|Abstract or Summary
- A high speed motion neutron radiography system has been developed
at Oregon State University which is capable of taking high speed
neutron radiographs of events which occur on the order of one to two
milliseconds or more. This system was used previously to demonstrate
the application of high speed motion neutron radiography techniques to
two phase flow and to the burning of solid propellants. Results of
this effort showed the burning patterns and relative distributions of
the propellant and gases during the burning of these propellants. This
system has been modified and the techniques adapted and further
developed for the investigation of similar phenomena which occur with
the burning of liquid propellants. The purpose of this thesis is to
demonstrate the feasibility of using the new system and techniques for
the investigation of liquid streams which were used to simulate the
injection of liquid propellants into a pressurized steel chamber.
Examples of the application of these new techniques to liquid streams
injected into an unpressurized steel chamber are presented.
The high speed system is capable of taking neutron radiography
movies at frame rates up to about 11,000 frames per second, although
about 5000 frames per second proved to be adequate for liquid streams.
In order to use the high speed system for liquid streams several
modifications and improvements were investigated, especially with
regards to the synchronization method. A new fission probe method was
developed which provided 100% reliability in the synchronization of
events (over four orders of magnitude in time are covered) as compared
with the 50% rate experienced with the previous time delay method.
Other modifications include an improved method of masking of the
object/event, an improved imaging system including a new image
intensifier, new scintillator screens, and a new fiber optics coupling,
and several methods of neutron flux enhancement. With the new system
and techniques the position, distribution, and relative motion and
sizes of liquid streams injected into a steel pipe or chamber could be
measured. When applied to burning liquid propellants the distribution
of the liquid and gas phases of the propellant could be determined.
Applications of the current Oregon State University High Speed
Motion Neutron Radiography Facility include the investigation of the
flow dispersion patterns of liquid streams due to flow blockages or
disruption objects; the investigation of diesel fuel injection
mechanisms; and the investigation of a wide range of two phase flow
situations, with particular emphasis on nuclear reactor related
phenomena such as boiling boundaries, quench front motion, and boiling