Experiment on Drag Enhancement for a Blunt Body with Electrodynamic Heat Shield

Thermochemical nonequilibrium modeling of a low-power argon arcjet wind tunnel

“…8 The anode consists of a conical convergent part with a half-angle of 45 , a constrictor with a length and diameter of 3 mm, and a conical nozzle with an area ratio of 100, a half-angle of 25 , and a length of 29 mm. The cathode is a cone with a half-angle of 24 and a bottom with a diameter of 14 mm.…”

“…To avoid numerical instability resulting from the concentration of current on a point, the cathode tip is rounded to a hemisphere with a radius of 1 mm, whose size is estimated from the erosion around the cathode tip after several arcjet operations in the experiment. 8 The gap separating the cathode tip and the constrictor inlet is set at 4 mm, which is equal to the value in the experimental setup. 8 The total points inside the arcjet are ðn  gÞ ¼ ð395  100Þ in the n and g directions (see Fig.…”

“…Figure 2 shows a photograph of a blunt body in the arc plume. 8 The distribution of the plume luminosity implies that this small plume has comparable diameter to that of the body and has a non-uniform flow structure in the radial direction. Consequently, the uniform free-stream assumption is inappropriate for the plume.…”

“…Particularly, the authors 5-8 have used a 1-kW-class argon arcjet wind tunnel to investigate electrodynamic flow control, which is a promising alternative to conventional thermal protection systems used for atmospheric entry vehicles. To evaluate quantitatively the electrodynamic flow control in these experiments, Kawamura et al 8 measured the drag exerted on a blunt body with an embedded magnet in the arc plume, and found that the electrodynamic force increased drag. To validate this measurement, Katsurayama et al 9 attempted direct simulation Monte Carlo (DSMC) and Navier-Stokes computations under the simple assumption that the blunt body is exposed to a spatially uniform plasma flow with measured flow properties (i.e., a free stream with constant electric conductivity).…”

“…The resulting clarification of the arc plume structure and properties is necessary to validate measurements obtained in electrodynamic flow control tests. 6,8 …”