Comprehensive Electrical Evaluation of Polyalphaolefin Dielectric Coolant

A review of the state-of-the-art electrification and electrical breakdown phenomena in flowing dielectric liquids used for both heat transfer and electrical insulation has shown that the existing test methods are not capable of identifying the circumstances in which large amounts of charge can be generated or large depressions of electric strength of these liquids can be experienced in the hydraulic circuit. The objective of the present proposal is to develop a new test method for comprehensive evaluation of the electrical properties of polyalphaolefin (PAO) dielectric coolant by including synergism of different factors adjustable to the performance parameters of the Navy applications. The proposed circulating type tester shall examine the effects of (1) temperature, moisture, contamination, and charging tendency of a liquid sample, and (2) constructional materials of a fluid-assembly, superimposed AC and DC electric fields, and geometrical and hydrodynamic parameters of a flow in the Navy equipment. Moreover, we propose a new electro-separation technique which, by applying a non-uniform AC electric field to flowing PAO dielectric coolant, will exploit the electric-field-induced aggregation and dielectrophoresis to remove contaminants from the flow and, thereby, to increase liquid's breakdown strength.