15-12-2012, 05:07 PM
Thrust Vector Control
Thrust Vector.pdf (Size: 3.14 MB / Downloads: 90)
Abstract
The objective of this project was to design, build and test a thrust‐vectoring
system for a solid booster rocket. The project was sponsored by Stellar
Exploration. A two member team of Harsimran Singh and Dane Larkin worked
toward the objective.
Introduction
The project described in this document is a thrust vectoring system that will be implemented in
Stellar Exploration’s solid fuel test rocket. This document will outline Background research on
the status of thrust vector control, the project requirements and objectives, how the success of
the project will be evaluated, and prototype design. In addition the methods used and the
timeline the project will follow will be thoroughly outlined. The success of this project is
dependent on the cooperation of Dane Larkin and Harsimran Singh and on the participation of
their sponsor Stellar Exploration at each part of the process. Dane Larkin and Harsimran Singh
are responsible for delivering a viable prototype to Stellar Exploration. Stellar exploration is
expected to review the progress and design reviews at each stage of the design. The final goals
of this project are to design and build a functioning thrust vectoring system for use by Stellar
Explorations.
Background
Stellar Exploration Incorporated is a small technology company which focuses on lowcost
scientific and space exploration projects. The company hires approximately three full time
engineers. Stellar Exploration requires a thrust vectoring system for its Silver Sword rocket. By
allowing operators to control the direction of thrust, the thrust vectoring system will make up
for the drag produced and loss in performance incurred by the rocket fins. What follows is a list
of background research on different thrust vectoring systems which have been used in the past.
Fixed nozzle systems
Fixed nozzle systems as the name states refer to nozzles that are solid mounted in the
frame of the vehicle. The flow inside the nozzle itself is then changed to move the thrust vector.
These were some of the first systems of thrust vector control developed in the Polaris and
minute man rockets. The classification of fixed nozzle systems falls into these categories,
secondary injection systems where the flow is the nozzle is changed by the addition or
rerouting of fluid flow, and mechanical deflection where a mechanical element changes the
direction of flow.
Liquid injection
Liquid injection encompasses any addition of a fluid that changes the characteristics of
the combustion. By changing the combustion on one side of the nozzle the thrust vector can be
changed. The method of injection, as well as the fluid that is injected, are both topics of much
debate and research. one of the biggest decisions when considering this method of thrust
vectoring is the liquid that will be used the two main divisions are whether the liquid will inhibit
the combustion or contribute to combustion. Combustion inhibitors will tend to cool one side
of the nozzle while combustion contributors will add fuel or other additives to increase thrust
on one side of the nozzle. Advantages of this method of thrust vectoring are that it has fast
response capability and add to thrust by adding mass to the fluid stream. The disadvantages of
this system are that they are heavy and the amount the valve opens is not linearly related to
the rate of change of the thrust vector.
Gas injection
Gas injection is very similar to liquid injection the difference being that instead of new
gas being added to the fluid stream combustion gasses are rerouted from behind the nozzle
into the diverging section changing the flow through the nozzle itself. The advantages of this
method are that additional fluids do not need to be stored onboard and so the system overall is
lighter in weight.