Fig. 21: OPD results of a hypersonic optical window with film cooling14.
From: Research progress on aero-optical effects of hypersonic optical window with film cooling

a Result of total OPD. b Result of high-order component of total OPD
From: Research progress on aero-optical effects of hypersonic optical window with film cooling
a Result of total OPD. b Result of high-order component of total OPD