Analysis of Annular Plug Nozzle Flowfield

Pressure Distribution and Performance Impacts of Aerospike Nozzles on Rotating Detonation Engines

“…The open wake regime is sometimes further classified into type 1 and type 2 flows based on the location of the expansion fan along the plug contour [33], [34], [35].…”

“…Nasuti, Onofri, and Chutkey et al [21], [27], [33], [34], [37] independently present detailed engineering models for prediction of transition between wake states in both still air and supersonic flow. Essentially, the wake is said to be closed if the last characteristic wave of the expansion fan centered at the nozzle lip impinges on the wake downstream of the reattachment point [21].…”

“…It is important to note that open wake operation does not guarantee that base pressure will be equal to the local ambient pressure. Rather, operation in the open wake regime just indicates that base pressure varies in the radial direction about the ambient pressure value, depending on the prevailing pressure at the plug lip, which in turn depends on the nature of the wave interactions at lower pressure ratios [34], [33]. For annular plug nozzles in the open wake regime, base pressure has been shown to vary about the atmospheric pressure value, while for the linear plug case, the open wake base pressure can be reasonably approximated to atmospheric pressures [21], [34].…”

“…Chutkey et al [34] and Onofri et al [21] suggest that, from the viewpoint of design, it is reasonable to assume an atmospheric pressure prevails on the base surface in the open wake regime. In this case, the problem becomes predicting the transition pressure ratio at which the recirculation bubble closes, rather than predicting the nozzle base pressure.…”

Design of axisymmetric aerospike nozzle based on modified MOC

“…Four nozzles with different lengths were studies both experimentally and computational tools. The applicability of RANS method and its limitations in prediction of flow in truncated spikes were studied [26].…”