Medusa Nozzle Throats for 1 grain?

[ckrokosz]

How many throat openings should we use on a 1 grain motor; bought a medusa nozzle, and have to drill throats ourselfes

 

[COrocket]

Are you using an RCS/Aerotech fuel grain? There are motor assembly drawings on the Aerotech website that show the Medusa nozzle configuration for various reloads. If you are making your own motors, none of that information will be relevant.

 

[0011001100]

Are you recreating a commercial motor or designing your own? If you're designing your own then you want to total throat area to be equivalent to what you designed it to. As for the number of throats to drill, that would depend on the total area needed. For a 1 grain you probably only need the central hole drilled anyways as the throat will be small to keep the KN in range.

 

[FredA]

Same way you pick the throat on a single-hole nozzle - by area to yield the desired Kn.

Seems like a very odd question.
Doesn't demonstrate basic understanding.

One post....R U a Bot?

 

[tfish]

AT 54-426 old style 1 grain motors...


I115W, I117FJ, I215R, center hole only .228"

I229T, center hole only .298

I599 center hole .228", two outter holes .228" (also)

check my numbers to be sure! https://www.rocketmotorparts.com/page/motor-assembly-drawings

Tony

 

[AeroTech]

How many throat openings should we use on a 1 grain motor; bought a medusa nozzle, and have to drill throats ourselfes

Depends on the grain dimensions and propellant type, Medusa nozzle part number (54, 75 or 98mm) and average pressure desired.

 

[Handeman]

Whatever the AREA of the nozzle opening that you need for your propellant, that's what the total area of the holes drilled in the Medusa nozzle has to be.

For a single grain, you probably only need to drill the center hole of the medusa nozzle to the right size. Usually the center nozzle and 3 or 6 of the outer ones are drilled.