Abstract: To meet the demand for optical characteristic data of near-space hypersonic cruise vehicles for the detectability analysis of space-based infrared early warning satellites and the design of future space-based infrared early warning satellitesthe flow-field parameters, body temperature, infrared radiation spectrum, infrared radiation luminance, and infrared radiation intensity of the hypersonic cruise vehicle like X-51A under the typical flight condition are studied based on the combined computation and analysis methods of hypersonic aerodynamics, combustion theory, heat transfer theory, gas radiation theory, and so on. The calculated results show that the radiation features of the hypersonic cruise vehicle like X-51A are influenced by the flight time and ballistic. The infrared radiation of the body is influenced obviously by the aerodynamic heating. The jet flame radiation of the vehicle using aviation kerosene as fuel has strong radiation band of CO₂, H₂O and CO with wavelength of 1.52 μm, 2.68 μm and 4.39 μm. The jet flame radiation contributes most to the total narrow-band radiation, including the strong characteristic radiation spectra of CO₂, H₂O and CO molecule. The body radiation of the vehicle dominates the total radiation at the wavelength band which doesn’t include the characteristic radiation spectra of CO₂, H₂O and CO molecule.

Key words: hypersoniccruisevehicle, jetflame, infraredspectrum, infraredradiationintensity