Systems and methods for casting propellant grain
Systems and methods for casting solid propellants include a mandrel for forming geometric features in a perforation of a propellant grain. In various embodiments, the mandrel includes a frangible portion that is removed from the propellant grain after the propellant grain has cured around the mandrel. A second portion of the mandrel may be left behind in the propellant grain. The mandrel may include a support structured disposed in the through hole of the mandrel. The support structure may include a plurality of longitudinal channels for directed exhaust gasses through the mandrel upon ignition of the propellant grain.
1. A mandrel for forming a solid propellant, comprising:
an elongated body extending in a longitudinal direction and comprising a first portion having a first wall thickness and a second portion axially adjacent the first portion;
wherein the second portion comprises a protuberant surface;
wherein an intersection of the first portion and the second portion has a wall thickness that is less than the first wall thickness, the intersection extending circumferentially around the elongated body; and
wherein the first portion is configured to break apart from the second portion at the intersection after a propellant grain has been cured around the elongated body.
2. The mandrel of claim 1 , further comprising a through hole disposed in the elongated body.
3. The mandrel of claim 2 , further comprising a support structure disposed in the through hole.
4. The mandrel of claim 3 , wherein the support structure comprises a plurality of longitudinal channels.
5. The mandrel of claim 1 , wherein the protuberant surface comprises a non-longitudinal feature.
6. The mandrel of claim 1 , further comprising a groove disposed in the elongated body, wherein the groove is disposed at the intersection between the first portion and the second portion.
7. The mandrel of claim 1 , further comprising an end portion and a tapered portion, wherein the end portion is coupled to the first portion via the tapered portion.
8. The mandrel of claim 1 , wherein the first portion and the second portion comprises a single, monolithic piece of material.
9. The mandrel of claim 8 , wherein the elongated body comprises a thermoplastic material.