Peter Stickney > On Monday 18 July 2005 18:25, Josh Babcock wrote: > > > All the 3350s had this turbo/super setup. You can see it in some of > > these images: > > > > <URL's snipped> > ... snip ... > > There were 3 flavors of the R3350. One was the engine used on the > B-29. It had a single-speed gear driven blower. The > turbosuperchargers (The B-29 used 2 per engine - basically the same > model used on the B-17 and B-24 - with twice the displacement, and > about the same RPM, it needed twice the mass flow, and using the > paired turbosuperchargers meant that they could deliver a working > system without having to interrupt production) fed air at what were > essentially sea level conditions to the engine's mechanical blower. > The production versions peaked out at about 2200 HP, and a useful Full > Throttle Height of around 25,000'.
OK, so what we have here is a 2 stage supercharger. The first stage is the 2 turbos and the second stage is the single stage gear-driven supercharger. I have enough data now for a reasonable simulation, but to make it more accurate, I wonder if you could describe the action of the supercharger pressure regulator? I can model it as just controlling the manifold pressure between 0 and full. I interpret 0.8 (#8 on the dial) as being the setting for full throttle height (military power). Settings 9 and 10 are emergency settings. Did the controller act on the throttle, or a control a wastegate to adjust the turbos, or just dump pressure, or? > But that's not the only way to do it. I've been preparing a series of > articles on supercharging reciprocating engines. Is there any > interest for me to pull some of it out and present it here? Probably not here, but personally I would be _most_ interested in anything you have on this subject. This list is a great place to learn, and this can lead to more realistic simulation. If you like, send me anything you feel like off-list, or point me to a website. I have been struck by the lack of detailed information on the web on the R3350, a stark contrast to the Merlin/Griffon. Thanks Vivian _______________________________________________ Flightgear-devel mailing list Flightgear-devel@flightgear.org http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
