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Cavitation, the study of formation, growth, and collapse of vapor cavities in the coolant jacket adjacent to diesel engine cylinder liners is an area of concern for diesel engine builders and users. Prior experimental work provides insight into parameters such as temperature and pressure. A commonly used bench test has been found not to correlate well with field testing. Also, field testing is very time consuming and costly. The 250 hour engine dynamometer coolant test in the industry costs over $60,000. Therefore, use of mathematical models for sorting out coolants is used, to study effects of coolant properties such as viscosity and surface tension on liner cavitation. Jet velocity at the time of implosion of the bubble is considered as a mechanism to quantify cavitation damage potential near a rigid wall. A model calculating jet velocity at the time of bubble collapse near a finite plate is determined using a commercial boundary element code, 2DynaFS.

Fluid cavitation corrosion can cause severe damage and problems in many practical applications. A collapsing bubble produces pressure and thermal shock waves, and microjets. These intense local forces will erode material in the proximity of the collapsing bubble. The intensity of the collapsing bubble is heavily dependent on the physical and thermodynamic properties of the cavitating fluid medium. An experimental study of the effect of various physical and fluid thermodynamic properties of the fluid has been conducted utilizing an ultrasonic cavitation generator and a real time cavitation intensity measuring method that had been developed earlier by the author and described in reference [1]*. Tests have been conducted at room and elevated temperatures. A test matrix with fluids that have additives to modify certain physical characteristics of the fluid was established. The physical properties were either measured or calculated.

Several ultrasonic bench rigs are widely used in the engine coolant industry for cavitation corrosion tests. These tests are focused on the qualification of coolants formulated to minimize cavitation corrosion. Standardized metal test “buttons” of different materials are used for that purpose. Traditionally these cavitation corrosions tests are run for a specified period of time. At the end of the test the amount of mass removed from coupons due to cavitation is a direct reflection of the cavitation corrosion performance of the additive. However, results can show wide scatter and inconsistencies depending on the ultrasonic probe manufacturer, testing lab, horn type, dial setting level and probe instability. Therefore, a way of quantifying the cavitation intensity of these various designs was clearly called for to establish a standardized test and recommendation to be utilized across the coolant testing community.