Aerotech N3300 Thrust Curve data

[astro-megan]

Looking to fly a N3300R in the next couple months and have noticed that there's some differences in the thrust curve shown by the manufacturer and the data that I currently find on thrustcurve.org. As far as my sims are concerned, I'm wondering what to trust. the sim is currently using the thrustcurve.org data, but I'm aiming for a certain flight profile and what to make sure the data I'm using is good. Can anyone speak to how these motors perform when compared with simulation data in OpenRocket or RasAERO? I have come across some posts online indicating that the test data used to create the thrust curve on thrustcurve.org more aligns with flight performance, but if anyone has any other experience to add I'd love to hear it.

These are the links with the thrust curves I'm looking at:
https://www.thrustcurve.org/motors/AeroTech/N3300R/
https://aerotech-rocketry.com/products/product_4a713877-dd26-42a3-82a2-adf6b4b498f1

 

[mikec]

Did you see this note on thrustcurve from the submitter, Charles Barker?

There are two very different thrust curves for the AT N3300R floating around online. They have roughly the same net impulse, but the shapes of the curves are quite different in ways that make it difficult to predict launch rail velocity. I believe the source of the discrepancy is that the curve in the Tripoli test report doesn't match the curve in the AeroTech catalog. The test report shows an initial thrust around 800 lbs, level for most of the burn; the AT catalog depicts an initial thrust around 500 lbs, rising to over 900 lbs after ~2 seconds. That makes a huge difference when simulating the rail velocity for a heavy rocket.

I asked Karl Bauman at AT about the discrepancy in an email and he said: "I would use the curve depicted on the TMT motor testing report, it is within 1% of the value we obtained during motor testing."

That being the case, I based my RASP file submission on the data in the test report here: http://www.aerotech-rocketry.com/uploads/8b644cd4-9eb7-4eb4-a834-23590baca387_n3300r_tra_cert.pdf

This report also seems to better reflect real flight data.

Here's a good link to the TRA report: https://d11fdyfhxcs9cr.cloudfront.net/templates/170652/myimages/n3300r_p_tra_cert_1642718898263.pdf

 

[jmasterj]

The TMT certification document matches the thrustcurve data (the other way around, rather). Can't tell you any more than that, personally.

 

[pathtouch]

Here’s the thrust curve note others have referenced.