## THERMAL SCIENCE

International Scientific Journal

### Thermal Science - Online First

online first only
### Kinetic characterization of low-velocity positive collision of double droplets

**ABSTRACT**

Droplet positive collision is a complex process involving heat transfer in gas-liquid-solid three-phase flow and droplet collide dynamics. In order to study the kinetic behavior of droplets under positive collision in low velocity (v<2 m/s), this paper focuses on the spreading, vibration and fracture characteristics of double droplets by numerical simulation. First, the accuracy of the model is verified by experimental comparison. The effects of droplet diameters, collision velocities and wall contact angles on the spreading process are analyzed, and the spreading factor curves are plotted. Then, the droplet rebound vibration after collision fusion is equated to a single-degree-of-freedom damped vibration system, and the peak vibration height variation curve of the fused droplet is obtained by nonlinear fitting. Considering the droplet phase change, the influence law of different conditions on the vibration damping factor and vibration time of the fused droplet is studied. Finally, it is found that rebound fracture and spreading fracture occur after the fusion of double droplets under positive collision, and the critical values of collide velocity required for the occurrence of the above phenomenon are found. To provide a reliable theoretical basis for the study of heat and mass transfer processes after multiple droplets collide the wall.

**KEYWORDS**

PAPER SUBMITTED: 2023-06-13

PAPER REVISED: 2023-09-23

PAPER ACCEPTED: 2023-10-07

PUBLISHED ONLINE: 2023-11-11

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