Simulation study on the airflow and heat transfer characteristic in a nacelle

Five design schemes of helicopter nacelle ventilation cooling system were proposed to provide efficiently cooling for the nacelle. In order to evaluate the cooling effect of these design schemes, the characteristic of airflow and heat transfer in the nacelle was numerically calculated by a general CFD software. Unstructured mesh and finite volume method (FVM) were applied for calculation regions and governing equations discreteness, and standard k-ε model was adopted to solve turbulent governing equation. For five schemes of nacelle cooling system, the influence of cooling air inlet size, position, mass flow rate and ambient temperature under hover condition on the flow and temperature field distributions was discussed. Also transient calculations were carried out when the engine was shut down. The results provided a theoretical basis for design and optimization of nacelle ventilation cooling system.