The effects of surface roughness and radiation on graphite nozzle erosion in solid rocket motors are studied. The physical domain considered extends from the upstream region of the nozzle throat through its exit. The incoming flow consists of the combustion products of nonmetallized AP/HTPB composite propellants. It is imperative to take into account the effect of surface roughness for long-duration firings because nozzle erosion continues to make the surface rough and even porous. The calculated nozzle erosion rates indicate that surface roughness exerts more significant influence than radiation, and more importantly, in opposite ways for nonmetallized propellants. Since both radiation and nozzle surface roughness are simultaneously present during the motor operation, and since they have opposite effects, the net nozzle-erosion rate may turn out to be close to the baseline value for smooth surface without radiative heat transfer.
All Science Journal Classification (ASJC) codes
- Aerospace Engineering
- Fuel Technology
- Mechanical Engineering
- Space and Planetary Science