Measurement of speed of sound and thermal diffusivity of ethyl heptanoate using light scattering method

Fatty acid ethyl esters are the main components of biodiesels , the increasing use of biodiesels requires the study of thermophysical properties . This paper measured the speed of sound and the thermal diffusivity in liquid ethyl heptanoate from 293.15 K to 483.15 K and up to 10 MPa using light scattering method. The relative expanded uncertainties in the speed of sound and the thermal diffusivity are estimated to be less than 0.5% and 3.0% with coverage factor of k equaling 2. The data were also fitted into polynomials. For the speed of sound, the AADs between the experimental and calculated values are 0.21% in saturated liquid and 0.21% in compressed liquid. For the thermal diffusivity , the AADs are 0.46% in saturated liquid and 0.40% in compressed liquid. The temperature and pressure influence on the speed of sound and the thermal diffusivity were also analyzed.