Motor Requirements

Motor Design Requirements

Overall Design Data

A case bonded finocyl motor

Chamber pressure is expected to be between 800 PSI +/- 200 PSI

Port area to nozzle area ratio can not be less that 1.75; a ratio of 2.0 or above is preferred

Mass Flux should be less than 1.75

Propellant must have a demonstrated large margin for error.

A flame color is of no concern, motor performance will be the driving criteria.

A flat motor curve is expected. Other thrust curves will be considered should flight dynamics indicate.

Booster Motor

Desired initial thrust is 6000 to 8000 pounds

Motor ID: 7.50" OD: 8.000"

Total Impulse 100,000 NS to 125,000 NS.

Motor Length is up to the designer; Length of 72" +/- 18" is expected

Sustainer Motor

The sustainer motor will be a scaled up version of the booster motor.

Motor ID: 12.00" OD: 12.750"

Total Impulse 400,000 NS to 500,000 NS

Case Length 108"; Propellant Length: To be determined

Motor Development Scheme
To be determined.

Propellant

Several propellant formulations are currently under investigation.

At this time Honey Badger Slow is being used for Burnsim motor testing. I would like to credit the developer of this propellant, but can't seem to locate him.

AlumaFlame: Is the clear front runner at this time. AlumaFlame is TeamNumb's standard propellant. Alex McLaughlin came up with it years ago.

Amarillo Blue: Initial BurnSim results show this propellant to have a higher than desired burn rate.

Unknown Blue: This propellant used by Dave Leininger in Locomotive Breath looks great in flight, no data is available to perform an evaluation at this time.

White Lightning (clone), and Wayside White seem to have potential but more data is needed.

Any clones of Warp9, Kosdon Fast, or V-Max type propellants would be awesome, but will not be considered as they are deemed to aggressive,

Preliminary Motor Designs

Booster Motors 8" Q-18200

Sustainer Motor 12" S-12900

Burnsim data files

There are currently a large number of Burnsim motor files for this project.

All of them should be considered an educated guess, and rough tests.

No files are ready for prime time at this point.

What is BurnSim?

BurnSim is a solid rocket steady-state ballistic simulation software package for the Windows platform. In a nutshell, input your motor, nozzle and propellant characteristics and BurnSim calculates the Kn through the burn and predicts estimated chamber pressure and motor performance. Once your motor design is in BurnSim, you can tweak the parameters such as nozzle diameter or grain core diameter and instantly see how the Kn, chamber pressure, and motor thrust is affected. BurnSim will also optimize your nozzle design.

CATO, an acronym used in rocketry, for Catastrophe At Take Off—the catastrophic failure of a rocket engine.

Page Revision 002, for previous version see Revision 001