Thursday, 26 March 2009

Failed test

I tested the rocket and here is the video of the test

http://www.youtube.com/watch?v=6zIoVpmVAuw

I am trying to find out what went wrong. I thnk the nozzle throat dia is too small or I am not getting the rocket hot enough to split the NOS. I am waiting for the fuel grain to be drilled out and I'll try again

Cheers

Friday, 20 March 2009

March 20th Quick update

After the first rocket test it was obvious that I needed to have a larger fuel grain for a longer burn time. I managed to find a copy of a spreadsheet to help in rocket design and made a rocket motor 41mm dia by 400mm long using the original exit nozzle

By adjusting the injector from 1mm through to 1.75mm I can adjust the thrust from 7.5lbs to 20lbs. All I need to do is test it.

I have made a car (Pics coming) and I fitted the rocket and 800cc NOS bottle and tried testing the rocket but gas from the bottle made its way into the rocket and blew it out. This confirms my original fears that a horizontal bottle wont work in a shaky car. I will need to ensure the NOS is kept in its liquid form by the use of of an N2 pressure system. This means either a small N2 tank and a regulator or a small hydraulic pump. The nos has to be in an accumulator with a sliding piston to keep the pressure medium away from the NOS.

I will post picks of the tests and designs later

So for now all I can do is test the rocket motor on the stand using the bottle in the vertical position until the new pressure system is designed