The DP-2 concept, and the DP-1 test aircraft, incorporated extensive use of composites. The airframe structure was manufactured out of two types of composite material systems, one for the basic airframe and the other for the TVCS area that requires exposure to high temperatures. The airframe structure was mostly manufactured using a fiberglass reinforced polyimide honeycomb (HRH-327) and graphite and cyanate ester prepreg skin (LTM45) configuration. All of the structure was vacuum bag/oven cured instead of using an autoclave. Major joints of the airframe were bonded together using film adhesive, minimizing fastener use. The material choices would be a concern if the concept were to be operated in a maritime environment, but were usable in the test article to prove the concept.
The major risk with composite materials was in the exhaust hot section. The nozzle box in which the TVCS was mounted, the cascades, the deflection doors, and the control surfaces were manufactured from composite material. Several delaminations and failures of nozzle box honeycomb sandwich panels were experienced during the course of testing. Eventually all honeycomb sandwich panels in the nozzle box, cascades, and doors were replaced with a coreless construction, using skins supported by an internal truss structure. Material used was graphite and cyanate ester prepreg matrix material (Advanced Ceramics Group LTM110).
http://gop.science.house.gov/Media/Hearings/oversight07/June12/scheuren.pdfThe team (in 1996), which also included Pratt & Whitney, built a full scale test article which was tested at the P&W West Palm Beach facility with some success. DuPont’s vectoring system turned the gas turbine engine thrust with acceptable efficiency. Unfortunately, duPont’s composite material curing process did not result in adequate temperature survivability and the structure lacked adequate strength.
circle-5 said:Keep your eyes open for an article on the DuPont DP-1 and DP-2 in the April-May 2014 issue of the Smithsonian's Air & Space magazine.
Archibald said:Is it just me, or are there some strinking similarities between the X-30 and DP-2, both expensive boondoggles ?
Very few engines that adopt 360 airflow turning. Must have been an interesting motivation.VTOLicious said:
You can read it hereSKYBLAZER - Keep your eyes open for an article on the DuPont DP-1 and DP-2 in the April-May 2014 issue of the Smithsonian's Air & Space magazine.
Very interesting. We all knew it was a disaster, but this sheds some new light as to how much... Thanks a lot for sharing.Archibald said:Some interesting articles shedding light on the DP-2 boondoggle
It is worth noting that it is a little unfair to attribute Mr. Hunter's support purely to campaign contributions.Archibald said:The whole story is very appalling. $63 million burned over two decades for a piece of junk that was dismissed by the Navy, DARPA and NASA altogether.
Only because Dupont fed Duncan Hunter political campaigns.My God.
As for the Orient Express - Dupont baseline weighed only 50 000 pounds. NASA doing the maths properly later (too late ?) showed that a) the plane couldn't made it to orbit, b) it had no undercarriage and c) it carried zero payload
Not to mention the vast number of would-be revolutionary bizjet designs based on Williams jets that ate up a lot of dough but never took off commercially!Archibald said:I'm suspecting that Robert Williams believed that Dupont NASP was to aircrafts what his X-wing was to helicopters: the beginning of a revolution. We all know how both revolution ended.
What strikes me is that NASP ran for seven years, swallowed billion of dollars - yet the whole thing was based on a very flawed Dupont design !
OOOOPS!!! My bad! Got carried away here and went completely off... Of course it's not the same Williams, shame on me!Machdiamond said:Sam Williams is not from the same planet as Robert.