A two-dimensional, axisymmetric numerical model is used to study the effect of synthetic jet flow structure and thermal performance, validated with experimental data. The Reynolds number is set at 5473, and orifice-to-surface spacing (z/d) varies (2, 6, 10). Three square cross-section ribs at different radial positions are analyzed. Results show that ribs reduce heat transfer at the stagnation point, with a maximum decrease of 74.37% at z/d=10 for a 5mm×5mm rib at r/d=0.5 and a minimum of 47.70% at z/d=6 for the same rib. Heat transfer increases near the rib's leading edge but drops before and after the rib. No area-averaged heat transfer improvement is observed, with a maximum reduction of 69.24% at z/d=10 for a rib at r/d=2 and a minimum of 2.43% at z/d=6 for a rib at r/d=1. Stagnation pressure increases by 24.42% at z/d=2 and decreases by 15.66% at z/d=10 due to a rib at r/d=2.