To study the flow and heat transfer characteristics of transcritical methane in regenerative cooling channel of liquid oxygen/methane rocket engine

and acquire the influence of large-scale sudden expansion and sudden contraction of cooling channel on cooling effect

the three-dimensional coupled heat transfer of thrust chamber was simulated with the whole field direct coupling approach

and the flow of hot gas with non-equilibrium chemical reactions was considered in simulation. Through computation

the three-dimensional temperature field and flow field of thrust chamber were obtained. The computational results show that the maximum value of hot gas side wall temperature appears upstream the throat

because powerful secondary flow exists near the throat section. Due to strong vortices in sudden expansion and sudden contraction sections

the turbulence intensity of coolant is enhanced

the heat transfer coefficient of coolant side wall is significantly increased

the local minimum value of hot gas side wall temperature and large local loss are generated. Most of heat from combustor is absorbed by coolant on the bottom surface and side surface inside the cooling channel

because thermal resistance of copper liner is much smaller than that of nickel jacket. The axial variation of temperature and heat flux on bottom surface is more violent than that on top surface.