Two-pulse gas generator and operation method thereof

A gas generator comprising:

• a pressure vessel;
• an outer propellant in the pressure vessel, the outer propellant having a tubular shape;
• an inner propellant inside the outer propellant, the inner propellant having a columnar shape;
• a barrier membrane configured to isolate the outer propellant and the inner propellant from each other;
• a first igniter configured to ignite the inner propellant;
• and
• a second igniter configured to ignite the outer propellant,
• wherein the inner propellant has a forward end surface facing a combustion space in the pressure vessel and a side surface,
• wherein the side surface of the inner propellant is isolated from the combustion space,
• wherein the barrier membrane comprises a first barrier membrane covering a forward end surface of the outer propellant, and a second barrier membrane connected to the first barrier membrane via a vulnerable portion and covering an inner surface of the outer propellant,
• wherein the vulnerable portion faces the combustion space, faces the forward end surface of the outer propellant, and is positioned adjacent to a forward end of the outer propellant,
• wherein the first igniter is positioned at a forward end of the pressure vessel,
• wherein the second igniter is positioned at a rearward end of the pressure vessel and adjacent to a rearward end of the outer propellant for leading ignition gas to the inner surface of the outer propellant,
• wherein the second barrier membrane covers the forward end surface of the outer propellant in addition to the inner surface of the outer propellant, and
• wherein an end portion of the first barrier membrane and an end portion of the second barrier membrane are bonded to each other over an entire periphery.