Gas dynamics of a rocket plume in the upper atmosphere

We study the expansion of a rocket exhaust plume in the direction perpendicular to the rocket motion. We compare numerical calculations with a self-similar approximation for a strong cylindrically symmetric explosion and show that, if the rocket velocity V ∞ is high enough and exceeds the sum of the exhaust gas velocity V e and the sound velocity V s (V ∞ > V e + V s ), a gasdynamic hole may be formed for a short time around the rocket flight trajectory in the upper atmosphere, where the plume-gas concentration is less than the ambient-gas concentration at a given altitude. We calculate the density and temperature profiles of the transversal plume expansion.