Infrared emissivity, of the plume and the relative nozzle of an airplane-rocket, is a key issue for its observability and signature. Therefore, an accurate estimation, in particular in the 3,5-5[μm] and 8-12[μm] range, is mandatory.

This analysis increases significantly the level of mathematically complexity due to the integro-differential equations that characterize the radiative terms in the Navier-Stokes eqs.

Researching on infrared signature has been carried out due to a Supranational Research Project in collaboration with Industries and Institutions.

The following figures report, as an example, the infrared intensity of carbon-dioxide, carbon monoxide and water vapour, at two different altitudes.

Some documents, i.e. technical reports and deliverables, have been produced but are not available.