Fuel pump

[richardm]

Or maybe multiple nozzles..primary and a secondary kicking in at some preset pressure... Or a duplex nozzle.... stuff to cogitate on

Still pretty amazing how inefficient a turbo based engine can be compared to a real turbine engine

Those PT-6 engines ( Nozzle is from one) yields 620 shaft hp on top of the energy required to drive its compressor and accessories plus a little residual thrust on about 450 pounds an hour at max power

I will eventually be burning some 75 pounds and might not get 110 pounds of thrust...

But we know it and keep going Just for the fun of it.

Hope no climate anxious guy is reading ...

[racket]

If you compare our turbo based engines to the early jet engines like the Ghost with their radial comps , we're not too bad actually , similar pressure ratios and comp efficiencies whilst we can probably run a tad higher temps , at a lower efficiency , we can get ~60 lbs of thrust per pound per second , the Ghost produced 5,000 lbs from 88 lbs/sec or ~57 lbs/lb .

The Goblin produced ~3,000 lbs at a SFC of ~1.23 lbs /lb . whilst your 110 lbs for 75 works out at only 1.46 SFC , less than 20% extra , not bad considering the scale issues .

Our DIY turbo based engines do a pretty good job considering they're not designed for producing thrust :-)

[richardm]

I wrote about adding nozzles yesterday... Can't say were goes my brain when Im asleep but I woke up remembering those old British jets like the " Viper " series. I think they used vaporizer tubes but with some kind of a starting fuel nozzle to heat em up. Do you know anything about that ? I could maybe use that idea since I already have a nozzle based system. Just had a vaporizer of some sort and pump some more fuel in it after its started up. What do you think?
You' say that a bigger fuel nozzle is the easiest mod but where do you get a nozzle capable of that much flow...

[racket]

Hi Richard

Have a look at my kart build jetandturbineowners.proboards.com/thread/40/2-shaft-turbine-kart-build for vapouriser setup .

Plenty of oilburner spray nozzles in bigger flows , I used them in my bike build , ~6GPH at 750 psi delivery pressure , you probably only need a 6 GPH ( rated at 100 psi ) nozzle if running 250 psi

Cheers
John

[richardm]

Ok Thanks I Thought I would have to look for something like 10 or 12 GPH as i m now pumping 3.2 gph ( US) at 250 psi

[racket]

Hi Richard

Sq root 250 = 15.8 , sq root 100 (rating pressure) =10 , 15.8/10 = 1.58 more flow , your current 3.2/1.58 = 2.02 GPH nozzle at the usual rated 100 psi , so 3 times gives us a 6GPH nozzle which will eventually flow ~9.5 GPH (6 X 1.58 ) at 250 psi

My bikes 6GPH nozzle at 750, sq root 27.3 , div 10 = 2.73 , 6 X 2.73 = 16.43 GPH flow .

My 88 mm inducer = 6082 sq mms , your 71 mm 3959 , mine was 1.53 times larger area , 16.43 gph/9.5gph = 1.72 times , LOL......I was running it kinda hot and hard :-)

Hope this helps .

Cheers
John

[richardm]

Thanks again! You're THE man!

[richardm]

Here are some picture of my fuel and oil module  I designed it as a module so that it can be used on another build later.  It supplies  fuel at 250 psi @ up to 30 liters / hour
Oil pressure is regulated at 50 psi and is cooled by a small radiator and 2 fans @ 360 cfm. They can be manually turned on or auto by a thermostatic switch. Also has an oil pressure sensor  an adjustable oil pressure switch and an  oil temp sensor.

[racket]

Hi Richard

Thats one fine looking collection of bits and pieces made into a very handy module :-)

Beautiful workmanship , neat and tidy , a lot of thought gone into its construction , I admire the finer details , nice .

Cheers
John

[richardm]

Thanks ! That's my way of having fun.. Im about to install it on the cart just underneath the engine and I'll do the connections and some testing, looking for leaks . I will also adjust the oil pressure regulator to fit the turbo requirements. So far oil pressure tests have been conducted using a ball valve as a restriction. Im planning to set ii at 50 psi . That test will be made with oil at room temp but the regulator should be able to compensate as the oil warms up . Also , being curious ,I want to measure the oil flow trough the turbo for future reference .

I also want to measure total watts to drive the oil and fuel pump / regulator . This could be translated in HP. Could be useful on a future build that would be self sufficient ( no external power to drive those)

I'll post those numbers but for now the weather Gods are nice and I have a lot to do around the house. Waiting for rainy days Can't believe I just wrote that....LOL