Wow, I have been really swamped since the beginning of the year. My goals of getting the ATR history and performance posts out are yet to be fulfilled.
But hang with me, and I'll make it worth your wait.
In the meantime, check out some of my archived posts, they are definitely worth reading, IMHO.
But I don't think you have dusted the archives lately and I have allergies.
Posted by: john hare | March 05, 2010 at 03:44 PM
John H,
I'm sorry, but I just don't get your allegory....
Posted by: John Bossard | March 05, 2010 at 06:13 PM
Apologies. The mental picture that springs to my mind with the word archives is a huge old room full of scrolls and books so old that the pages are brittle and everything so dusty that you leave footprints on the floor. Probably comes from watching too many bad movies.
Posted by: john hare | March 06, 2010 at 01:13 PM
John B:
I know your busy and all but I found an interesting presentation on an H2O2/JP-5 rocket motor that someone saved from being salvaged.
It is a Reaction Motors Inc. LR-40 "super-performance" rocket designed and built in the late '50s for jet-aircraft assist.
Site:
http://www.gkllc.com/history/rmi/AIAA-2001-3838_History_of_RMI_Super_Performance_90_Percent_H2O2-Kerosene_LR-40_RE-pitch.pdf
Pertinent points and question:
-2 LR-40s were built and one test fired during demonstration, continuous throttlin, both monopropellant and duel propellent modes tested total fireing time: 5400 seconds (90 minutes/ 1.5 hours)
- Turbopump is a single shaft design powered by decomposed H2O2 prior to entry into oxidizer/monopropellant feed turbopump and exhausted through engine. In-line design with all major assemblies alinged for an outside diameter of only 14 inches.
-Turbopump shaft speed is constant at 18,800 RPM
Question: How much TP power loss would there be for hooking a compressor fan to the turbopump shaft? What size of ATR duct would be needed? 24"? Larger?
Is this viable as a core for an ATR type engine?
Randy
Posted by: Randy Campbell | March 25, 2010 at 08:54 AM
Randy C.,
sorry for the delay in responding.
As it turns out, the turbine end of rocket-type turbopumps can make a pretty good starting point for ATR turbines.
FWIW, pumps have higher thermodynamic efficiency than compressors (easier to rise the pressure of an "incompressible" fluid). So one could expect the TP power loss to be greater for a compressor than for a pump. Hard to give any numbers without doing some calcs.
The duct size would be determined the OD of the compressor disk. You can can a rough idea of compressor dia by assuming a tip speed of around 800-1000 ft/sec, and using your rpm
Could well be a viable core for an ATR type engine. This is in fact the very reason that I purchased an LR-504 turbopump turbine and manifold from Norton Salvage about 10 years ago. An engine this size would likely be in the 1500-2500 lbf static thrust class.
Hope this is helpful.
Posted by: John Bossard | April 12, 2010 at 01:43 PM
Thanks for the reply John and yes it does actually help :)
I was particularly interested in this motor design as it was so compact. Being a "stacked" motor with the fuel/oxidizer turbopumps placed in-line (on-top) of the rest of the motor.
As usual I can't seem to get any responses from the company itself to my questions, (then again given the nature of some of my questions they may just have put me on a spam-filter :) ) I can only go so far with speculation. It's nice to have an "expert" to bounce such stuff off of.
Again, thanks
Randy
Posted by: Randy Campbell | May 07, 2010 at 01:17 PM