Design and Analysis of a Reusable N2O-Cooled Aerospike Nozzle for Labscale Hybrid Rocket Motor Testing

<p>A reusable oxidizer-cooled annular aerospike nozzle was designed for testing on a labscale PMMA-N₂0<a href="http://digitalcommons.calpoly.edu/cgi/ir_submit.cgi#_ftn1">[1]</a> hybrid rocket motor at Cal Poly-SLO.<a href="http://digitalcommons.calpoly.edu/cgi/ir_submit.cgi#_ftn2">[2]</a> The detailed design was based on the results of previous research involving cold-flow testing of annular aerospike nozzles and hot-flow testing of oxidizer-cooled converging-diverging nozzles. In the design, nitrous oxide is routed to the aerospike through a tube that runs up the middle of the combustion chamber. The solid fuel is arranged in an annular configuration, with a solid cylinder of fuel in the center of the combustion chamber and a hollow cylinder of fuel lining the circumference of the combustion chamber. The center fuel grain insulates the coolant from the heat of the combustion chamber. The two-phase mixture of nitrous oxide then is routed through channels that cool the copper surface of the aerospike. The outer copper shell is brazed to a stainless steel core that provides structural rigidity. The gaseous N₂O flows from the end of aerospike to provide base bleed, compensating for the necessary truncation of the spike. Sequential and fully-coupled thermal-mechanical finite element models developed in Abaqus CAE were used to analyze the design of the cooled aerospike. The stress and temperature distributions in the aerospike were predicted for a 10-sec burn time of the hybrid rocket motor.</p> <br /> <p><a href="http://digitalcommons.calpoly.edu/cgi/ir_submit.cgi#_ftnref1">[1]</a> PMMA stands for polymethyl methacrylate, a thermoplastic commonly known by the brand name Plexiglas^®. N₂O is the molecular formula for nitrous oxide.</p> <p><a href="http://digitalcommons.calpoly.edu/cgi/ir_submit.cgi#_ftnref2">[2]</a> California Polytechnic State University, San Luis Obispo</p>

Name thesis:degree_name

MS in Mechanical Engineering

Discipline thesis:degree_discipline

Mechanical Engineering

Year dc:date.available

2012

Author dc:creator

• Grieb, Daniel Joseph

Contributors dc:contributor

• Joseph D. Mello

• Aerospike Nozzle
• Finite Element Analysis
• Hybrid Rocket
• Two-Phase Flow
• Nitrous Oxide
• Propulsion and Power

Identifier

10.15368/theses.2012.7

OAI identifier oai:identifier

oai:digitalcommons.calpoly.edu:theses-1735