Ye Olde Rocket Forum

Go Back   Ye Olde Rocket Forum > Work Bench > Projects
User Name
Password
Auctions Register FAQ Members List Calendar Today's Posts Search Mark Forums Read


Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 08-21-2022, 12:07 PM
HenryMac's Avatar
HenryMac HenryMac is offline
When In Doubt, Build Hell-For-Stout
 
Join Date: Feb 2020
Location: Central Colorado
Posts: 174
Default A Finless Rocket Named Thunk!

Ever seen a marine signal flare? It's a road flare and a rocket and a parachute, all in one tidy little package. The first so-called “tube” parachute flare rocket, named IKAROS, was introduced by Hansson of Sweden in 1959.

Ikaros video: https://www.youtube.com/watch?v=uA4bR3U4hmI

This finless rocket design uses a technique called induction tube stabilization. This technique of using entrained air mixed with the rocket motors exhaust provides a fin-like stabilizing effect.

I wanted to see if I could build a rocket that uses this technique.

One issue is that when the motor thrust stops.... so does the stabilization. Which means during the coasting phase the rocket would be unstable.

To address this issue I placed canted spin tabs on the rocket to induce roll. This should stabilize the rocket if the spin rate is sufficient.

Since the rocket will be spinning I didn't want to use a launch rod or launch rail that would restrict the spinning. I was also concerned about adding launch lugs that would make the rocket unbalanced while spinning. The decision was made to use a launch silo made from 2" pvc pipe.

We launched the rocket on a D12-5. It flew stable and was recovered undamaged.

Launch Video https://www.youtube.com/watch?v=fJtzJEXJy1s
Attached Thumbnails
Click image for larger version

Name:  Thunk Rocket Dwg Sheet 01 of 12 Rev 05.jpg
Views: 42
Size:  115.3 KB  Click image for larger version

Name:  2022-07-26 013 Thunk.JPG
Views: 18
Size:  269.1 KB  Click image for larger version

Name:  2022-07-26 007 Thunk.jpg
Views: 21
Size:  52.9 KB  Click image for larger version

Name:  2022-07-26 006 Thunk.jpg
Views: 19
Size:  118.5 KB  Click image for larger version

Name:  2022-07-26 002 Thunk Clears Silo.jpg
Views: 18
Size:  120.6 KB  Click image for larger version

Name:  001a.JPG
Views: 24
Size:  174.1 KB  Click image for larger version

Name:  001.JPG
Views: 22
Size:  215.8 KB  Click image for larger version

Name:  004.JPG
Views: 36
Size:  169.1 KB  Click image for larger version

Name:  2022-03-20 As Built Open Rocket Flight Simulation.jpg
Views: 22
Size:  141.1 KB  Click image for larger version

Name:  2022-07-26 018 Thunk.JPG
Views: 25
Size:  252.2 KB  

__________________
John Simmons a.k.a. "Lakeroadster"
NAR 113985
My Fleet with Build Data: Lakeroadster's Rocket Shop
Reply With Quote
  #2  
Old 08-21-2022, 12:21 PM
Ltvscout Ltvscout is offline
Ye Olde Rocket Shoppe
 
Join Date: Jun 2004
Location: Milwaukee, WI
Posts: 6,474
Default

Wow, very cool and unique!
__________________
Scott D. Hansen
Ye Olde Rocket Shoppe - Your One Stop BAR Shoppe!
Ye Olde Rocket Plans - OOP Rocket Plans From 38 Companies!
Ye Olde Rocket Forum
WOOSH NAR Section #558
Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump



All times are GMT -5. The time now is 02:36 AM.


Powered by: vBulletin Version 3.0.7
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Ye Olde Rocket Shoppe © 1998-2024