Influence of a Counterflow Plasma Jet on Supersonic Blunt-Body Pressures

Abstract

Aerodynamic augmentationin the presence of a thin high-temperature onboardplasma jet directed upstream of a slightly blunted cone was studied experimentally and numerically. The ow around a truncated cone cylinder at zero incidence was considered for Mach numbers M 1 = 2:0, 2.5, and 4.0. For the rst time, computationally validated experimental pressure distributions over the model surface in the presence of the plasma jet were obtained. As in the conventional (nonplasma) counter ow jet, two stable operational regimes of the plasma jet were found. These were a short penetration mode and a long penetration mode (LPM) aerospike into the opposing supersonic freestream. The greatest drag reduction occurred in the moderate LPM regime. LPM strong overblowing reduces the bene ts. The experimental pressure results were approximately validated against an Euler computational uid dynamics simulation,modeling a perfect gas hot jet, counter owing againsta perfect gas supersonic freestream. Plasma effects such as electron pressure, radiation, electric eld interactions, Joule heating, and induced vorticity, streamers, and plasmoids have been identi ed that, if accounted for, may improve the comparison. Procedures for the use of these experimental results have been outlined as a baseline that will be useful in separating uid dynamic/thermal effects from plasma processes in understanding the physics of onboard plasma jets for aerodynamic augmentation.

A Survey of Supersonic Retropropulsion Technology for Mars Entry, Descent, and Landing

“…The Euler solver was able to capture the reduction in body surface pressures caused by transition to unstable flow and jet penetration of the bow shock. The relatively good agreement seen between the Euler solutions and the experimental plasma jet work suggests much of the interactions at lower supersonic Mach numbers resemble retropropulsion gas dynamics, a result promising for future work with combusting retropropulsion effects [44]. Additional work from the same authors has been reported to have had success with modeling supersonic retropropulsion in the form of plasma jets, using the assumption of a perfect gas with constant specific heats [45].…”

“…Recent work has focused on drag reduction for slender body vehicles, not drag augmentation for blunt bodies, and the effects of high temperature plasma jets on the body aerodynamics [44], [45]. However, the similarities in flowfield interactions between these applications and supersonic retropropulsion for EDL have been useful in extending computational approaches.…”

“…Additionally, oscillatory behavior, characteristic of even stable flowfields, makes starting solutions and defining convergence difficult. Despite these challenges, several studies [21], [37], [44], [45] have shown varying degrees of success in modeling the aerothermodynamics of single nozzle configurations.…”

“…Fomin and Maslov [44] performed numerical simulations in support of experimental work on the blunt-body pressure effects of a high temperature plasma jet at freestream Mach numbers of 2.0, 2.5, and 4.0. Composition of the freestream was air, and the plasma jet was nitrogen gas at 5000 K. The experimental results were compared against an Euler CFD analysis in an effort to understand the separation existing between fluid dynamics and the thermal processes in a supersonic freestream-propulsion interaction.…”

Forebody shock control devices for drag and aero-heating reduction: A comprehensive survey with a practical perspective

“…This feature of plasma discharge (along with other energy discharge forms) will be discussed later in this survey. To date, the studies on opposing plasma jet have been exclusive to three research groups: Gordeev et al [166,170,210,213,214], Shang et al [152,215,216], and Fomin et al [217,218].…”