نوع مقاله : مقاله پژوهشی
نویسندگان
1 پژوهشکده سامانه های حمل و نقل فضایی، پژوهشگاه فضایی ایران
2 دانشکده ی مهندسی هوافضا، دانشگاه صنعتی شریف
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
This research is conducted to study acceleration effect on the burning rate
augmentation of an aluminized solid propellant based on HTPB as an effective
factor determining combustion chamber pressure. A centrifugal experimental
setup was designed to obtain a uniform acceleration field by rotating the test
motor around its longitudinal axis. A cylindrical port propellant grain was
used in the test motor which had an inner diameter of 30 mm, an outer diameter
of 60 mm and a length of 52 mm, so acceleration vector was always perpendicular
to inner burning surface of propellant. Inner radius of tube was small, so the
magnitude of acceleration increased as the grain burned back. The pressure of
combustion chamber was changed from 30 bar 80 bar by changing the nozzle throat and the magnitude of acceleration changed from 2g to 60g by changing the
rotational speed of solid rocket motor. Pressure of combustion chamber was
measured. An analytical 0D code was used to compute burning rate augmentation
of propellant in acceleration field. Nozzle throat diameter is another
parameter controlling the pressure field of combustion chamber of solid rocket
motor. Thermomechanical erosion of nozzle throat is significant in aluminized
propellant, so erosion of graphite throat insert was measured and taken into
account in 0D code. Burning time of all tests was below 2 sec. due to small web
of the grain. As investigated, at low acceleration level (below 5g), burning
rate of propellant is not sensitive to acceleration while in the condition in which acceleration changed from 30g to 60g, burning rate augmentation ratio
increased from 1 to 1.5. The transient behavior of burning rate augmentation in
acceleration field was obvious in obtained results due to short burn time of
SRM. At high acceleration level, inner cylindrical surface of inhibitor was coated with aluminum oxide particles.
کلیدواژهها [English]
)
