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Nozzle Design Resource

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nonameworks

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Hello,

This is my first post, I searched a little bit and haven't found anything about nozzles anywhere. I have been having trouble finding resources for nozzle design. I have found lot's of equations that could be used but no practical information such as what materials should be used. I found a textbook on google books that looks great found here: http://tinyurl.com/cmxlvv.

The information that I want to know is everything that I need to actually build the nozzle. I would like to read about the small details of the effect defects could have, and what little things I can do to improve it. But I want the information to be generic so that I can use it with different kinds of propellants. I am hoping to get this information for free, otherwise I may purchase that book. Thank you in advance for your assistance.
 

WiK

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This will probably get more attention in the Propulsion section, so I've moved it for you.

I think I'm right in saying that Rocket Propulsion Elements is one of *the* books to have if you're at all interested in rocket motors. I've even got a copy somewhere, haven't read it though. :rolleyes:

Phil
 

ben_ullman

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$50 Terry Mcreary's Book

Experimental Composite Propellants. Worth every penny. De shows you how to derive the informations and equations manually and includes software to help you do it more easily.

Ben
 

bobkrech

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High power hobby rocket nozzles are typically made from filled-phenolic resin or graphite. Filled-Phenolic resin nozzles will exhibit some erosion which may or may not be important during the several seconds of the motor burn. Graphite typically does not erode.

Aerotech and Cesaroni typically use filled-phenolic resin nozzles. AMW, Loki, and several others used graphite.

This is a typical AT nozzle design made of glass-filled phenolic resin for a hobby rocket motor. http://www.rocketmotorparts.com/engdrawings/rcs_01670_nozzle_dwg.pdf For practical purposes, a 120 degree full-angle conical convergent section (subsonic combustion chamber side) and a 30 degree full-angle conical expansion nozzle (supersonic exhaust side) yields a inexpensive, simple-to-manufacture nozzle that provide good performance and minimum length and weight. Larger professional rocket with regenerative cooling or Carbon-Carbon nozzles employ the method of characterics to optimize nozzle length, mass and efficiency but it's simply not worth the time and expense for hobby rocket motors.

More important is the need to determine the Kn of the propellant composition to determine the throat diameter. If you make the throat area too large, (Kn is too small) the motor may not light and/or you will get poor perfromance. If you make the throat too small, Kn is too large, the motor will overpressurize and fail the casing.

You also need to run a program like ProPEP to determine the optimum area expansion ratio to determine the nozzle exit area for a given throat diameter. If the area ratio is too small or too large, the specific impulse is not optimized and the motor underperforms.

Sutton is a good book to start with, and has a large number of references that you will need to read if you really want to know the gory details of nozzle design.

Bob
 

nonameworks

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Thank you very much for your replies. Unfortunately I won't be able to let you know how everything works out because I am too busy for a little while. But I really appreciate your help and I will put it to good use. I'll try not to ask a million questions but the people here already appear to be well educated. But you left me with a huge question, how do I determine the Kn value experimentally. Don't worry about safety or practicality here, I am simply doing this for a study on the efficiency of readily available fuels as rocket fuel.
 
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