The Practical Design of Fluid Injection Thrust Vector Control Systems

The rocket system designer has many alternate choices which must be made during selection of a thrust vector control subsystem. Some suggestions for making these choices are:

1. 1.
   The best point of fluid injection usually occurs about one-third of the distance from the throat of the nozzle to the end of the expansion cone.
2. 2.
   Liquid or gas injection will usually have less weight penalty to the rocket only when the total burning of the rocket stage is less than 60 sec.
3. 3.
   To get best reliability factor for the system, it should have capability of operating in presence of contamination.
4. 4.
   Basic injector valve design and performance is controlled by four parameters; maximum mass flow rate, slew response, frequency response, and hysteresis.

A block diagram of a TVC system is presented which is a good model for examining the low frequency dynamic characteristics of the system.