This paper performs a numerical study to enhance transonic supercritical Coflow Jet (CFJ) airfoil cruise performance by placing the CFJ downstream of the normal shock wave. The Reynolds averaged Navier-Stokes(RANS) equations with one-equation Spalart-Allmaras turbulence model is used. A 3rd order weighted essentially non-oscillatory (WENO) scheme with a low diffusion Riemann solver is utilized to evaluate the inviscid fluxes. A 2nd order central differencing scheme is employed for the viscous terms. Numerical trade studies are carried out to investigate CFJ location effects on the shock location and the airfoil efficiency enhancement. This research discovers that placing a CFJ downstream of a shock wave, results in an induction effect that moves the shock further downstream with enlarged supersonic region. Furthermore, the CFJ placed downstream of the shock wave will not suffer the entropy increase due to the shock boundary interaction occurring between the CFJ injection and suction. It substantially reduces the CFJ power expenditure. The effects enhance the cruise efficiency of the supercritical airfoil for both the coefficient of lift CL and the aerodynamic efficiency (L/D)c, which takes into consideration the power required to run the CFJ. The study shows that the aerodynamic efficiency is increased by 5.26% over the baseline RAE2822 and decreasd by 6.68% over the standard CFJ-RAE2822. Measuring by peak (C2 L/CD)c results in an efficiency increase of 6.68% over the baseline RAE2822 and a decrease of 17.51% over standard CFJ-RAE2822.