An axial compressor , comprising: a first stage having a first rotor and a first stator positioned such that a gap is defined between the first stator and the first rotor , the first stator having a first end , a hub and at least one vane extending along a longitudinal axis from the first end to the hub , the hub having a circumference defining one or more openings , and the first rotor including a seal coupled to the first rotor so as to be disposed a distance (D) away from the hub to define a hub cavity ; a second stage downstream from the first stage in a direction of a fluid flow, the second stage including a second rotor and a second stator ; a secondary flow system configured to direct fluid from the second stage into the first stator to improve at least one of a performance and a stability of the axial compressor ; wherein the secondary flow system is defined as a second plenum having a first end in communication with the first stator and a second end in communication with the second stator ; a first shroud housing positioned adjacent to the first stage, the first stator coupled to the first shroud housing and the first shroud housing defining a plenum over the first stator ; and the plenum defined over the first stator in communication with the secondary flow system , the plenum having at least one opening in communication with the first stator to direct the fluid from the secondary flow system into the first stator at the first end , wherein the at least one vane includes a passage in communication with the at least one opening of the plenum and in communication with the one or more openings of the hub to enable the fluid from the secondary flow system to flow through the passage and into the hub cavity , and from the hub cavity , the fluid from the secondary flow system flows through the gap . a first stage having a first rotor and a first stator positioned such that a gap is defined between the first stator and the first rotor , the first stator having a first end , a hub and at least one vane extending along a longitudinal axis from the first end to the hub , the hub having a circumference defining one or more openings , and the first rotor including a seal coupled to the first rotor so as to be disposed a distance (D) away from the hub to define a hub cavity ; a second stage downstream from the first stage in a direction of a fluid flow, the second stage including a second rotor and a second stator ; a secondary flow system configured to direct fluid from the second stage into the first stator to improve at least one of a performance and a stability of the axial compressor ; wherein the secondary flow system is defined as a second plenum having a first end in communication with the first stator and a second end in communication with the second stator ; a first shroud housing positioned adjacent to the first stage, the first stator coupled to the first shroud housing and the first shroud housing defining a plenum over the first stator ; and the plenum defined over the first stator in communication with the secondary flow system , the plenum having at least one opening in communication with the first stator to direct the fluid from the secondary flow system into the first stator at the first end , wherein the at least one vane includes a passage in communication with the at least one opening of the plenum and in communication with the one or more openings of the hub to enable the fluid from the secondary flow system to flow through the passage and into the hub cavity , and from the hub cavity , the fluid from the secondary flow system flows through the gap . <EOS>