Sunday, 8 July 2007
At this meeting, Design Option #6 was viewed as promising, avoiding large size (38mm) inside or outside threading or the use of circlips. At the same meeting, it was decided that the two core challenges from now on were the Nozzle Design and Injector Design. The focus of work in Chimera will now be upon these two design challenges, as well as experiements in machining plastic rod for reloads. (The idea of using home made reloads with a commercial rocket motor was mooted)
Saturday, 23 June 2007
Other materials we have ordered include PVC, PE (polypropylene), HDPE (high density polyethylene) and UHMWPE (ultra high molecular weight polyethylene).
PVC and PE are used in SkyRipperSystems commercial Hybrid motors. HDPE has been used in hybrid design. UHMWPE might offers advantages of more material being ejected, and therefore higher thrust. Presumably, this is all to do with the density of the plastic. Some of these plastics may be very difficult to machine or drill. This is why Chimera will be doing some experiments.
Saturday, 16 June 2007
Tuesday, 12 June 2007
Monday, 11 June 2007
Everything about a hybrid motor can be made, but we cannot make anything unless we have materials. The main two materials needed are aluminum for the case and plastic for the reload. It is proving very hard to find the right sizes of materials. Why?
1. There are lots of people who will supply aluminum tubing, but very few in the right alloy, right temper, right outside diameter, and right wall thickness. And they will only make tubing to our size requirements if we buy hundreds of meters (literally).
2. There are lots of people who will supply various kinds of plastic rod or tubing, but not in the right diameter (to fit in the case exactly) and with the right wall thickness for the burn. And they will only make tubing to size if we buy hundreds of meters (literally).
I've found some suppliers that can supply small quantities, even having quite a range of sizes, but, as yet, no match - nothing fits exactly.
You see, while I think we make make values, end closures and much else, we cannot machine four feet of aluminum tube to a specific outside diameter, let alone an inside diameter. And I don't believe we can take plastic rod and reduce its thickness, nor can we drill the large hole in it for the gas to pass through. The plastic will likely buckle. Even if we did manage it, we don't want to have to do this for every reload we make. What we want, is a reliable source of the fuel, and then build the motor and values etc., to fit that.
So... as far as I can see the main Chimera challenge now is to get a reliable source of these two materials, in the right specifications, in the right sizes. It's a hunt for suppliers.
Monday, 4 June 2007
So, for Chimera projects we shall be focussing on nitrous oxide (otherwise known as laughing gas or NOS). This is not to be confused with NOX which is a generic term for any single nitrogen atom molecule oxide. NOS got its name from the company that first made nitrous oxide for boosting internal combustion engines.
Sunday, 3 June 2007
The introduction to Hybrid Technology is written by Bill Colburn, the Co-Inventor of the Urbanski-Colburn Valve for simplified hybrid motor construction. Bill also designed, constructed and tested the first Hypergolic Hybrid Motor in June of 1951.
Bill also built the first N2O Hybrid motor using 2 inch tanks (laboratory demonstration tanks), the fore-runner of the consumer High Power Rocket Motors now supplied by both Aerotech and Hypertech. Bill wrote the first Hybrid Propulsion Manual aimed at the field of Experimental Rocketry. This re-written manual is included as part of the SORAC Hybrid Manual.
Friday, 1 June 2007
Sunday, 27 May 2007
Extensive research and development by CTI and eAc has yielded a high tech, low cost rocket motor alternative to the current solid propellant rocket motor. Hybrid motors have several safety advantages over solids. The fuel and oxidizer are isolated from each other until just before ignition, thus eliminating the requirement for a low explosive permit during transportation and storage of rocket motors. HyperTEK® hybrid propulsion system uses a remote fill/fire launch system as well as 100% pyrotechnic free ignition system.
HyperTEK® flight motors consist of three major parts: the oxidizer tank, the injector bell and the fuel grain. The fuel grain is molded from thermoplastic and has an insert-molded silica/phenolic nozzle. This monolithic grain functions as both the fuel and the combustion chamber. Complicated assembly of a reloadable system has been eliminated by incorporating the fuel, nozzle and motor case into one injection molded component. The fuel grain simply screws onto the injector bell prior to flight and the spent fuel grain is unscrewed and disposed of after each flight. J and Original L motors include an injector bell with field interchangeable injector orifices for tailoring the time/thrust profile to the needs of the rocket. Potential applications include small sounding rockets, RATO boosters and more.
Saturday, 26 May 2007
Project Chimera has its own BLOG, this BLOG, but it also has a Zoho Notebook project space, which includes many notebook pages. These pages will expand, and cover different aspects of the design and the project. Over time, I'll be sharing these pages with you so that you can participate. Right now, the most important page is the Design Issues Log (a Google Spreadsheet) and the Research Links (del.icio.us).
Chimera Zoho Project Notebook
Chimera Design Issues Log
Chimera Document Library
You will need a Zoho Account (free) and a Google Account (free) in order to use the Chimera pages and tools. And I recommend getting your own del.icio.us page.
PARS has begun the initial research phase of Project Chimera, code name for hybrid.
Chimera is an attempt, by PARS, to design, build, test and fly, a hybrid rocket rocket motor. It could take years. The first step is some serious learning and research.
The most common hybrid configuration is a rocket engine composed of an inert solid oxidising propellant (for example a plastic) lining a combustion chamber into which an inert gaseous propellant (for example NOX) is injected so as to undergo a strong exothermic reaction to produce hot gas that is emitted through a De Laval nozzle for propulsive purposes. Designing and building such a rocket is non trivial.
/Project Inception May 2007
/Current Phase: Research