Confined jet impingement boiling in nose cone cooling channels with different cross-sectional shapes under vibration

This study numerically investigated jet impingement boiling in nose cone cooling channels with varying cross-sectional shapes under vibration excitation. An aerothermal quasi-coupled framework and a sinusoidal displacement model were employed to capture the non-uniform thermal and vibration conditions characteristic of high-speed flight, while the Rensselaer Polytechnic Institute (RPI) wall boiling model was utilized to resolve two-phase flow and heat transfer. Four channels were analyzed under the equal temperature-difference scheme, and their cooling performance was evaluated at various magnitudes and directions of vibration acceleration. Results demonstrated that the wall temperature differences among the circular, hexagonal, and chamfered rectangular channels were within 5 K. When the acceleration in the z-direction reached 320 g, the circular channel showed the strongest response, with wall superheat reduced by 3.2 K and heat transfer resistance decreased by 34.6%. In all channels, the arc segments were dominated by evaporation heat flux, while in the tapered segments of the circular and chamfered rectangular channels, quenching prevailed at low acceleration and liquid convection dominated at high acceleration. At a constant acceleration of 40 g, x-direction vibration significantly enhanced flow disturbance and bubble departure, reducing the wall superheat of the circular channel by 3.5 K and 4.1 K in the arc and tapered segments, respectively. Meanwhile, the pressure drop decreased markedly for all channel geometries. In contrast, the rhomboidal channel demonstrated superior stability by maintaining superheat variations within 1 K across vibration directions, a phenomenon attributed to the optimal symmetry of its cross-sectional secondary flow.