Renewable hydrogen energy development has grown in significance as countries seek to reduce their carbon footprints in recent years. Nel Hydrogen uses a process called electrolysis to produce hydrogen which uses an electrolyzer. The electrolyzer splits water molecules into hydrogen and oxygen. However, not all of the water is split in one pass, and water and oxygen leaves the electrolyzer in one stream along with a separate stream of pure hydrogen. To recycle the water stream and feed it through the electrolyzer again, Nel uses a water-oxygen separator following the electrolyzer to separate the pure water from the oxygen bubbles. The goal of our project was to develop a method to assist in the design and optimization of the phase separator. We accomplished this by using the software ANSYS Fluent to simulate this separator. Our group designed a new tank with baffles and varied velocity, tank length, and baffle length. Next, we used the data extracted from ANSYS and ALAMO, a symbolic regression software, to produce a mathematical model describing the separation efficiency taking specific variables and physical principles into account. By optimizing the separation efficiency of a water-oxygen separator, the overall electrolysis efficiency and infrastructure longevity will improve.