Numerical analysis of a gas veil cooling system for high-aspect-ratio transonic cylindrical channels

High-elongation transonic channels distinguished by the high thermal loading of the walls are widely used in modern power plants. To ensure the operability of structural elements of such channels is a scientific and technological challenge. This is particularly important for small power plants. In many cases, classical cooling flows do not comply with technological requirements, complicate the design, increase construction costs, or unacceptable according to specifications. One of the possible implementations of the thermal protection system is the veil cooling. However, the scientific literature pays little attention to the decay mechanisms of transonic channel veil cooling taking into account ejection, viscosity, and shockwave effects. In this study, the mathematical modeling of a high-elongation channel veil cooling is performed and its characteristics are determined. The calculating dependences are established to assess the length of decomposition regions for the veil layer and the flow core, the dynamics of mixture of the blown-in and main flows, as well as the level of heat flows in the channel wall. The results of research can be used in designing high-temperature tracts and exhausts of gas generators, nozzles of technological installations, and mixing and afterburning chambers.

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