Gentlemen:
A summary of key technical results and conclusions from my High Power Rocketry Magazine tech article "Departures from Ideal Performance for
Conical Nozzles and Bell Nozzles, Straight-Cut Throats and Rounded
Throats" is now on the High Power Rocketry web site at:
www.hprmagazine.com/technical
The summary equations and a summary plot of nozzle thrust coefficient versus straight-cut throat L/D are included. The summary plot shows the large jump in nozzle thrust coefficient for straight-cut throat L/D's < 0.45. I recommend the following design criteria; straight-cut throat L/D <= 0.40, for margin to make sure that the jump in performance shown on the summary plot is obtained.
Based on a nozzle survey included in the tech article this increase in nozzle thrust coefficient has the potential to increase the thrust, total impulse and specific impulse of most high power solid rocket motors, and almost all experimental/amateur solid rocket motors by 3.5% to 8%, a significant across-the-board increase in performance.
Chuck Rogers snipped-for-privacy@aol.com
A summary of key technical results and conclusions from my High Power Rocketry Magazine tech article "Departures from Ideal Performance for
www.hprmagazine.com/technical
The summary equations and a summary plot of nozzle thrust coefficient versus straight-cut throat L/D are included. The summary plot shows the large jump in nozzle thrust coefficient for straight-cut throat L/D's < 0.45. I recommend the following design criteria; straight-cut throat L/D <= 0.40, for margin to make sure that the jump in performance shown on the summary plot is obtained.
Based on a nozzle survey included in the tech article this increase in nozzle thrust coefficient has the potential to increase the thrust, total impulse and specific impulse of most high power solid rocket motors, and almost all experimental/amateur solid rocket motors by 3.5% to 8%, a significant across-the-board increase in performance.
Chuck Rogers snipped-for-privacy@aol.com