Effect of the length of truncated nozzle with a tip on its thrust characteristics

Nowadays, for solving new problems, rocket engine nozzle developers are increasingly turning to non- traditional configurations that differ from the classic Laval one. A relatively line in design of supersonic nozzles is development so-called bell-shaped nozzle, which, unlike classical has a larger angle entry into part nozzle. In this case, dual bell nozzles, which have two flow expansion sections their part, considered. However, effect length ratio truncated on its characteristics not yet been studied. The goal work determine upstream conical section static pressure distribution and thrust with shape tip kept unchanged. were studied using ANSYS Fluent computing package. It was shown patterns (velocity fields) change underexpansion degree. Under terrestrial conditions (Pн = 1 bar), all variants show developed separation zone starts corner point where connected part. wall nearly equal ambient pressure. At large degree (P0 300 bar) low-pressure =0.1 adjacent wall. degree, increases exit, at exit decreasing length. coefficient decreases increasing it reaches constant value after becomes downstream high degrees, higher longer calculated results good agreement experimental data type.