www.pulse-jets.com

Turbos don't have a problem with "intermittent" flow to an IC engine unless the engine has less than 4 cylinders , if on a 2 cylinder engine then a large volume plenum is recommended to dampen out pulses ,I think I used a plenum of ~1.5 times engine capacity , the turbo rpm do change slightly as ...

Hi Luc

LOL..............a simply little job

I'll think on it .

Cheers
John

Hi Luc

Let me get this straight ....................you want to feed the output from the GT2560 into another GT2560 , this is even less likely to work , any freepower turbine will need to have a flow capacity twice the gas producers due to the lower gas densities and velocities achievable from the ...

Hi Luc

Your GT4708R units aren't "working hard" , they're running rather cold so the relatively small turbine stage isn't a problem , once you get a turbine "working" with T I Ts of 900 C and above, the lowered density of the gases soon cause problems with undersized flow areas , we soon go into ...

Hi Luc

The GT2560R turbos won't work :-(

With a 46.5mm comp inducer -1698 sq mms , we'd normally require a turbine exducer area at ~25% bigger , or 2122 sq mms or 52mm diameter , the GT2560R has a very small turbine wheel of 53mm inducer but with a 62Trim it only has an exducer diameter of ~41 ...

Hi Luc

Nice graphics

Been in hospital for a couple of weeks so haven't been able to keep up to date on what you're up to .

Cheers
John

Hi Luc

The smaller first stage gap could be better due to the finer entrainment at that point not requiring a lot of air , downstream as the jet surface starts to get "rougher" the larger clearance will have the capacity to supply air into that rougher jet boundary layer .

Have you looked at ...

Hi Luc

LOL.....you're such a flatterer :-) ................heh heh , you should know I don't have an ego , flattery is wasted on me .

Yep , making sense why you need those 2 ejectors now .

Laminar flow downstream of the nozzle will keep backpressures to a minimum , is there any way you can add ...

Hi Luc

Checkout the length of jet nozzle I used on my GT6041 http://jetandturbineowners.proboards.com/thread/78/garrett-gt6041-powered-kart?page=8 , I used a central " boss" tube and straightening vanes to produce a smooth laminar flow into the jet nozzle , the gases exiting a turbo exducer fed ...

Hi Luc

From doing a few numbers your 2.9" nozzle should have been putting out ~40 lbs of thrust at 80,000 rpm even with those low temps , that very efficient comp wheel works a treat

Yeh , industrial units need a big safety component , you got it pretty well spot on .

Cheers
John

Hi Luc

What sort of P2 pressures were you running the GT4708 up to ??

Heh heh , ........800 C exhaust would have been "interesting" in that industrial use .

Cheers
John

Hi Luc

LOL.....Theres no need for Jetspecs anymore , lotsa Youtube videos showing how to make a jet engine from a turbocharger using "stolen" info from the DIY Site .....................heh heh , its a pity most of them won't work properly though because the guys making the videos don't understand ...

Hi Luc

If only it was so easy to give simple answers to the Rules of Thumb question . ..........................there are just so many variable to consider,........... big turbo with narrow map high pressure capability vs small turbo with wide map but limited pressure , diesel vs petrol turbo ...

Hi Luc

LOL.........I helped design Jetspecs , Jesse took my Rule of Thumb numbers from the Yahoo DIY Gas Turbines Site and put them into a workable Program , we spent months getting it "sorta right" , its not perfect but it does produce a working engine , so I'd still recommend a large combustor ...

Hi Luc

The ABB turbos are very expensive :-(

Yeh , Springer should be sued for false advertising , it really is all crap , just another poorly attempted money grab from unsuspecting guys wanting to build a turbine engine , thats why the DIY Gas Turbines Site was able to help out .

Our thrust ...