Damping properties of a two-phase mixture of transformer oil with gas bubbles

Abstract

In recent years, gas–liquid media are of interest due to their damping properties, which may be sufficient to prevent the mechanical destruction of the oil-filled equipment in consequence of electrical breakdown. For this purpose, an experimental installation was created, where the classical method of electric explosion of a wire is used to study the damping properties of a gas–liquid mixture. Microbubbles with a diameter of 1 mm and 0.5 mm were generated with a tangential air supply in a narrowing part of the Venturi tube or using a Laskin nozzle, respectively. Studies have shown that when the oil is aerated with 1 mm bubbles, final waves amplitude, decreases almost by 5 times, and when gassing with 0.5 mm bubbles the amplitude, decreases by more than 10 times. The attenuation of the amplitude of the pressure wave by a factor of the Euler number e in pure oil occurs in ≈ 7 ms, the bubbles with a diameter of ≈ 1 mm lead to an attenuation in ≈ 5 ms, and the bubbles with diameter of ≈ 0.5 mm in ≈ 2 ms.