Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : November 07, 2019 - November 08, 2019
In an emulsion emulsified and mixed with water and fuel oil, the fuel that causes the micro-explosion when the superheat limit of water is exceeded during combustion is called emulsified fuel. One of the biggest problems for putting it into practical use is emulsion instability. It is important to prevent the malfunction of an internal combustion engine and get the effect of exhaust gas reduction. The stability of emulsion fuel is obtained by preventing a creaming in which the water droplets of dispersed phase settle and stratify due to the density difference from the fuel oil of the continuous phase. The settling shear velocity is decided by the droplet size. In this study, we focused on the measurement using the ultrasonic waves that reflected an attenuated at the interface of the medium with different acoustic impedance. In this report, we produced 10 %, 20 %, 30 % water-vegetable oil emulsified fuel with a Taylor-Couette reactor and measured it utilizing ultrasonic echo attenuation and compared it with ultrasonic velocity profiler. As a result, the ultrasonic attenuation coefficient tended to increase as the inner cylinder rotation speed increased. Furthermore, vibrations of the flow velocity profiles occurred at 500 rpm and 600 rpm at 10 and 20% W/O emulsion, whereas such vibration was not seen at 30% W/O emulsion.
