This study focuses on enhancing the performance of turbomachines through the design of multi rotor configurations. Specifically, the effect of the distance between an axial inducer and a centrifugal impeller, which rotates independently in both co-rotation and counter-rotation modes, is investigated in a turbopump. The study parameters include the speed ratio and the distance between the inducer and impeller. Numerical results for the centrifugal impeller are validated through experimental testing, and two inducers with the same geometrical characteristics but with inverse tip angles are designed. Results show that changing the distance between the inducer and impeller, as well as the speed ratio, can have a significant impact on the turbomachine's performance.