Search found 11 matches

by SlapHazard
Tue Sep 25, 2018 8:17 am
Forum: Ramjet forum
Topic: Subsonic Ramjet Design Project
Replies: 15
Views: 3675

Re: Subsonic Ramjet Design Project

I've revised the design of the fuel injection to fit these new changes, as is illustrated below. v8-inj.PNG The shape of the actual spray nozzle depends on whether I use kerosene or a propane-butane mix, which in turn depends on the heat and thrust generated by the fuel. Flame temperature is importa...
by SlapHazard
Mon Sep 17, 2018 2:30 am
Forum: Ramjet forum
Topic: Subsonic Ramjet Design Project
Replies: 15
Views: 3675

Re: Subsonic Ramjet Design Project

Quick update: according to the resource on ramjets, the length of the combustion chamber should be about 3 times the diameter of the inlet. From its area I calculated the inlet's effective diameter (the diameter of a circle with the same area) and set the combustion chamber's length to be 3 times th...
by SlapHazard
Fri Sep 14, 2018 5:16 am
Forum: Ramjet forum
Topic: Subsonic Ramjet Design Project
Replies: 15
Views: 3675

Re: Subsonic Ramjet Design Project

Aside from what you can see in the attached image, I have also altered the flameholder by slightly increasing the width of each gutter and increasing the length to equal the width. The angle of each gutter is now 45 degrees. The cooling duct, doubling as a means by which to attach the engine to a py...
by SlapHazard
Tue Sep 11, 2018 5:40 am
Forum: Ramjet forum
Topic: Subsonic Ramjet Design Project
Replies: 15
Views: 3675

Re: Subsonic Ramjet Design Project

Hi, thanks for your interest! As for your questions, I can tell you that: The area of the inlet is 19.6 cm^2 and the area of the nozzle is 28.9 cm^2 I'm a little unsure as to what you mean here, but the total area taken up by the gutters (including the empty space behind them) is about 6.9 cm^3- eac...
by SlapHazard
Sat Sep 01, 2018 8:09 am
Forum: Ramjet forum
Topic: Subsonic Ramjet Design Project
Replies: 15
Views: 3675

Re: Subsonic Ramjet Design Project

Also, I should point out that I'm planning to use 1mm thick mild steel for construction, the engine is about 10cm tall and 62cm long. I've known the material to be very stiff when cut into dimensions like this, even more so when welded to other parts. Do you think this would mitigate the issue of dr...
by SlapHazard
Tue Aug 28, 2018 12:40 am
Forum: Ramjet forum
Topic: Subsonic Ramjet Design Project
Replies: 15
Views: 3675

Re: Subsonic Ramjet Design Project

I should mention that there are some minor changes I have made which aren't shown in the recent diagrams- the flameholder gutters are now, from a top-down plan view, 1cm*1cm and have an angle of 90 degrees.
fh.PNG
fh.PNG (3.71 KiB) Viewed 2536 times
Does this seem alright to you?
by SlapHazard
Mon Aug 27, 2018 1:19 pm
Forum: Ramjet forum
Topic: Subsonic Ramjet Design Project
Replies: 15
Views: 3675

Re: Subsonic Ramjet Design Project

Thanks for the tip on that. What do you think I should change about the shape of the engine duct itself?
by SlapHazard
Fri Aug 24, 2018 11:11 am
Forum: Ramjet forum
Topic: Subsonic Ramjet Design Project
Replies: 15
Views: 3675

Re: Subsonic Ramjet Design Project

What else would you suggest I change?
by SlapHazard
Thu Aug 23, 2018 5:35 am
Forum: Ramjet forum
Topic: Subsonic Ramjet Design Project
Replies: 15
Views: 3675

Re: Subsonic Ramjet Design Project

diffuser2.PNG
(8.04 KiB) Not downloaded yet
This is the latest iteration of the design.
by SlapHazard
Sat Aug 18, 2018 9:28 am
Forum: Ramjet forum
Topic: Subsonic Ramjet Design Project
Replies: 15
Views: 3675

Re: Subsonic Ramjet Design Project

diagram.png
(2.62 KiB) Not downloaded yet
Here is a cut-away diagrammatic view of the engine's latest iteration, with the fuel injection, flame holder, spark plug and cooling duct visible.
by SlapHazard
Fri Aug 17, 2018 4:01 am
Forum: Ramjet forum
Topic: Subsonic Ramjet Design Project
Replies: 15
Views: 3675

Subsonic Ramjet Design Project

Hi! For the past few months, I've been developing a low-speed ramjet engine design. The design itself is mostly original- it isn't by any means a typical "coffee mug" style engine, as you can see in the image below. RJ2-Views.png Now, before you tell me I've got scramjets on the brain, let me explai...