The TAB method is a numerical approach for calculating droplet breakup in engine sprays. It is based on an analogy between an oscillating and distorting droplet and a spring-mass system, where the restoring force is analogous to surface tension and the external force is analogous to gas aerodynamic forces. The method accounts for damping due to liquid viscosity and predicts the state of oscillation and distortion of droplets. It is more accurate than the Reitz method in predicting droplet breakup and provides more consistent results with experimental data. The TAB method also predicts the normal velocity of product drops, which determines the initial spray angle without requiring it to be input. The method uses a dimensionless constant derived from theoretical and experimental results to determine breakup times and drop sizes. The TAB method has been validated against experimental data and shows good agreement with measurements. The method is implemented in the KIVA computer program and has been used to simulate diesel sprays. The results show that the TAB method gives different drop sizes near the injector compared to the Reitz method, but similar results downstream when back-pressure is low. At higher back-pressures, the TAB method gives larger drop sizes than the Reitz method and experiments. The method has several advantages over the Reitz method, including the ability to predict the state of oscillation and distortion of droplets and the inclusion of liquid viscosity effects. The TAB method is a promising alternative for calculating droplet breakup in engine sprays.The TAB method is a numerical approach for calculating droplet breakup in engine sprays. It is based on an analogy between an oscillating and distorting droplet and a spring-mass system, where the restoring force is analogous to surface tension and the external force is analogous to gas aerodynamic forces. The method accounts for damping due to liquid viscosity and predicts the state of oscillation and distortion of droplets. It is more accurate than the Reitz method in predicting droplet breakup and provides more consistent results with experimental data. The TAB method also predicts the normal velocity of product drops, which determines the initial spray angle without requiring it to be input. The method uses a dimensionless constant derived from theoretical and experimental results to determine breakup times and drop sizes. The TAB method has been validated against experimental data and shows good agreement with measurements. The method is implemented in the KIVA computer program and has been used to simulate diesel sprays. The results show that the TAB method gives different drop sizes near the injector compared to the Reitz method, but similar results downstream when back-pressure is low. At higher back-pressures, the TAB method gives larger drop sizes than the Reitz method and experiments. The method has several advantages over the Reitz method, including the ability to predict the state of oscillation and distortion of droplets and the inclusion of liquid viscosity effects. The TAB method is a promising alternative for calculating droplet breakup in engine sprays.