Regenerative cooling of a liquid rocket engine using computational fluid dynamics and conjugate heat transfer

Regenerative cooling is a method used for cooling liquid fuel rocket engines. To cool the engine walls, the liquid fuel (oxidizer in some engines) passes through the cooling channels in the walls, allowing the wall to cool down along the engine and preventing the walls from reaching the temperature at which they may be damaged. In general, the most critical location is the throat region of the convergent-divergent nozzle, where the highest heat flux occurs. With this method, which is called regenerative cooling, the temperature of the fuel passing through the channel continuously increases up to the injector, thus increasing the internal energy of the fuel, which has a positive effect on combustion efficiency and stability. However, the regenerative cooling process causes the fuel pressure drop passing through the channel. For these reasons, to achieve the best efficiency in the regenerative cooling process, low pressure loss and low wall temperature should be targeted. Wadel and Meyer's studies are used to validate simulations. In the regenerative cooling analyzes, time-independent 3D, turbulence Computational Fluid Dynamics was solved using different turbulence models and conjugate heat transfer model using commercial software. The heat flux resulting from the combustion hot gas mixture was modeled using the Bartz equation. For regenerative cooling analyzes, the studies in the literature are examined and compared with the experimental results. After the validation study, the cooling effects of the differences from the nominal mass flow rate originating on the fuel manifold are investigated. In case of blockage of one of the regenerative cooling channels, temperature changes in the wall of rocket engine are studied. Additionally, the effects of different geometric configurations on cooling were investigated for the number and aspect ratio of the cooling channels.