  Two kinetic models are proposed for high-temperature rarefied (or
non-equilibrium) gas flows with radiation. One of the models uses the Boltzmann
collision operator to model the translational motion of gas molecules, which
has the ability to capture the influence of intermolecular potentials, while
the other adopts the relaxation time approximations, which has higher
computational efficiency. In the kinetic modelling, not only the transport
coefficients such as the shear/bulk viscosity and thermal conductivity but also
their fundamental relaxation processes are recovered. Also, the non-equilibrium
dynamics of gas flow and radiation are coupled in a self-consistent manner. The
two proposed kinetic models are first validated by the direct simulation Monte
Carlo method in several non-radiative rarefied gas flows, including the normal
shock wave, Fourier flow, Couette flow, and the creep flow driven by the
Maxwell demon. Then, the rarefied gas flows with strong radiation are
investigated, not only in the above one-dimensional gas flows, but also in the
two-dimensional radiative hypersonic flow passing cylinder. In addition to the
Knudsen number of gas flow, the influence of the photon Knudsen number and
relative radiation strength is scrutinised. It is found that the radiation can
make a profound contribution to the total heat transfer on obstacle surface.
