open rocket error

[ILoveRocket]

Hi, I ran an open rocket simulation using Richard Nakka's spreadsheet. The value was set in data and kn and the value was output throughout tap. And I entered that value into the engine editor and transferred the information to the open rocket. However, the simulation showed an apogee of 1290 meters. But since I only used about 80 grams of fuel, that's not possible. I can't find where it went wrong. Please find the problem.

 

[wonderboy]

I tried loading your open rocket file but got several errors.


What did load only weighed less than 1/2 pound (0.487 pounds). On a G128, that's gonna go about as predicted (really really high)

I was going to make a list of things that seem out of the ordinary with this file, but it seems everything is unusual for a rocket this size, including:
-PVC main body tube
-Cardboard fins
-No centering rings
-No recovery system

I'm not trying to sound negative here, but it seems like perhaps you are very new to this based on some of the material choices here. If you take a look at some commercially available basic kits, you'll get a better idea of how the construction works. Pick something you like from Estes for example, and then google search for the open rocket sim file for that model. It will give you a good idea of more typical construction of a rocket this size.

Post back here if you've got more questions on how to do things.

 

[Hobie1dog]

to the forum

 

[neil_w]

But since I only used about 80 grams of fuel, that's not possible.

Maybe I'm just ignorant, but... why is it not possible? You're entered a small and light rocket and shoving a G into it.

I would agree with @wonderboy that the materials of the various components seem like they are most likely incorrect, but you have entered what appears to be (on paper) a valid rocket design and, as far as I can tell, you're getting valid sim results.

I tried loading your open rocket file but got several errors.

It appears you are running the old version of OR, which is why you're getting those errors. Please update to 22.02!

 

[wonderboy]

It appears you are running the old version of OR, which is why you're getting those errors. Please update to 22.02

Got it! Yup, I was still running the 22.02 Beta 05. That fixed it!