Deep space shuttles- Chemical vs nuclear - Direct flight vs near-orbit rendezvous

Abstract

(3) From the swirl velocities calculated from Eq. (3) for each Ap and each injection velocity, reference spin rates were calculated. Results are given in Fig. 6, which shows that, at one spin rate, J may have a substantial effect on thrust (and m). The effect is complicated: its direction and magnitude depend upon spin rate, value of J, and type of nozzle system. The reference spin rates calculated here should not be applied to systems of different scale without attention to appropriate similarity relations. Conclusions Tangential injection provided a method of studying swirling effects. The data obtained also allowed study of axial flow in multiple nozzles displaced various distances from the centerline. The data permit several significant conclusions: 1) As swirl intensity increases, both mass flow rate (m) and thrust (F) are substantially reduced. These reductions of F and m can be explained quantitatively, using one-dimensional isentropic flow theory, as being due to an effective reduction in throat area caused by development of a low-density core. 2) For a given reference spin rate, as J = A*/A P decreases (tangential velocity at the port radius increases), the effects depend on the type of nozzle system and the values of J and spin rate. 3) For flow in which swirl is essentially absent, thrust is slightly reduced as nozzles are displaced farther from the swirl chamber centerline for any /. The total thrust reduction is primarily a result of a total pressure drop. The results depict the behavior of swirling and axial flow through multiple nozzles; however, methods are needed which will permit analytical determination of vortex core size and effective throat area in multiple nozzles as the analyses of Mager2 and Norton et al. 5 have made possible for single nozzles.