1. Hybrid Rocket Combustion Process & Nozzle John Chambers

2. Hybrid Combustion Oxygen disassociates from Nitrogen in an exothermic process Gaseous oxygen is now present and rapidly combusts the solid fuel Combustion products are mainly CO 2 and H 2 0 Flame Temperature ~3300 K Fuel Grain Wall Temperature ~1000 K Nozzle Throat Temperature ~3000 K

3. Nozzle The function of the nozzle is to accelerate the combustion products to very high speeds and expel them to produce thrust Thrust = mass flow rate * exit velocity +(exit pressure – back pressure) * area

4. Nozzle Composed of a subsonic and a supersonic nozzle, connected at the nozzle throat The flow must reach Mach 1 at the throat

5. Nozzle Design Method of characteristics is used to design a nozzle of minimum length for shock-free, isentropic flow

6. Nozzle Materials The combination of high temperature and high velocity flow will quickly erode nearly all materials Graphite is one of the few materials that will stand up to these conditions for more than a few seconds Throat erosion will alter the geometry of the nozzle and cause poor performance

7. References Nozzle diagram: –http://www.engapplets.vt.edu/fluids/CDnozzle/cdinfo.html