Jetbeetle X-150 nearing completion!

Moderator: Mike Everman

Post Reply
Johansson
Posts: 1161
Joined: Sun Nov 21, 2004 9:42 pm
Antipspambot question: 0
Location: Northern Sweden

Jetbeetle X-150 nearing completion!

Post by Johansson » Sun Jan 14, 2007 2:01 pm

Old habit made me surf by Skyfrog´s homepage to see if anything has happened on the X-150, it was a while since he updated the homepage so I was beginning to think that he gave up the project.

I was very wrong, he has updated the homepage on several fronts lately and the first test run is soon unveiling! Fun fun fun!

http://jetbeetle.com/

//Anders

Zippiot
Posts: 1190
Joined: Tue Nov 15, 2005 7:55 pm
Antipspambot question: 0
Location: california
Contact:

Post by Zippiot » Sun Jan 14, 2007 7:01 pm

AWSOME!!

It looks great, how long has it been in the works?
Sailing Student- How do I know if my life jacket is tight enough?
Me- Can you breathe?
Sailing Student- Yes
Me- Then its too loose!

Zippiot
Posts: 1190
Joined: Tue Nov 15, 2005 7:55 pm
Antipspambot question: 0
Location: california
Contact:

Post by Zippiot » Sun Jan 14, 2007 7:01 pm

nevermind the dates are on the site :)
Sailing Student- How do I know if my life jacket is tight enough?
Me- Can you breathe?
Sailing Student- Yes
Me- Then its too loose!

skyfrog
Posts: 539
Joined: Fri Jul 23, 2004 11:39 am
Antipspambot question: 0
Location: Kaohsiung, Taiwan
Contact:

test run

Post by skyfrog » Tue Jan 16, 2007 5:13 am

Thank you Anders and Zippiot for your warm support.

During the past period of x150 project, I received many supportive emails from all over the world, they were and still will be in the future, the true driving force of this self-suficient project.

We made oem parts for survival during the past, this month I am still occupied by works of orders filling. I think for two more weeks I can start testing the engine.

The new PR5 (pressure ratio 5.0) compressor is very promising, it will bring x150 to a new stage, I believe. So don't go away, I will show you something interesting !
Long live jet engine !
Horace
Jetbeetle

racketmotorman
Posts: 503
Joined: Sat Jul 23, 2005 11:11 pm
Antipspambot question: 0
Location: Australia

Post by racketmotorman » Thu Jan 18, 2007 4:21 am

Hi Horace
I'm looking forward to hearing of your first test runs .
I also pop into your site from time to time to check progress, love to look at your beautiful workmanship :-))........ah , to have your machine tools to play with .
Cheers
John

skyfrog
Posts: 539
Joined: Fri Jul 23, 2004 11:39 am
Antipspambot question: 0
Location: Kaohsiung, Taiwan
Contact:

critical rotational speed (CRS) program

Post by skyfrog » Fri Jan 19, 2007 4:08 pm

Hi John, thanks for your support too.

I have developed a finite element method based program called CRS (critical rotational speed), for analysing the natural frequencies of micro gas turbine's shaft. I am comparing the program output using benchmarks such as P66 in Kamps' book, and it shows consistency. (in fact ours is more accurate than than kamps', because ours is their lower bound)

I will upload the version 1.0 to our website for free download. The only problem of this program is the user interface, it is written in fortran, not C++, so right now only command line is available. I hope to add window dialog interface if I have time to do it.
Long live jet engine !
Horace
Jetbeetle

skyfrog
Posts: 539
Joined: Fri Jul 23, 2004 11:39 am
Antipspambot question: 0
Location: Kaohsiung, Taiwan
Contact:

Analysing critical rotational speed of shafts

Post by skyfrog » Sun Jan 21, 2007 12:13 pm

Case 1. Kamps shaft (illustrated in book Model jet engines 2nd edition, page 66)

