ABSTRACT Cross-flow in packed bed reactors (PBRs) was often encountered in industries. However, the effect of inlet and outlet nozzle position on the droplet diameter was little considered. In this study, the effect of inlet and outlet nozzle angles of the gas on the spray disintegration was assessed by changing the angle (i.e., 0°, 30°, 45°, and 60°). A 3D computational fluid dynamic (CFD) model was involved to understand the influence of cross-flow of a single and two-phase gas–liquid flow in PBR. An Eulerian–Lagrangian approach (E-L) was used for solving the flow pattern and the spray disintegration. The RNG k-ε model was employed to simulate the turbulent flow. First, an indirect validation of the cross-flow packed bed was proposed based on a single phase. Second, the variation in parameters such as superficial liquid and gas velocity, mass flow rate, and gas angle orientation were investigated and graphically represented. A new correlation of Sauter mean diameter was developed using particle swarm optimization (PSO) with respect to gas angle orientation. This correlation was done for 64 cases and validated with existing correlations in the literature, giving an MAPE of ±12% and indicating a good agreement with the data.