On the Experimental and Numerical Droplet Generation in the Ordinary and Modified Micro channels with Oval Obstacle

The study of micro-scale fluid behavior is known as microfluidics, which has received much attention in many scientific fields. In the current research, the droplet generation in the micro channel has been studied numerically and experimentally. Two micro channels were fabricated by soft lithography method and the results of generated droplets were compared. The process of droplet formation was investigated using two fluids including water (dispersed fluid phase), and oil (continuous fluid phase) at different flow ratios. The images of the droplet formation and crossing steps in the micro channels were analyzed using image processing. The results showed that by increasing the ratio of dispersed to continuous flow, the size of droplets was increased, the droplet formation distance (the distance of the produced droplets) was increased, and the frequency of droplets generation was decreased. Also, the proposed new geometry leads to the production of smaller droplets with higher production frequencies. In the basic geometry, the droplet diameter was observed to be between 117 and 700 micrometers while in the proposed geometry, the diameter of droplets is between 46 and 466 micrometers. In the proposed geometry, the size of the produced droplets decreases, and the production frequency increases.