Computer Program Design program for Skyrockets

I'm in the process of trying to develop a small BASIC program to
dimension small skyrockets.

I've looked at the various older literature but I would like more
uptodate dimensions specifically for bottle rocket (1oz?), 2oz and 4
oz size skyrockets.

It is hopeful that this program would also allow for design of larger
skyrockets too; but I'm not sure any formula developed would scale
correctly.

I've broken the design down into the following parameters with some
representative values for illustration purposes:


(ID) Inside Case  Diameter  -  Every subsequent dimension will be
based on this dimension("Bore"?)

ID=.375"

(OD) Outside Case Diameter  =  1.5 * ID ??

OD=.5625"

(CTD) Core Tip Diameter = 0.25 * ID ??

CTD = .9375"

(CBD) Core Base diameter   Is this the same diameter as the nozzle
diameter?

(CL)  Core Length- set equal to propellant length  because I define
the heading length as being  a separate parameter.. i suppose heading
length could be subtracted from an overall propelant length?   Also
isn't core length some percentage of the propellant length?

(PL) Propellant Length- does not include Heading thickness or length
above Propellant

(HL) Heading Length (Thickness)  = .75 * ID ??

(NL)  Nozzle Length  = 1.25 * ID  ??

(ND) Nozzle Diameter  - This assume a simple cylindrical nozzle exit

later I would adjust this parameter so I can use CD type nozzles

I notice that on some  skyrocket nozzle ends, there is a kind of 2-
step nozzle where the core base diameter = nozzle diameter, but at teh
end of this nozzle is a kinda larger oriface which seems to correspond
to the ID. I think this 2nd step corresponds to the spindle base
diameter.

The idea of using the above Skyrocket calculator is to also  determine
the tooling dimensions needed.

If anybody would like to help me out with formula for any of the above
please do.

Once I get it working I would be happy to share it with all in the
pyro community.

My idea is to input Case ID, and then let the program calculate all
the other parameters and output them to a text file so I can then use
that as input to a program such as AeroISP or  other program.

The idea of course is to simulate designs before construction.


thanks in advance

terry dean