A reusable oxidizer-cooled annular aerospike nozzle was designed for testing on a labscale PMMA-N20[1] hybrid rocket motor at Cal Poly-SLO.[2] 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.
[1] PMMA stands for polymethyl methacrylate, a thermoplastic commonly known by the brand name Plexiglas®. N2O is the molecular formula for nitrous oxide.
[2] California Polytechnic State University, San Luis Obispo
","abstract_html":"<p>A reusable oxidizer-cooled annular aerospike nozzle was designed for testing on a labscale PMMA-N<sub>2</sub>0<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 N<sub>2</sub>O 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<sup>®</sup>. N<sub>2</sub>O 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>","abstract_has_math":false,"creators":["Grieb, Daniel Joseph"],"institution":null,"degree_name":"MS in Mechanical Engineering","degree_level":null,"degree_discipline":"Mechanical Engineering","degree_department":null,"school":null,"contributors":["Joseph D. Mello"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2012,"date_issued":"2012-02-01T08:00:00Z","date_published":"2012-02-01T08:00:00Z","updated_at":"2026-07-24T01:31:11Z","subjects":["Aerospike Nozzle","Finite Element Analysis","Hybrid Rocket","Two-Phase Flow","Nitrous Oxide","Propulsion and Power"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["10.15368/theses.2012.7"],"render_values":[{"text":"10.15368/theses.2012.7","href":"https://doi.org/10.15368/theses.2012.7","code":true}]}]},"links":{"outbound_url":"https://digitalcommons.calpoly.edu/theses/692","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Joseph D. Mello"]},{"key":"dc:creator","label":"Author","values":["Grieb, Daniel Joseph"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.available","label":"Dc Date Available","values":["2012-03-11T08:00:00Z"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Mechanical Engineering"]},{"key":"thesis:degree_name","label":"Degree Name","values":["MS in Mechanical Engineering"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Aerospike Nozzle","Finite Element Analysis","Hybrid Rocket","Two-Phase Flow","Nitrous Oxide","Propulsion and Power"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://digitalcommons.calpoly.edu/theses/692","10.15368/theses.2012.7"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["A reusable oxidizer-cooled annular aerospike nozzle was designed for testing on a labscale PMMA-N20[1] hybrid rocket motor at Cal Poly-SLO.[2] 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.
[1] PMMA stands for polymethyl methacrylate, a thermoplastic commonly known by the brand name Plexiglas®. N2O is the molecular formula for nitrous oxide.
[2] California Polytechnic State University, San Luis Obispo
"]},{"key":"dc:title","label":"Title","values":["Design and Analysis of a Reusable N2O-Cooled Aerospike Nozzle for Labscale Hybrid Rocket Motor Testing"]}]}],"canonical_facts":{"dc:contributor":["Joseph D. Mello"],"dc:creator":["Grieb, Daniel Joseph"],"dc:date.available":["2012-03-11T08:00:00Z"],"dc:description.abstract":["A reusable oxidizer-cooled annular aerospike nozzle was designed for testing on a labscale PMMA-N20[1] hybrid rocket motor at Cal Poly-SLO.[2] 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.
[1] PMMA stands for polymethyl methacrylate, a thermoplastic commonly known by the brand name Plexiglas®. N2O is the molecular formula for nitrous oxide.
[2] California Polytechnic State University, San Luis Obispo
"],"dc:identifier":["https://digitalcommons.calpoly.edu/theses/692","10.15368/theses.2012.7"],"dc:subject":["Aerospike Nozzle","Finite Element Analysis","Hybrid Rocket","Two-Phase Flow","Nitrous Oxide","Propulsion and Power"],"dc:title":["Design and Analysis of a Reusable N2O-Cooled Aerospike Nozzle for Labscale Hybrid Rocket Motor Testing"],"thesis:degree_discipline":["Mechanical Engineering"],"thesis:degree_name":["MS in Mechanical Engineering"]},"updated_at":"2026-07-24T01:31:11Z"}