This study focuses on the investigation of fluid flow in a Convergent-Divergent (C-D) nozzle with four inlets. The nozzle geometry comprised a convergent angle of 45 °and a divergent angle of 15 °. Computational Fluid Dynamics (CFD) simulations were conducted to analyze the behavior of the flow within the C-D nozzle under varying inlet Mach parameters ranging from 2 to 5. The stream characteristics inside the nozzle were analyzed using Computational Fluid Dynamics (CFD) simulations. This study examined crucial parameters such as maximum pressure, minimum pressure, maximum velocity, and outlet Mach number, which are essential for understanding the behavior and performance of the flow. Fluent software, which is a well-established computational fluid dynamics tool, was used to conduct simulations and analyze the flow characteristics. The results obtained shed light on the behavior of the fluid flow and provide valuable insights into the performance of the C-D nozzle at different inlet Mach parameters. This research contributes to a deeper understanding of the C-D nozzle performance and its applications in various engineering fields, such as aerospace and propulsion systems. These findings may have significant implications for optimizing nozzle design and enhancing overall system efficiency.