<p>Supersonic Biplane and its modification to the geometry are being investigated by many researchers to find the possible solution and possibilities for a futuristic supersonic transport that could have the low wave drag and minimal effect of sonic boom. The Busemann Biplane is the one that strongly agrees with those possibilities, using shock cancellation and shock interaction phenomena between the Biplane elements but only at a design Mach number. At Off-design Mach numbers, Busemann biplane faces the flow chocking and generates large wave drag due to its convergent divergent section. In this paper, the effect of injection velocity on the performance of the Busemann Biplane is investigated at non-lifting condition at the free stream Mach number of 1.6 using numerical simulations (CFD). The results suggest that the injection velocity between biplane elements reduces the pressures between the biplane elements and reduces the drag penalties at off-design Mach number of 1.6</p>