Patent ID: 6711901
Filing Date: 2004-03-30
Classification: C23C,F02K,F05D,H04L,Y10T

Abstract:
A nozzle assembly having a converging/diverging pathway with a throat and an exit region, the nozzle assembly being operatively engageable to a rocket motor case to receive high temperature combustion products generated in the rocket motor case upon ignition of propellant loaded in the rocket motor case and to pass the combustion products through the throat before the combustion products are discharged from the exit region, the nozzle assembly comprising:(i) an annular throat insert comprising an annular throat support and an annular shell positioned radially inside the throat support, the throat support comprising at least one carbon-based material and having a forward face or edge, a radially inner converging portion that converges into a minimum cross-sectional area portion at the throat, and a radially inner diverging portion aft of the minimum cross-sectional area portion; (ii) said the shell comprising at least one refractory metal or refractory metal alloy having: (a) a forward surface region covering at least a portion of the converging portion of the throat support; (b) a throat surface region covering the minimum cross-sectional area portion of the throat support, the throat surface region defining the throat and exposed along the converging/diverging pathway; and (c) an aft surface region covering at least a portion of the diverging portion of the throat support; (iii) a protective eyelid comprising at least one member selected from the group consisting of a carbon-based material and a silica-based material, the protective eyelid covering the forward face or edge of the throat support to prevent the combustion products passing along the converging/diverging pathway from reaching a radially outer surface of the throat insert, yet the protective eyelid not covering the throat surface region of the shell so that the throat surface region of the shell remains exposed to the combustion products passing along the converging/diverging pathway during operation of the rocket motor assembly; and (iv) an aft skirt configured as a diverging truncated cone, the aft skirt extending aftwardly from the throat insert.