In this work, a computational fluid dynamics (CFD)-assisted optimization study has been carried out, implementing geometric design modifications in a biomass cook stove (BCS) to achieve uniform air-fuel distribution. The work has been divided into two parts. The first part deals with the numerical investigations of fluid phase hydrodynamics and air-fuel homogeneous phase combustion. Simulations have been performed for a wide range of air velocities to predict the roles of primary and secondary airflow in improving the spatial airflow uniformity inside the BCS. The homogeneous combustion simulations show linear dependence of power and temperature on the air velocity and air-to-fuel ratio. The results indicate that the most optimized power output and temperature values are achieved when the grate is placed at a height of 25 mm, and the orifice plate with 15 holes of 10 mm each is located at a height of 105 mm from the bottom of the cook stove.