Ramjet Rocket

To separate my ramjet project from my posts highlighting religious stupidity i will copy the posts to this page as one continuous thread chronologically with the newest post on the top.

Post 4 – 05.09.07

Failure, yet another attempt wasted. I am starting to think that i wont be able to manufacture the body tube from alumina.

I tried cutting it with a CO2 laser but the temperature gradient created enough internal stress in the material to blow it apart.

These are the biggest surviving pieces i will have to re consider making the body tube in a different material, it seams thin walled alumina is hell to work with.

I dont know how to solve this issue since the temperature in the combustor will reach about 2000F, and steel just wont cut it, and active cooling is out of the question since it will be to heavy and complicated.

Back to the drawing board i guess.

Post 3 – 14.08.07

Ramjet body manufacturing problem solved!

Lets put it this way manufacturing ceramic alumina is a bitch, this material is hard as hell. I have made repeated (22) attempts at cutting and grinding the main body part for the ramjet, no luck at all.

Uncured alumina is brittle, and not very strong, its a pain to deal with, also thin walled ceramic alumina when fired requires accurate temperature control, if the temperature goes up to fast it literally explodes.

The solution is to cast the still liquid alumina straight from the melting furnace to an oven with a rotational form the form is already fitted with the restraining ring seen at the end of the body holding the nozzle. i did a test yesterday it seamed to work fine, since it goes straight into the firing oven i don’t have to fully cool the piece so it doesn’t get the internal tension before firing is complete.

Its perfectly formed and strong as hell. I will carry out pressure testing hopefully this week.

I still have to manufacture the intake and the nozzle, since they are thicker i schould be able to rough cast them and grind them to the desired dimensions.

I wonder if the process of moving it straight to the curing oven makes it less brittle? it seams more resistant somehow? i banged the tube with a hammer without any bad effects to the body tube what so ever.

Post 2

I started this project inspired after a visit to a site by Glen Ohlson

I have no ideas how many proto-designs and initial main ideas i have gone through, but i think i have closed the main design parameters down they where.

Prototype 1.

1. Easy manufacture
2. Re usable
3. Exchangeable parts
4. Liquid fuel
5. Mach 2

Prototype 2. in addition to the above

1. Variable geometry
2. Active guidance
3. Mach 5

I have decided on a square body design, its easier than a round body even though its slightly less aerodynamic.

The air intake will be blocked by a gate operated by the air pressure as the rocket moves through the air.

At full “rocket trottle” the pressure inside the ramjet body is higher than the airspeed pressure, once the rocket reaches a set speed mach 1,5 the rocket throttle goes to idle.

The airspeed will push the Gate back and the ramjet fuel is injected.

There is no need for a flame holder since the rocket will remain on idle, igniting the fuel for the duration of the flight.

Special problems:

There are 2 major problems with ramjet as a means of propulsion, 1 it needs high speed to work in the first place. And secondly at high mach speeds things get really hot.

TO solve the first problem i have 2 modes of operation for the rocket, one as a pure rocket (air intake gates closed) and secondly as a combination rocket ramjet (air intake gates open).

The fuel will be methanol or ethanol, since ordinary petroleum based fuel carbonizes at high temperatures.

I found a forum pulse-jets.com That seams pretty active and i will take some time to go through the information there, i also found out that Glen who inspired this attempt frequent this page.

I am impressed by all the attempts made by this community, it seams like the only thing they lack is time for their projects and funds, luckily i don’t suffer from any such restraints.

I will post updates as progress is made, but its a hell of a lot of math and design to go through before a functional version is ready for launch.

Post 1

So I finally started my own blogg my very own place to bitch about whatever I want.

I mean, every other ashole on the planet has their own bitching place. So why not me. I plan to log some of the experiments and activities i intend to carry out. I will remain anonymous, because from what I’ve seen happening to people experimenting in similar fields, and i think there are regulations that aim to limit such exploration and activities.
Of course, I seriously disagree with such regulations since I can’t understand why the fuck scientific endeavours. In certain areas should be exclusively government-controlled? actually across the planet government seems to forget that they are our employees who we have tasked to provide a few basic things such as roads basic education. Healthcare and security for people and property. government-controlled activities are inherently wasteful, ineffective and costly. So I don’t want them to do anything other than what we asked them to do.

My first experiment is actually inspired by a web page by Glenn Ohlson that has done some research into using a ramjet rocket as a launch platform. This is an intriguing idea, and he has certainly has certainly put thought and effort into this idea but nothing I can find has ever been produced that could be considered flight worthy. One of the main problems faced by such an approach is that a ramjet isnt very effective at low speeds. In fact, it’s not very efficient until you reach speeds of about mach 3. So before you can actually use the ramjet stage. We have to accelerate the device up to a speed where the ramjet can start to produce useful thrust. i have seen quite a few different approaches to this problem everything from guns. To rubber band launchers seems to have been explored.

My approach will test. if It is possible to operate a rocket with different flight modes it will start as a rocket and accelerate to about twice the speed of sound, were it will switch to ramjet mode for the remaining duration of the fight.

Luckily, I am not bound by financial time restrictions, and I expect to spend four years to complete the device.