Complex sentence: Both rotors turn in the same direction within the housing and are separated by a central section, inlaid in this central section are 12 vanes that can slide between one or the other rotor housing but do not turn with the engine's rotation.
Split into simpler sentences: Both rotors turn in the same direction within the housing and are separated by a central section. Inlaid in this central section are 12 vanes that can slide between one or the other rotor housing but do not turn with the engine's rotation.