Heat Transfer Revisited – BRR

Carl from Brittish Reaction Research has posted a new update on his rocket engine project and is looking for some guidance on his heat transfer calculations.

This post is going to deal with some tentative calculations on the quantity of heat transferred through the walls of a rocket nozzle I am building. This study is part of my ongoing engine project. To be more specific, I’m interested in finding out how much coolant flow will be required to safely absorb the heat generated by the combustion gases.

Carl runs through the series of calculations required in detail which can be found here, worth a read, it is really easy to follow and if you can help him out, do so!

If you have got this far, thank you for staying with it. Perhaps now you would allow me one last indulgence and tell me if you think I have got it somewhere near right!

Help out a fellow amateur rocket engineer!

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Oven Ready – BRR

Carl from British Reaction Research posts a new update on his oven progress for heat treating his aluminium tube bundled thrust chamber.

The tube bundle thrust chamber will be a weldment composed of 6082 and 6063 elements. In order to solution treat or artificially age this I have to raise it to a temperature of 525 degrees Celsius +/- 10 degrees and hold that for a specified time.

Using a repurposed pottery kiln, and custom temperature measurement system, the test proved successful.

After 25 minutes of running the 450 degree mark was breached and after 35 minutes a temperature of 520 degrees was attained. This finally settled down at 530 degrees and stayed there, give or take a degree either way.
I didn’t think this was too bad at all, what with my initial misgivings about the accuracy of the control system and that the dial had been set quite roughly.

Patently Obvious

Brittish Reaction Research continues down the road of a tube bundled rocket engine, in this update, finding a patent from 1932 describing the tube bundled process, although for the production of power, not a rocket engine.

My internet research frequently involves trawling through old patent documents. These often provide a wealth of information, and I’d like to share some of this with you now.

Great Britain patent 376,974 was applied for in August 1931 by the Swiss engineering firm Brown Boveri. Granted in August 1932, it has as it’s object “Improvements in and Relating to Combustion Chambers”.

This is one of the earliest references I can find depicting a combustion chamber made from tubular elements to allow a coolant to be circulated through.

Continue reading the full update here.

British Reaction Research

I was recently pointed to this blog, British Reaction Research, detailing the progress of blogger and rocket engineer, Carl, as he builds a liquid-fueled rocket engine.
Not just your normal amateur liquid rocket engine, Carl is attempting to make an aluminium tube bundled engine. For those not familiar with this construction, the engine is built up of multiple tubes, shaped to achieve the desired coolant velocity and usually brazed together to form the rocket engine.

J2 engine construction (Credit: NASA)

The latest update delves into the testing process in order to use these tubes in the bundle.

I have been looking into the forces required to break a hypothetical aluminium test piece, in order to come up with a set of dimensions that keeps the pressure needed within acceptably safe limits.

Make sure to follow the British Reaction Research blog as there is a ton of information in there all amateur builders will find very useful, and stay up to date with the latest on the tube bundled engine!