Search found 539 matches

by skyfrog
Fri Jul 28, 2006 11:57 am
Forum: Gas turbine forum
Topic: Johansson´s Pocketbike
Replies: 431
Views: 245572

re: Johansson´s Pocketbike

Nice work, Anders.

One quick question, don't you need a screen on the front of the intake to prevent FOD ? The intake is so low, just above the ground maybe 15 cm, and is so close to the back of the front wheel, be careful of the FOD, dirt, pebbles etc.
by skyfrog
Sat Jul 15, 2006 1:58 pm
Forum: Gas turbine forum
Topic: Gas (Tesla) Turbine started
Replies: 80
Views: 67515

re: Gas (Tesla) Turbine started

Good job Nick, it looks beautiful.

Have no idea of how tesla turbine works though.
by skyfrog
Sat Jul 15, 2006 5:32 am
Forum: Rocket forum
Topic: Different values on gamma and k?
Replies: 12
Views: 7618

re: Different values on gamma and k?

For ideal gas, gamma is constant, so is k, but you are dealing with real gas. In general, for real gases over normal working ranges of pressure and temperature, gamma (and Cp, Cv etc) is a function of temperature alone. Furthermore, if dissociation is taken into account, in which case when temperatu...
by skyfrog
Mon Jul 03, 2006 2:10 pm
Forum: Rocket forum
Topic: Different values on gamma and k?
Replies: 12
Views: 7618

re: Different values on gamma and k?

I left this question to be answered by yourself, the trick is to find a correct thermodynamics textbook which involves combustion.

Not meant to be offensive but howcome I got this feeling that you're a student ?
by skyfrog
Sat Jul 01, 2006 5:40 am
Forum: Off topic forum
Topic: Yin and Yang of Putt and Putt
Replies: 3
Views: 3005

Re: re: Yin and Yang of Putt and Putt

Cost per item: US $2.63 each (Not sold individually) huh? India will beat China in war of price competiton if this trend goes on for some years. As Confusion says, I don't understand! OT: Yeah Confucious made me kind of confusion too. hehe. Confucious ran a cram school thousands of years ago. The f...
by skyfrog
Sun Jun 18, 2006 1:12 pm
Forum: Gas turbine forum
Topic: freepower turbine?
Replies: 3
Views: 4066

Re: freepower turbine?

I found the following page very useful in learning the concept of a power turbine: http://www.rcdon.com/html/gr-5_turboshaft_engine_project4.html I wouldn't try rcdon's turbine as it is welded rather than cast. No matter how many welding certificates you've got, welding is simple a wrong method of ...
by skyfrog
Sat Jun 17, 2006 1:18 pm
Forum: Gas turbine forum
Topic: freepower turbine?
Replies: 3
Views: 4066

re: freepower turbine?

Well, please allow me I see other forum members are busy couldn't answer your question. Free power turbine is a power turbine that is mechanically independent with other turbines. ie, free power turbine does not coupled with any other turbines via shaft. Please note the difference between thermodyna...
by skyfrog
Sat Jun 17, 2006 12:59 pm
Forum: Gas turbine forum
Topic: do compressor wheels "explode"?
Replies: 23
Views: 13337

re: do compressor wheels "explode"?

Hi, Radial flow turbines or compressors are very strong in comparison with that of its axial flow counterparts, because the former have longer blade root while the later have short one. Mathematically speaking, consider the blade as a plate placed in a X-Y coordinate, we see that radial flow blades ...
by skyfrog
Fri Jun 16, 2006 5:58 am
Forum: Off topic forum
Topic: Conception GLC is hiring
Replies: 8
Views: 3152

re: Conception GLC is hiring

Hi Viv,

Congratulations for Conception GLC a fast growing company. Best wishes,
by skyfrog
Sun Jun 04, 2006 4:59 pm
Forum: Gas turbine forum
Topic: A small gas turbine with Axial Flow Compressor!
Replies: 73
Views: 66823

Re: re: A small gas turbine with Axial Flow Compressor!

I hope after John and other member's helps, Arman could finally understood that for the time being his action shouldn't be in the machineshop making parts but rather get to the library first and study hard. I remember having problems with overheating, I was running around 1100 instead of 800-1000, t...
by skyfrog
Fri May 26, 2006 3:08 pm
Forum: Gas turbine forum
Topic: 160,000rpm
Replies: 25
Views: 17556

re: 160,000rpm

Hi Arman, My turbine is made from inconel 713, a nickel based heat-resistant super alloy. We had tested them up to 170K rpm flawlessly. It was vacuum melt and vacuum cast, fully X rayed. Yes I just saw your thread, congrats your nice piece of work, the axial compressor looks great, I'd like to ask t...
by skyfrog
Sat May 06, 2006 2:18 am
Forum: Gas turbine forum
Topic: 160,000rpm
Replies: 25
Views: 17556

re: 160,000rpm

Hi Anders, Sorry for getting you guys waiting this long, I promise you guys X150 has shinny future. There's not a bank standing behind us supporting the project, it was insufficient funds that made us stop the development of X150 and turned to OEM business. In other words, I have to make parts for o...
by skyfrog
Fri May 05, 2006 1:53 pm
Forum: Off topic forum
Topic: A Fresh Slice Of Pi
Replies: 3
Views: 2362

re: A Fresh Slice Of Pi

Congratulations Larry ! A proud father I can imagine. I hope my little girl could be this good in math too. BTW, she's only 5, but I see no clues of any math talents she'll develop.
by skyfrog
Fri May 05, 2006 1:00 pm
Forum: Gas turbine forum
Topic: 160,000rpm
Replies: 25
Views: 17556

re: 160,000rpm

I guess so, if their OD is similar to ours. But remember, turbochargers use radial flow turbine wheels which are machanically more robust than axial flow ones, and besides, the turbine inlet temperature is not so high as what was experienced in turbojet engines. I am surpirsed this thread come up ag...
by skyfrog
Thu May 04, 2006 12:04 pm
Forum: Gas turbine forum
Topic: How does a turbine jet engine work
Replies: 4
Views: 4266

re: How does a turbine jet engine work

Well said Ben, I totally agree your points.