To alleviate the serious temperature and pressure environment of the forebody of hypersonic vehicle

the combined drag and heat reduction scheme of spike and opposing jet was studied in depth. The Reynolds averaged Navier-Stokes equations were solved based on the finite volume method

and the shear stress transport k -ω turbulence model was used. The conjugate heat transfer method was used to solve the heat conduction equation of solid domain. Results showed that the application of the opposing jet significantly improved the performance of drag and heat reduction. The drag coefficient of blunt forebody decreased significantly with the increase of spike length. With the length-to-diameter ratio of the spike increasing from 0.5 to 2.0

the drag coefficient decreased to about 21%. The peak value of heat flux was almost unaffected. Increasing the total opposing jet pressure ratio can significantly reduce pressure on the blunt forebody surface. Considering the additional drag induced by the opposing jet

as a result

the drag reduction effect became worse. With the total opposing jet pressure ratio increasing from 0.4 to 0.8

the peak value of heat flux on the blunt forebody surface decreased by 62.5%. The result of conjugate heat transfer analysis shows the temperature of blunt forebody increases significantly with time

and the peak value of heat flux decreases slowly with time.