Heresy

[paul skinner]

What up, Principal? I posted some time ago the idea of superheating liquid fuel with engine heat, but keeping it liquid in the coil between a high pressure injector and a gear pump, or maybe the engine vibration can be harnessed somehow for high pressure pumping. Point is, keep it liquid with pressure between pump and injector so the injected fuel is atomized as well as vaporized upon entering the chamber.
Sounds also like dangerous experiments...

Mostly lurking these days, as I'm in the process of finishing my little Cri Cri in anticipation of getting it into the air finally (7 years in the making)..

(Damn JPX engines)..

:)

[luc]

Heyyy ... Viv,

He he he .... Amazing how I can get your attention real quick ... Just a little comment ... Or bitching arround ... And there you are ... He he he.

Keep it up Bud ... After all, we do a Damn good job.

Bye the way ... One day, you will have to show me that Logan / Chinees engine. I hear you talk about it all the time and I have never saw one.

Cya guys ............. Qaplaaaaaa

Luc ......... Out

[hinote]

Mostly lurking these days, as I'm in the process of finishing my little Cri Cri in anticipation of getting it into the air finally (7 years in the making)..

(Damn JPX engines)..

:)

Have you considered (pulse-) jet power for your Cri Cri? It's already been done (turbojets). You wouldn't need a whole lot of thrust to get into the air.

I'm hoping to get started on my airframe this year, to demonstrate pulsejet power on manned aircraft. It's a modern version of the He-162 Salamander in concept, with the power pack piggybacked over the fuselage. It will be all composite (mostly carbon), and with 200 lbf thrust powering a gross weight of 790 lb it should have considerable performance.

If you start subtracting weights for pilot, fuel and engine you get a raw airframe weight of about 250 lb. This should be easily "do-able" in composite (also in aluminum--but I'm a composite guy).

It's a big project, but I think it's a challenge worth pursuing.

Bill H.
Acoustic Propulsion Concepts

[Viv]

Mostly lurking these days, as I'm in the process of finishing my little Cri Cri in anticipation of getting it into the air finally (7 years in the making)..

(Damn JPX engines)..

:)

Have you considered (pulse-) jet power for your Cri Cri? It's already been done (turbojets). You wouldn't need a whole lot of thrust to get into the air.

I'm hoping to get started on my airframe this year, to demonstrate pulsejet power on manned aircraft. It's a modern version of the He-162 Salamander in concept, with the power pack piggybacked over the fuselage. It will be all composite (mostly carbon), and with 200 lbf thrust powering a gross weight of 790 lb it should have considerable performance.

If you start subtracting weights for pilot, fuel and engine you get a raw airframe weight of about 250 lb. This should be easily "do-able" in composite (also in aluminum--but I'm a composite guy).

It's a big project, but I think it's a challenge worth pursuing.

Bill H.
Acoustic Propulsion Concepts

Hell i think we all would like a peace of that Bill:-)

If you need help then ask for it!

Viv

[Bruno Ogorelec]

Have you considered (pulse-) jet power for your Cri Cri?

I don't think the placement of engines on the Cri-Cri is very good for pulsejet power. Whoever uses big pulsejets should mount them well aft so that the acoustic blasts do not tear at the airframe. Look at all the WW II German efforts and you'll see how far aft most of them put their engines. It was for a very good reason.

[paul skinner]

Have you considered (pulse-) jet power for your Cri Cri?

I don't think the placement of engines on the Cri-Cri is very good for pulsejet power. Whoever uses big pulsejets should mount them well aft so that the acoustic blasts do not tear at the airframe. Look at all the WW II German efforts and you'll see how far aft most of them put their engines. It was for a very good reason.

Exactly. The engines are mounted on twin outboard nacelles, that are specifically designed to hold either JPX, Rotax, or Limbach type motors. I toyed with the idea early on of using a pair of twin Phoenix 30.3 (mk4 upgrade) or perhaps a pair of KJ-66 (microturbines), but quickly threw out the idea after analyzing fuel consumption. It also contravened several Transport Canada Safety rules, not the least of which is a rating in multi-engine instrument and turbo-jet engine (which I am not qualified for). Presently the rules regarding the cri cri allow me to fly with my present rating (private, vfr-ott, and night). I plan on getting my multi-engine next fall.
I built an Affordaplane back in '00 (google for info if you're interested) and tried putting a small pulsejet on the inboard strut. I flew with it experimentally twice (at less than 5 meters with a top air speed of 45kmh) and yes. It worked. But it's not something I would do again, and something that could have easily lost me my license (since I am not qualified or rated test pilot obviously).

:)

[Viv]

Look at you guys..... You so funny to watch...

Well, it's better than sex in some respects. You can do it even when your weenie wilts. But, in defense of the many participants here, these people do not just argue. Many engines get built, too. I have lost couint of how many engines have been built and tested by forum participants over the past four years.

What I'm interested in is comparateive figures. SFC, for instance. Does continuous nonsteady combustion of this sort beat intermittent combustion of a pulsejet? I'm also very strongly interested in the high pressure heater/injection fuel system. To me it looks perfect, but Bill Hinote (a man of considerable practical experience) says such systems are terribly prone to coking up.

Well I am just going to repost this answer/question from Bruno to pull the thread back on to track.

Now if you read what he has said you will find that he has asked the important questions and that he has boiled the problem down too the basics.

Viv

[luc]

Okey...Good morning guys,

Not to had up to your airfram technical debate, but I could not resiste say this.

Principal Shinner ... Look to me like you have a damn good project. But when I heard about the plane type / PulseJet combination, the first thing that came to my mind was "With twin pulsejets mounted well apart from the center line ... You better make sure your tail rudder trim capablilities are enhanced. Remember that pulsejets are not very throttleable and if you loose one before the other, you will find your self in a situation with ALOT of assimetric thrust. You won't be able to slow down that engine, or it will quit, therefore, you could have one engine dead and one engine giving Max. thrust.

Assimetric thrust and flat spin ... Kills Pilots... Remember the Paris Airshow Mig-29 crash ... Perfect exemple.

As for the debate.... I have given my opinion on that ...

Cya,

Luc..........................Out

[hinote]

I'm also very strongly interested in the high pressure heater/injection fuel system. To me it looks perfect, but Bill Hinote (a man of considerable practical experience) says such systems are terribly prone to coking up.

Viv, I would HATE to be recorded as a person who discouraged development of a good vaporizing system.

I'm just not inclined to complicate my (pulsejet) life further with the potential aggravations involved.

It MAY be possible to successfuly develop a usable vaporizing system, but refinements such as high fuel velocity, and system drainage/purging MAY need to be included to make it successful.

Bill H.
Acoustic Propulsion Concepts