flow can be enhanced by the acceleration effect which reinforces this unstable flow in reverse. Furthermore, the instability of the heat leak from the evaporator to the compensation chamber is enhanced. In addition, the cooling effect of the condenser can weaken the temperature fluctuation of the condensing pipe line.