SRM_BETA.XLS
This MS EXCEL spreadsheet was originally written in order to assist in the design of the Kappa series of rocket motors. As it proved to be quite useful and gave good correlation to actual test results, I decided to enhance the spreadsheet and make it available on this web site (as a beta version). Based upon user inputted motor and grain geometry data, the spreadsheet computes Kn over the duration of the burn, generates a pressure-time curve, a thrust-time curve, as well as performance parameters such as total impulse and delivered specific impulse. Although primarily intended for designing motors using KN-Dextrose or KN-Sorbitol propellant, other propellants may be specified with user inputted propellant properties.
Solely for hollow cylindrical grain configurations, such as BATES.
Written by Richard Nakka.
SRM_BETA.ZIP Version: Beta-1 513 kbytes Zipped EXCEL 97 spreadsheet Freeware
CASING.XLS
This is an MS EXCEL spreadsheet that is used to determine the Design Pressure and Burst Pressure of a solid rocket motor casing. Also determines the elastic deformation of the casing under pressure (important for case-bonding consideration). Strength and mechanical properties are supplied for many casing materials such as steels, aluminum alloys, PVC, etc.
Written by Richard Nakka.
CASING.XLS Version 1.03 61kbytes EXCEL 5.0 spreadsheet Freeware
IGNITER.XLS
This is an MS EXCEL spreadsheet that may be used to estimate the chamber pressure that occurs in a rocket motor due to combustion of a pyrotechnic igniter. Use of a properly sized pyro igniter is important for efficient rocket motor design. The motor should reach full operating pressure rapidly without wasting propellant (and thereby reducing Isp). As well, it is important to avoid overpressurization. Although tailored for black powder igniters, this spreadsheet may be used for other pyrotechnic mixtures, as well.
Written by Richard Nakka.
IGNITER.XLS Version 1.00 68kbytes EXCEL 5.0 spreadsheet Freeware
CONVERT
Windows software that converts units for Force, Pressure, Density, Area, Distance, Volume and several other measures. Very convenient and simple to use, highly recommended. Written by Joshua F. Madison. Available for download at Joshua's web site www.joshmadison.com/soft , or download it here:
CONVERT.ZIP Version 4.08 168 kbytes Zipped file Freeware
SOAR
This program predicts the flight performance of a rocket. It calculates parameters such as altitude, velocity, acceleration, drag force, dynamic pressure, Mach number, and is capable of handling single-stage, multi-stage and clustered rockets. Meant to be accurate, the program utilizes efficient professional subroutines for numerical differentiation and integration. Also meant to be versatile and user friendly, it can handle supersonic rockets with a flight ceiling to 100,000 feet. as easily as low altitude model rockets with commercial engines. Runs under DOS only. Written by Richard Nakka.
SOAR.ZIP 187 k DOS Freeware
Data files of Model Rocket Engines, for use with SOAR program. MROCKENG.ZIP 15 k
Data files of the Kappa-DX & Kappa-SB Rocket Motor, for use with SOAR program.
KAPPA.ZIP 2 k 
Data files of the B-200 & C-400 Rocket Motors, for use with SOAR program. ENGINE1.ZIP 1 k
WHOOSH
This program may be of interest to the slightly less adventurous amateur rocketeer -- it predicts the performance of a "pop bottle" rocket (aka "water rocket"). A pop bottle rocket, by the way, is a rocket made from a plastic pop bottle (eg 2 litre) filled with a mixture of water and compressed air (surprising performance!).
Program calculates parameters such as thrust, jet velocity, and pressure, all as a function of time, as well as total impulse and specific impulse. May be used together with SOAR to predicts the flight performance.
Runs under DOS only. Written by Richard Nakka.
Source code (FORTRAN) is available upon request.
WHOOSH.ZIP 37k MSWORD 6.0 documentation DOS Freeware
ROCCAD
& Coefficient of Drag and Centre of Pressure Estimation
This program predicts the altitude a rocket may fly given the performance parameters of the motor and the physical characteristics of the rocket. The program also determines the optimum weight of a rocket to achieve maximum altitude. Additionally, the program can estimate the coefficient of drag (Cd) and the centre of pressure (Cp) of a rocket, based on the rocket's geometry. Includes performance parameters for the PVC "G" and PVC "H" motors.
Runs under DOS only. Written by Charles D. Knight.
ROCCAD.ZIP 169 k DOS Freeware
GUIPEP
This program provides a user friendly interface to run the PROPEP propellant evaluation program. PROPEP is a program that determines the chemical equilibrium composition for the combustion of a solid or liquid rocket propellant. Additionally, it determines rocket performance parameters such as Isp and C*, and nozzle design parameters.
Runs under Windows. Written by Arthur J. Lekstutis, GUIPEP is available for download at Arthur's web site, which also has a link to PROPEP.
GUIPEP and PROPEP MS Windows For free distribution
Expanded data file (pepcoded.daf) for the PROPEP program. Includes entries for Dextrose, Sorbitol, Charcoal, Asphalt, and Paraffin.
pepcoded.zip Zipped text file 23 kb
THERMCAS
A thermal analysis package that determines the temperature distribution through the thickness of a motor casing wall that results from convective heating due to propellant combustion and resulting gas flow. The package consists of DOS executable file which outputs a table of results which may be copied into a companion EXCEL spreadsheet for plotting. In addition, the spreadsheet contains thermal and material properties required as input data, as well as a calculator for determining the required heat transfer convection coefficient.
Runs under DOS only. Written by Richard Nakka.
THERMCAS.ZIP 62k DOS Freeware
PARAPAT.XLS
This MS EXCEL spreadsheet may be used to create a flat pattern for a parachute gore. A gore is an individual panel that, when stitched together with adjacent gores, forms the canopy of a parachute. The user inputs the basic parachute diameter, as well as the number of gores desired (minimum of 4). The spreadsheet creates a table of coordinates as well as a plot of a single gore. When assembled, the parachute canopy is semi-ellipsoidal in shape (a "flattened" hemisphere). This fom of canopy is more efficient than a hemispherical canopy, in that less material is required to provide equal drag.
Written by Richard Nakka.
PARAPAT.XLS Version 1.00 42kbytes EXCEL 97spreadsheet Freeware
LOADCELL.XLS
A relatively simple-to-make beam-type loadcell may be designed by use of this Excel spreadsheet. The user specifies the dimensions of the loadcell body (basically, a rectangular block of metal) and the size of hole to be drilled through the body, in order to achieve the desired load capacity. The only other materials required are one or two strain gages, and suitable adhesive for mounting such.
Written by Richard Nakka.
LOADCELL.XLS Version 1.00 76kbytes EXCEL 97spreadsheet Freeware
