Modeling of the chamber flowfield in a rod-and-tube configuration solid rocket motor

Currently, DRDC Valcartier is designing a prototype rod-and-tube configuration solid propellant rocket motor that will propel a hypersonic velocity missile. This configuration will incorporate a very low port-to-throat area ratio, which in turn results in very high velocity propellant gas traveling across burning propellant surfaces, particularly near the nozzle end of the rocket. Typically the phenomenon known as erosive burning is present in low port-to-throat ratio motors. While numerical and lumped parameter models are available to design and analyze solid propellant rocket motors and nozzles, many of them provide solutions based on the assumption of quasi-steady flow. Due to the high pressure, high velocity and highly transient nature of the flows expected in the motor under design, it is believed that a CFD simulation will better model the time-dependent phenomena that occur during the functioning of a motor of this type. This simulation couples the fluid dynamics and heat transfer of the gas flowfield within the rocket port to the nozzle and the regression rate of the propellant which is governed by the Lenoir-Robillard erosive burning law. By incorporating regression into the model, the information provided by the resulting time-accurate solution will enable a much improved understanding of the flow phenomena within this rod-and-tube grain motor, which in turn will help in the design of both the motor and the nozzle. The methodology developed within this thesis is widely applicable and supports the use of different erosive burning models, as well as non-steady-state three-dimensional CFD modeling.