This document summarizes numerical simulations of hypersonic flows using the space-time CE/SE method. It examines shock standoff on spheres in air at velocities of 8.73 km/s using a 7-species air model. It also compares experimental and numerical results for the Radio Attenuation Measurement (RAM-C) hypersonic flight experiments from the 1960s, looking at electron number densities along the vehicle surface. Distributions of species like O2, N2, and NO+ around the experimental capsule are also shown from the simulations.

1. Numerical Simulation of Ionized Hypersonic
Flows using the Space-Time CE/SE Method

2. Hypervelocity shock standoff on spheres in
air

3. Zander, F., R. J. Gollan, P. A. Jacobs, and R. G. Morgan.
"Hypervelocity shock standoff on spheres in air." Shock
Waves 24, no. 2 (2014): 171-178.
Velocity 8.73±0.14 km/s
Temperature 2013.4 K
Density 1.38E-3 kg/m3
• Sphere Diameter 0.04 m, 0.06 m, 0.08 m
N2 N O2 O NO NO+ e-
0.7866 0.0 0.2051 0.002 0.0063 0.0 0.0
Park’s 7-Species
Comparison vs. Zander et al. experiments
Freestream Conditions

4. Comparison of numerical and experimental shock
standoff.

5. Numerical Results
RAM C - II

6. Simulation Model and Test Cases
• The Radio Attenuation Measurement (RAM-C)
experiment was a series of hypersonic flights performed
in the 1960’s to study communications blackout.
• Maximum electron number densities along the direction
normal to the vehicle surface are compared to flight data
and numerical simulations done by Candler &
MacCormack
Park, C., Nonequilibrium hypersonic aerothermodynamics, Wiley, 1990.

7. 7 Species
24 Reactions
Park, Chul. "Assessment of two-temperature
kinetic model for ionizing air." Journal of
Thermophysics and Heat Transfer 3, no. 3
(1989): 233-244.
Freestream Conditions and Chemical
Model
Altitude Mach
ρ∞
(kg/m3)
u∞
(m/s)
T∞
(K)
71km 23.9 2.7E-04 7650 254K
N2 O2
0.79 0.21

8. Electron number density comparisons along the body for RAM-C
II flight test at 71 km altitude

9. Distributions of O2 and N2 around the capsule at an
altitude of 71 km.

10. Distribution NO+ around the capsule at an altitude of
71 km.