Search found 503 matches

by racketmotorman
Thu Jul 08, 2010 9:59 pm
Forum: Gas turbine forum
Topic: Turbo jet?
Replies: 2
Views: 2688

Re: Turbo jet?

Hi Jacob

With such a small turbo you'll undoubtedly be using propane/LPG as a fuel , in which case a smaller flametube is possible due to the fast burn characteristics of the gaseous fuel , possibly down to 3-3.5" dia and 6 inches long.

Cheers
John
by racketmotorman
Sun May 02, 2010 3:14 am
Forum: Gas turbine forum
Topic: A few questions about a/f ratios and injection/ignition
Replies: 29
Views: 13026

Re: A few questions about a/f ratios and injection/ignition

Hi

Its just another unworkable system :( ...................theres "millions" of them out there in the Patents Office .

My last posting on this subject , all the best with your project :D

Cheers
John
by racketmotorman
Sat May 01, 2010 9:33 pm
Forum: Gas turbine forum
Topic: A few questions about a/f ratios and injection/ignition
Replies: 29
Views: 13026

Re: A few questions about a/f ratios and injection/ignition

Hi LOL......Its not going to be too hard to shoot holes :D ....................the concept is flawed because of basic thermodynamics and energy transfer inefficiencies . Have you considered the need for a variable pitch prop in your system ??? .....................you'll need one, otherwise your sta...
by racketmotorman
Thu Apr 29, 2010 6:01 am
Forum: Gas turbine forum
Topic: A few questions about a/f ratios and injection/ignition
Replies: 29
Views: 13026

Re: A few questions about a/f ratios and injection/ignition

Hi Heres some concrete numbers that'll help . The Garrett TV84 turbo I used for my bike build http://www.racketmotorman.turbinebuilder.com/thumbnails.php?album=3 produced a 4:1 PR at excessive rpm , by running at excessive temperatures ( TITs) it produced 110 lbs of thrust from a mass flow of 1.8 lb...
by racketmotorman
Thu Apr 29, 2010 5:19 am
Forum: Gas turbine forum
Topic: A few questions about a/f ratios and injection/ignition
Replies: 29
Views: 13026

Re: A few questions about a/f ratios and injection/ignition

Hi

OK , no turbine wheel to extract power to spin the comp .........................it won't work !!

Cheers
John
by racketmotorman
Thu Apr 29, 2010 3:42 am
Forum: Gas turbine forum
Topic: A few questions about a/f ratios and injection/ignition
Replies: 29
Views: 13026

Re: A few questions about a/f ratios and injection/ignition

Hi I started reading the report and theres too much difference between what you propose and this study to make it applicable . Firstly they used cold air , .................where is your working fluid coming from ?? How is your working fluid compressed ?? Where is the horsepower for compression comi...
by racketmotorman
Thu Apr 29, 2010 12:03 am
Forum: Gas turbine forum
Topic: A few questions about a/f ratios and injection/ignition
Replies: 29
Views: 13026

Re: A few questions about a/f ratios and injection/ignition

Hi Fuel efficiency is a product of the expansion ratio , we need a PR of at least 6:1 for it to become acceptable , you won't get that with a turbo , once past a PR of ~4:1 the comp efficiencies drop beyond the point where any further pressure rise doesn't produce any significant benefits even thoug...
by racketmotorman
Wed Apr 28, 2010 9:47 pm
Forum: Gas turbine forum
Topic: Picked up a pair of Schwitzer S500:s today.
Replies: 29
Views: 13460

Re: Picked up a pair of Schwitzer S500:s today.

Hi Anders

Thats been burning nicely :-))

Cheers
John
by racketmotorman
Wed Apr 28, 2010 9:44 pm
Forum: Gas turbine forum
Topic: A few questions about a/f ratios and injection/ignition
Replies: 29
Views: 13026

Re: A few questions about a/f ratios and injection/ignition

Hi Don't worry about fuel , turbines will burn just about anything if designed correctly . Get the books and read them several times , they may be for models but they relate to much larger units as the maths don't change all that much , gas turbines scale up rather well . Once you've read the books ...
by racketmotorman
Wed Apr 28, 2010 6:12 am
Forum: Gas turbine forum
Topic: A few questions about a/f ratios and injection/ignition
Replies: 29
Views: 13026

Re: A few questions about a/f ratios and injection/ignition

Hi I'm still uncertain how this "contraption" is supposed to work , what is powering the compressor ?? There are a number of "problems" I foresee with the setup..................may I suggest you purchase a couple of small and relatively inexpensive books to give yourself some grounding in the funda...
by racketmotorman
Wed Apr 28, 2010 2:23 am
Forum: Gas turbine forum
Topic: A few questions about a/f ratios and injection/ignition
Replies: 29
Views: 13026

Re: A few questions about a/f ratios and injection/ignition

Hi LOL.......Turbonetics do a lot of "turd polishing" , they'll talk up anything . If you checkout centrif comps for aero engines , eg the RR 250 heli engines , their titanium comps ( and we need Ti comps due to the high temps of compression degrading alloy comps once past a PR of ~5-6 :1 ) only run...
by racketmotorman
Tue Apr 27, 2010 10:12 pm
Forum: Gas turbine forum
Topic: A few questions about a/f ratios and injection/ignition
Replies: 29
Views: 13026

Re: A few questions about a/f ratios and injection/ignition

Hi Unclematt All of these methods have been tried and found wanting over the years , thats why we see the type of turbine engines we do . Spark plugs are for initial ignition only and can be deactivated once the fire alight . Fuel injection can either be high pressure ( ~500 psi) or low pressure wit...
by racketmotorman
Mon Apr 19, 2010 3:40 am
Forum: Gas turbine forum
Topic: turbine
Replies: 10
Views: 5224

Re: turbine

Hi MTC What you are playing with is a freepower turbine , its free to rotate independently of the gas producer rotor , the Allison 250 helicopter engine has 2 freepower turbines producing the ~400 shaft horsepower , the larger is 212mm -8.5" in dia and both rotate at 33,000 . To have a "slowly" rota...
by racketmotorman
Mon Apr 19, 2010 2:24 am
Forum: Gas turbine forum
Topic: turbine
Replies: 10
Views: 5224

Re: turbine

Hi MTC Yep , I understand confidential information :-) All gas turbine freepower turbine wheels can create maximum torque at nil rpm , generally ~ twice max rpm torque , the maximum total pressure that my bikes freepower turbine experiences is ~12psit , this is a mix of several psi of static pressur...
by racketmotorman
Mon Apr 19, 2010 12:03 am
Forum: Gas turbine forum
Topic: turbine
Replies: 10
Views: 5224

Re: turbine

Hi MTC Without knowing more about your particular turbine its impossible to give any indications as to how/if afterburning/interburning would be effective or possible. Turbines need to be run at fairly high speeds to efficiently convert dynamic gas energy into shaft energy , my bike engine http://ww...