THE CONDENSATE DROPLETS CENTERING IN THE VAPOUR CHANNEL OF SHORT LOW TEMPERATURE RANGE HEAT PIPES AT HIGH HEAT LOADS
The article presents results of experimental studies of the process of condensate microdroplets centering contained in the moving moist vapour in the vapour channel of short heat pipes (HPs) for large thermal loads. In the upper cover a HPs condensation surface is formed, the capacitive sensors are installed on the diametrical line, where electrodes form three capacitors located at different distances from the longitudinal axis of the vapour channel and called external, middle and internal capacitors. Increasing heat load and beginning the boil in the evaporator a large amount of moist vapour occurs in the vapour channel of HP the pressure pulsation with frequency of 400-500 Hz and amplitude up to 1∙104Pa. These pulsations affect the moving of the inertial droplets subsystem of the vapour and due to the heterogeneity of the velocity profile around the particle flow in the vapour channel at the diameter of microdroplets occurs transverse force, called the Saffman force and shear microdroplets to the center of vapour channel. Using installed in the top cover capacitors we can record the radial displacement of the condensable microdroplets. We measure frequency of the radial waves ripple movable in the radial direction to the center of the film thickness maximums of condensate of the working fluid depending on the thermal load at the HPs evaporator.