The ignition and combustion characteristics of a single droplet or double droplets of the Al/n-heptane-based nanofluid fuels with different arrangements were investigated by a droplet-suspension method at high temperature. The addition of ricinoleic acid and nano-sized Al particles to n-heptane can improve the ignition performance of n-heptane droplets, and the ignition delay times of n-heptane droplets are decreased by the maximum of 19.0% and 31.0%, respectively. The mixing effect of combustible vapor of adjacent droplets and the heat transfer effect of adjacent flames are responsible for the different combustion processes of nanofluid fuel droplets with different arrangements. Compared with the single droplet, the ignition delay times of the horizontal and vertical double droplets are decreased by the maximum of 26.9% and 45.7%, respectively. The vertical double droplets have better ignition performance than the horizontal double droplets due to the disturbance and mixing of the vapor flow with different directions. In addition, the droplet arrangement has different promotion effects on different droplets.
We have studied the levitation and oscillation dynamics of complex drops containing two immiscible liquids. Two types of drops, core-shell drop and abnormal-shaped drop, have been obtained depending on the levitation procedures. The oscillation dynamics of the drops have been studied using a high speed camera. It has been found that the oscillation of the abnormal-shaped drop has a longer oscillation period and decays much faster than that of the core-shell drop, which cannot be accounted for by the air resistance itself. The acoustic streaming induced by ultrasound may bring an additional force against the motion of the drop due to the Bernoulli effect. This is responsible for the enhanced damping during the oscillation in acoustic levitation.
危险品化学品经营许可证（带存储）