In this paper, a numerical analysis is presented on the Francis turbine, based on computational fluid dynamics (CFD). The aim of this study is to evaluate the hydraulic efficiency and performance of the Francis turbine by varying the mass flow rate and the runner blade numbers using commercially available CFX code. The inherent turbulence of water flow through turbine passages is accurately captured by the SST turbulent model. The numerical simulation has been conducted under different loading part loads, rated load, and overload conditions with varying the number of runner blades (13, 15, and 17). Based on CFD analysis, the numerical results indicate that the hydraulic efficiency is maximum at the rated load condition. The results obtained from the numerical analysis were validated by comparing them with turbine manufacturer data available in the literature. The efficiency of the turbine has been found to be maxima with 15 runner blades, compared to 13 and 17 runner blades. Additionally, the fluctuation in pressure distribution was lower with 15 run ner blades. In terms of velocity streamline, the most stable fluid flow condition is observed with 15 runner blades at the rated load condition, in comparison to the other blade configurations. The findings of this numerical simulation study can be valuable for researchers interested in investigating the effects of different parameters on the performance characteristics of the Francis turbine.