Abstarct: Abstract Droplet coalescence on flat surfaces plays an important role in controlling fluid behavior and improving the efficiency of industrial processes. In this thesis, the effect of geometric parameters including surface angle and droplet generation module distance, along with mechanical vibrations, on droplet coalescence characteristics was investigated. For this purpose, a laboratory setup was designed and built that allowed for controlled droplet generation, high-speed image capture, and processing to extract droplet number, average size, dispersion, and sphericity indices. The results showed that increasing the module distance increased the number of droplets and decreased their average size, while decreasing the surface angle resulted in the formation of smaller, more uniform, and higher sphericity droplets. Also, applying controlled mechanical vibrations accelerated the coalescence process and resulted in a decrease in droplet number, increase in size, geometric deformation, and significant change in dispersion. These findings provide a comprehensive picture of the dynamics of droplet coalescence and demonstrate that simultaneous control of geometric parameters and mechanical vibrations can be an effective tool for optimizing droplet behavior. Such an approach is applicable to many industrial systems, including solar desalination technologies.