D1 = 0.007 (m), diamter of shaft segment 1
D2 = 0.014 (m), diamter of shaft segment 2
D3 = 0.007 (m), diamter of shaft segment 3
L1 = 0.016 (m), length of shaft segment 1 (bearing to c.g. of compressor)
L2 = 0.096 (m), length of shaft segment 2 (bearing to bearing)
L3 = 0.012 (m), length of shaft segment 3 (bearing to c.g. of turbine wheel)
RHO = 7.85 (T/m**3), density of steel
E = 2.070D8 (kN/m**2), young's modulus of steel
Mc = 6.2D-5 (T), lump mass at c.g. of compressor
Mt = 7.0D-5 (T), lump mass at c.g. of turbine wheel

Critical rotational speed :
a. Kamps' book = 136,270 rpm
b. CRS result = 125,200 rpm

Design speed :
105,000rpm

Check our website for details. Kamps' book based on formulae stated by Bohl. Ours based on finite element method.
Attachments
CRS02.JPG
CRS02.JPG (6.34 KiB) Viewed 8146 times
Last edited by skyfrog on Sun Jan 21, 2007 1:10 pm, edited 1 time in total.
Long live jet engine !
Horace
Jetbeetle

Fricke
Posts: 325
Joined: Tue Mar 01, 2005 8:17 pm
Antipspambot question: 125
Location: Southern Sweden
Contact:

Re: Analysing critical rotational speed of shafts

Post by Fricke » Sun Jan 21, 2007 1:00 pm

skyfrog wrote:Critical rotational speed :
a. Kamps' book = 136,270 rpm
b. CRS result = 12,520 rpm

Design speed :
10,500rpm
Hi Horace!

Is the results correct?

You have 136k RPM for a, 12,5k RPM for b and 10,5k RPM for c!
"woot"
A shrill, obnoxious noise/word used by immature people to express happiness or excitement.
Supposedly started in the gamer community, but is now used by any slack-jawed moron to express delight.

skyfrog
Posts: 539
Joined: Fri Jul 23, 2004 11:39 am
Antipspambot question: 0
Location: Kaohsiung, Taiwan
Contact:

Re: Analysing critical rotational speed of shafts

Post by skyfrog » Sun Jan 21, 2007 1:11 pm

Fricke wrote: Hi Horace!

Is the results correct?

You have 136k RPM for a, 12,5k RPM for b and 10,5k RPM for c!
Oops, typo I've corrected, sorry for that.
Long live jet engine !
Horace
Jetbeetle

skyfrog
Posts: 539
Joined: Fri Jul 23, 2004 11:39 am
Antipspambot question: 0
Location: Kaohsiung, Taiwan
Contact:

KJ66 shaft analyzed

Post by skyfrog » Tue Jan 23, 2007 12:28 pm

I got critical rotational speed for KJ66 shaft. My program shows 127k rpm and the max rpm set was 117k rpm, quite reasonable right ?
Attachments
CRS_KJ66.JPG
critical rpm for kj66 shaft
CRS_KJ66.JPG (45.24 KiB) Viewed 8052 times
Long live jet engine !
Horace
Jetbeetle

skyfrog
Posts: 539
Joined: Fri Jul 23, 2004 11:39 am
Antipspambot question: 0
Location: Kaohsiung, Taiwan
Contact:

CRS program - new user interface is done.

Post by skyfrog » Thu Mar 08, 2007 9:11 am

Hi All,

The new user interface for our CRS program is done !
1. It is based on Windows so is very user friendly.
2. It has a convenient file i/o utility so you could store the analysis cases for later run. Some sample input files are included in the installation file (zip file actually :-) unzip and the installation is done).
3. Help button is added just hit the button for instructions of how to use.
4. It is ideal for shaft designers, because now user can fine-tune the input data by trial and error and obtain the critical rpms in a second.
5. Currently only one type of shaft is available in the program, more to come in the subsequent versions !

Any feedbacks are welcomed !
Attachments
CRS_Ui.JPG
New user interface for CRS program
CRS_Ui.JPG (36.81 KiB) Viewed 7602 times
Long live jet engine !
Horace
Jetbeetle

Post Reply