Modeling and simulation of transpiration cooling with phase change

• We present a series of new conservation equations for the transpiration cooling with phase change.
• The model and numerical solution are validated by the experiments.
• The effects of coolant injection rate and external heat flux are discussed.
• The momentum modification has a significant effect on the distributions of pressure and velocity.

This paper presents a series of new conservation equations for mass, momentum and energy, to describe the performances of fluid flow, heat absorption and phase change in porous matrix. The differences from previous models include, firstly, considering the compressibility of vapor in the momentum and energy equations; secondly, adding a term of the momentum transfer caused by liquid phase change into the momentum equations of vapor and liquid phases in two-phase region; finally, in the energy equation of two-phase region, taking the variations of temperature and pressure into account, eliminating the assumptions that the enthalpy is only dependent on temperature, and saturation temperature is constant. In the application to one-dimension steady-state problem, the equations of liquid region are analytically solved, while those of two-phase and vapor regions are numerically solved. Experiments were conducted to validate the model and numerical strategy. The pressure data measured are quite identical with the simulation results. Using the validated model and numerical strategy, the effects of coolant injection rate and external heat flux on the distributions of temperature, pressure and velocity are discussed.