Both the wind tunnel experiments and the numerical analyses on helium injections with various injector geometry configurations were performed in order to achieve high penetration and effective mixing between supersonic crossflow and injectant. The plume from the multiple-type injector, which is drawn upon the genetic algorithm, prevented plume diffusion because of aiming to reduce total pressure loss. The injectant from the orifice, which has sharp leading edge, mixed more effectively than the case of blunt leading edge injector and the smaller the half angle of the wedge shaped injector was, the larger the penetration height was obtained. In order to reduce the disturbance to the mainstream, the stinger shaped injector was proposed using the numerical analyses. When the stinger shaped injector was used, the penetration height increased by approximately 60% in comparison with the circular injector case and showed the most effective penetration performance. It is considerable that as the disturbance became smaller, the penetration height became larger. However, the stinger shaped injector has effective performance for the penetration in the condition of low dynamic pressure ratio only unlike the circular injector.