In this work, we consider an appropriate form of the viscous dissipation term in the integral form of the conservation equation, and examine the effects of momentum terms on the computed drop size in pressure-atomized sprays. The Sauter mean diameter (SMD) calculated in this manner agrees well with experimental data that included measurements of both the drop velocities and sizes. The revised treatment of liquid momentum also leads to quite stable calculations for a wide range of density ratios and injection velocities. Using this setup, injection parameters such as the spray cone angle and the atomization length can be directly input to the system of equations. Thus, this approach is capable of incorporating the effects of injection parameters, and can be used for further considerations of the drop and velocity distributions under a wide range of spray geometry and injection conditions.