Mk IIb Hybrid Rocket Combustion Chamber Design
The purpose of this project is to test the thrust vector control of liquid injected Nitrous Oxide on a small scale, grounded rocket. Our Mk V rocket will be a single stage 3000 lbf thrust rocket capable of reaching the ionosphere with a thrust vectoring control system. Before we build this system on a large scale, we want to have a proof of concept through testing of the Mk IIb which stands at 8 feet tall whereas the Mk V stands at approximately 30 feet!
My team, of which I am lead was tasked with designing the combustion chamber. In a hybrid designed rocket, there is both solid and liquid fuel. The solid fuel is the black cylinder which is composed of HTPB (a type of artificial rubber found in various industries). The valve on the top plate feeds the NOS (liquid fuel) through the manifold and injectors (of which there are 8 in total). The prechamber design incorporates a 0.25" thick tube of cotton phenolic, an excellent insultator, to prevent prechamber temperatures from burning through the motor casing. Because this design will not fly and will be bolted to a static test stand, we were able to design all parts with a safety factor of 3. We also have the option to make many of the parts out of steel instead of the go to Aluminum 6061 because weight is not an issue; the advantage of this is that steel has more resilient thermal properties and can withstand more force, pressure, and temperatures.
The NOS that will be liquid injected add vectored thrust to the nozzle and are inserted after the throat (similar to Afterburners on jet aircraft). Please feel free to email me for further detail of this design.
Check out our team website!
My team, of which I am lead was tasked with designing the combustion chamber. In a hybrid designed rocket, there is both solid and liquid fuel. The solid fuel is the black cylinder which is composed of HTPB (a type of artificial rubber found in various industries). The valve on the top plate feeds the NOS (liquid fuel) through the manifold and injectors (of which there are 8 in total). The prechamber design incorporates a 0.25" thick tube of cotton phenolic, an excellent insultator, to prevent prechamber temperatures from burning through the motor casing. Because this design will not fly and will be bolted to a static test stand, we were able to design all parts with a safety factor of 3. We also have the option to make many of the parts out of steel instead of the go to Aluminum 6061 because weight is not an issue; the advantage of this is that steel has more resilient thermal properties and can withstand more force, pressure, and temperatures.
The NOS that will be liquid injected add vectored thrust to the nozzle and are inserted after the throat (similar to Afterburners on jet aircraft). Please feel free to email me for further detail of this design.
Check out our team website!
Here is a cross-sectioned view of the injector bulkhead
Here is a full view and a rendered cross-sectioned view of the combustion chamber.