Ladder Charge Solid Rocket Motor Ignition Transient Flow Field Characteristics

Solid rocket motor ignition process is a unsteady process of short and complex, this paper charge for ladder-shaped solid rocket motors which was maturely applied on the M21 rocket weapon, and its ignition process was analyzed. A double-way jet ignitor is used in ladder-shaped solid rocket motor, its ignition transient have the ignition characteristics of both head-ignition and tail-ignition, the ignition gas and combustion chamber burning gas was converged, and form a complex flow field.According to the characteristics of ladder-shaped solid rocket motor to establish the unsteady two-dimensional axisymmetric model, and using FLUENT software, through the UDF program on the ignition within the flow field numerical simulation, and study the ignition transient flow field characteristics of ladder-shaped solid rocket motor, obtained pressure and temperature distribution and dissemination of ignition process in front-chamber and back-chamber, early in the ignition with the ignitor in the vicinity back and front of the ignitor-nozzle, there is a very strong shock wave and vortex phenomena, and for different time characteristics of different parts of the relevant parameters were analyzed and compared, in addition to the propellant gas by considering whether the increase in the quality of the conditions, get the importance of increase the quality of the propellant gas during the process of pressure-buildup.Accroding to the ignitor in the special way with the structure and placement of ladder-shaped solid rocket motor, ignitor mass flow rate characteristics and the radius of igniter-nozzle act on the impact of flow field were considered. By setting a different role in the ignition with the ignition time to be a corresponding mass flow rate characteristics, and were analyzed 100ms,125ms,150ms,175ms,200ms ignition with the five different roles within the time period corresponding to the flow field, obtained with different mass flow rate of the ignition characteristics of the ignition at different time during different patterns of flow field, and for the moment appears to open nozzle covers the "relief of secondary peak" phenomenon is analyzed. For the radius of 2mm,4mm,6mm,8mm,10mm,12.5mm, different igniter-nozzle radius act on the flow field of internal, and make numerical simulation and analysis, for the early ignition because of igniter-nozzle changes in the radius of the "jet effect" was studied, front and back of the combustion chamber for different parts of the local flow field characteristics and the overall flow field were compared analysis, obtained with a nozzle in changing the radius of the ignition conditions, the temperature is more sensitive than the changes in pressure.By analysis the internal flow field characteristics of ladder-shaped solid rocket motor during ignition transient, obtained the flow field in different time, different part and different conditions, for the study of ignition transient process and related characteristics of ladder-shaped solid rocket motor provide theory and references.