Erosion in Solid-Propellant Rocket Motor Nozzles with Unsteady Nonuniform Inlet Conditions

摘要

A computational framework is developed to investigate nozzle erosion in solid-propellant rocket motors. Thencalculations have several novel features. Among these is an accounting of three-dimensional effects, most strikinglynfor a vectored nozzle but also in the description of the turbulent flow.Also, instead of the hitherto universal strategy ofnmerely solving the nozzle flow with uniform inlet conditions, strategies by which the chamber flow with itsnnonuniformefflux can be coupled to the nozzle flowwhile still resolving the nozzle boundary layer are discussed. Thenchamber flow is approximated by either full motor simulations, which do not resolve the boundary layer, or by annasymptotic strategy valid for slender chambers: one first used in turbulent boundary-layer studies. The manner innwhich the chamber efflux conditions are used as nozzle inlet conditions is part of the discussion. The results suggestnthat specifying turbulent rather than uniform inlet conditions can have a significant effect on nozzle erosion.