Thermo-acoustic study of transformer oils through ultrasonic technique

ABSTARCT

Study of two unused transformer oils was carried out by determining the thermo-acoustical parameters employing ultrasonic interferometer. The two transformer oils studied were of the year 1997 and 2017 make. The density measurement was carried out on the two oil samples at varied temperatures. The ultrasonic velocity for two different transformer oil samples in the temperature range of ambient to 343 K was measured for multiple frequencies. The measured ultrasonic velocity was used to calculate the thermo-acoustic parameters like adiabatic compressibility (β), intermolecular free length (L_f) and acoustic impedance (Z). The thermal conductivity variation with temperature of the oils was determined. The determined and observed parameters of the oil samples are thoroughly deliberated in this paper.

Keywords:

• density
• thermal conductivity
• thermo-acoustic parameters
• transformer oils
• ultrasonic interferometer