A computing system includes memory configured to store instructions and a nozzle library, and a processor configured to access the memory and to execute the instructions. The instructions cause the computing system to select at least one nozzle unit as a selected at least one nozzle unit based on the nozzle library and to place the selected at least one nozzle unit at corresponding location coordinates, to create multiple volume meshes for the process chamber, and to simulate the flow of the gas through the selected at least one nozzle unit in the process chamber based on the multiple volume meshes in the process chamber. The nozzle library includes information about multiple nozzle units of which each has multiple volume meshes formed therein. The nozzle units have different shapes from each other.