I don't have TDK, the Two Dimensional Kinematic software package, but the nozzle shapes it creates are logarithmic, not parabolic. (A licensed TDK user shared an output file with me.) I've never been able to go from Rao's paper to an actual set of equations to design a nozzle, but I strongly suspect that the best fluid dynamic shape is indeed logarithmic. I don't know what method TDK uses, but a brute force finite element analysis with an evolutionary algorithm will probably converge on the same shape.
Bottom line, one of these days I have to buy and learn to use TDK. On 11/12/2013 2:23 PM, Ed LeBouthillier wrote:
-----Original Message-----From: Ben Brockert <wikkit@xxxxxxxxx> Sent: Nov 12, 2013 11:35 AM To: "arocket@xxxxxxxxxxxxx" <arocket@xxxxxxxxxxxxx> Subject: [AR] Nozzle shapes Anyone have further info to back this up, or Russian nozzle design logic translated into English?Well, based on the drawing on this page http://www.lpre.de/energomash/RD-107/ , the RD-107 used a radius to describe the nozzle shape. Maybe other engines are doing the same.... Cheers, Ed L
