Effect of Air Content on the Internal Fluid Characteristics of Liquid Floated Gyro

The liquid floated gyro (LFG) is an inertial instrument widely used in aviation, aerospace, navigation, and other high-tech fields, with the advantages of high accuracy and good in-orbit reliability. The filling of internal floating oil is a key process in the manufacture of LFG, however, due to the limitation of technology level, environmental conditions, and other factors, the floating oil may be mixed with a certain amount of air, which affects the rheological characteristics of the oil, thus leading to the accuracy drift of the gyro instrument. Therefore, this paper analyzes the effect of air content on the fluid characteristics of the gyro oil by using the computational fluid dynamics method. The results show that the air content has a significant effect on the oil dynamics: when the air content increases from 0% to 3%, the average flow velocity of the oil decreases by 4.15%, and the viscous interference torque increases by 0.02%, which reduces the stability of the instrument accuracy to a certain extent, so the generation of air bubbles should be avoided or necessary measures should be taken to remove air bubbles during the oil filling process.