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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.

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