ESTIMATION OF THE SHARMA CONSTANT AND THERMOACOUSTIC PROPERTIES OF VEGETABLE-OILS

The density and volume of four Indian edible vegetable oils, sunflower, rice bran, groundnut and coconut, and one Indian nonedible oil, castor oil, have been experimentally determined. The values obtained were used to estimate the volume expansivity alpha, hence the thermoacoustic parameters, such as the Sharma constant S-0, the isochoric temperature coefficient of internal pressure [dlnPi/dlnT](V), the isochoric temperature coefficient of volume expansion [dlna/dlnT]V-,V- reduced volume ($) over tilde V, reduced compressibility ($) over tilde beta and the Huggins parameter F. The results obtained show that the Sharma constant S-0 has the same characteristic value of 1.11 +/- 0.01 for the five oils, thus establishing the constancy of the Sharma parameter. All the other parameters are of the expected order of magnitude; however, in all cases there is a uniform deviation at 293 degrees K, which can be attributed to the behavior of density and volume at this temperature.