new ThrustCurve.org is live

[T34zac]

Would it be possible to make a "cluster addition" tool? To get a thrust curve for a combination of motors for a cluster rocket. Similar to this tool:https://www.rocketreviews.com/combine-motors.html

 

[Tobor]

John,
Many thanks for all the time and effort you have put into this project. The value you have added to the rocket community is amazing. Well done sir.

 

[JohnCoker]

Would it be possible to make a "cluster addition" tool? To get a thrust curve for a combination of motors for a cluster rocket. Similar to this tool:https://www.rocketreviews.com/combine-motors.html

Yes, it would be possible. What would it do that the one you linked doesn't, though? Plus, RockSim and OpenRock both have the ability to specify clusters and staging already.

 

[T34zac]

Yes, it would be possible. What would it do that the one you linked doesn't, though? Plus, RockSim and OpenRock both have the ability to specify clusters and staging already.

Well ease of use on that tool leaves something to be desired, finding the right motor is like trying to find a needle in a haystack. Both OpenRocket and RockSim handle staging and clusters nicely, but it would be nice to have a quick and easy tool for getting a thrustcurve and total impulse/thrust for a clustered or staged rocket.

 

[JohnCoker]

Well ease of use on that tool leaves something to be desired, finding the right motor is like trying to find a needle in a haystack.

True; a thousand items in a drop-down box isn't easy to use.

but it would be nice to have a quick and easy tool for getting a thrustcurve and total impulse/thrust for a clustered or staged rocket

So it's the thrust curve chart and stats that are most valuable?

There's a lot of good work on RocketReviews and it seems to be actively maintained. It's a shame if there's a lot of duplicated effort.

 

[JohnCoker]

I have added the ability to search by motor case and done some cleanup on the motor cases to make them more consistent. Note that for both propellant and motor case, if you select the manufacturer first, it will limit the list to only those entries. Also, for motor case, if you select the diameter, it will also limit the list. (Otherwise, the lists are unmanageably long.)

 

[Neutron95]

One extremely minor thing that I've noticed is that in the motor browser, motor cases seem to be in alphabetical instead of numerical order. It's mostly just a minor annoyance with the Aerotech lineup.

 

[JohnCoker]

One extremely minor thing that I've noticed is that in the motor browser, motor cases seem to be in alphabetical instead of numerical order.

OK, that should be fixed now; sorting is smarter about embedded numbers (all numbers actually).

 

[mbeels]

I do really like some of these recent improvements (especially the motor case filters). They're great.

I did notice that the Loki G94 is listed as for the 38/240 case, but it is actually a 38/120 motor. Is there a better place to report minor issues like this?

 

[JohnCoker]

I did notice that the Loki G94 is listed as for the 38/240 case, but it is actually a 38/120 motor. Is there a better place to report minor issues like this?

Thanks; I fixed it. Maybe I should add a "report incorrect info" link on the motor pages.

 

[teepot]

I have a question. I'm looking at the difference in altitude for 3" vs 4" rockets. For example a 3' at 80 ounces on a J425 goes to almost 3700' but a 4" of the same weight and motor only makes 2700'. Is the drag of a 4" that much greater. I find the altitude difference hard to understand. How about a little enlightenment.

 

[Neutron95]

I have a question. I'm looking at the difference in altitude for 3" vs 4" rockets. For example a 3' at 80 ounces on a J425 goes to almost 3700' but a 4" of the same weight and motor only makes 2700'. Is the drag of a 4" that much greater. I find the altitude difference hard to understand. How about a little enlightenment.

Drag is going to scale roughly with frontal area, which is going to scale with the square of the linear change. So a 4" rocket is 1.333 times wider, which means it will have -1.777 times more surface area and drag.

 

[JohnCoker]

Plus, drag is proportional to the square of the velocity, so you'll see much bigger effects in motors that push the airframe faster.
I wrote this article on flight physics if you're interested in the details.

 

[teepot]

Plus, drag is proportional to the square of the velocity, so you'll see much bigger effects in motors that push the airframe faster.
I wrote this article on flight physics if you're interested in the details.

thanks. I read it and some others.