Abstract: In view of foaming in the filtration cycle of No. 65 aviation coolant, the foaming propensity of the aviation coolant was explored. According to the SH / T 0066-2002 (Engine coolant foam tendency measurement method), the coolant foam tendency tester was used to evaluate the tendency of the coolant foaming and the water glycol fluids control test was used as a reference. The results showed that the aviation coolant had a higher foaming tendency in the case of low temperature and long cycle time, and the foaming tendency was reduced to some extent with the increase of temperature and the shortening of the cycle time. It is concluded that the foaming in the filtration cycle of aviation coolant is caused by the added additives.

Key words: NNo.65 aviation coolant, foaming, ropensity, water glycol fluids