Afterburners have ensured supply of additional power/thrust for jet engines especially for combat operations/ difficult maneuvers. Presence of oxygen in flue gases escaping from the turbine could be gainfully used to extract additional power by supplying additional fuel for re-combustion of gases again in the afterburner. Only few experimental results are available for the afterburner for validating the computational results obtained using ANSYS^®Fluent. This paper investigates four afterburners with combustion chambers of lengths of 3 feet, 4 feet, 5 feet and 6.5 feet; with convergent-divergent nozzles. Other important components taken for consideration are fuel manifolds, vgutter, casing, and screech liner. 60° sector model of each afterburner is considered for analysis. Simple algorithm and realizable K-ε model with kerosene (C₁₂H₂₃) was utilized in carrying out steady state computational analysis with virtual injectors. Energy equation with discrete phase model was analysed. Multiple chemical reactions were solved with species transport selecting Finite Rate/ Eddy Dissipation model for combustion. CFD result of all four models with convergentdivergent nozzles were compared. It is evident that, 5 feet model of combustion model with convergent-divergent nozzle is recommended for production of maximum thrust which matches with experimental results available.