Design thoughts?

[AfterBurners]

I'm thinking about doing a build thread for a 3-stage rocket, but not the ordinary design where the stages drop off and tumble to the earth, but something where the engines after burnout fall back down. The three engines will be taped together with cellophane tape so when each one ignites the other the tape will melt away. The three engines will be contained within the rocket air frame. Vents will supply the air flow to cool the inside of the air frame. The air frame within the area of the booster engines will be reinforced with a tube coupler to provide strength and keep the air frame from burning up. A coat of epoxy will also be applied to protect the internal air frame. I was thinking maybe a BT80 would be a good size diameter for this project? I still need to put some numbers into RS and see where I'm at, but just a thought? The challenge will be keeping the rocket from nosing over once the two booster engines burnout. I would have to look into the different fin configurations as well.

 

[neil_w]

If the second and third motors are too far recessed into the body, you will get killed by the Krushnic effect. I don't know how much venting you'd need to avoid it. At some point, with enough venting, you'd essentially be building a rack rocket.

 

[kuririn]

This plan for a two stage with drop off booster engine might be helpful:
https://www.spacemodeling.org/jimz/eirp/eirp_28.pdfAnd the original one:
https://www.spacemodeling.org/jimz/eirp/eirp_10.pdfErockets has an upscale version:
https://www.erockets.biz/semroc-flying-model-rocket-kit-sls-lil-augie-ka-38/

 

[AfterBurners]

If the second and third motors are too far recessed into the body, you will get killed by the Krushnic effect. I don't know how much venting you'd need to avoid it. At some point, with enough venting, you'd essentially be building a rack rocket.

The 3rd motor and the last to burn will be at the vent opening.

 

[AfterBurners]

This plan for a two stage with drop off booster engine might be helpful:
https://www.spacemodeling.org/jimz/eirp/eirp_28.pdfAnd the original one:
https://www.spacemodeling.org/jimz/eirp/eirp_10.pdfErockets has an upscale version:
https://www.erockets.biz/semroc-flying-model-rocket-kit-sls-lil-augie-ka-38/

Actually thats very similar to what I had in mind but with 3 stage, but the air frame will be the same diameter, but I could change it?

 

[neil_w]

The 3rd motor and the last to burn will be at the vent opening.

You'd have to draw a picture, I can't, ah, "picture" what you're saying there.