Drag reduction of engine exhaust system based on spray cooling
The electric heating spray cooling drag reduction test bench was used to systematically study the influence of spray flow rate,spray inclination angle,airflow temperature,and airflow speed on the drag reduction performance of the engine exhaust system.The reason why spray cooling can significantly reduce drag was revealed by DPM-based numerical simulation.The research results show that the drag reduction rate increases with the spray flow rate when the spray flow rate is between 12 mL/s and 24 mL/s.When the spray inclination angle is increased from 45° to 90°,the drag reduction first remains unchanged and then decreases.The drag reduction effect of 45° and 60° spray inclination is the best.When the airflow temperature is between 200℃and 300℃,the drag reduction rate increases with the airflow temperature.The drag reduction rate decreases gradually when the airflow velocity increases from 20 m/s to 30 m/s.The reason for the significant reduction in the drag of the exhaust system after spraying is that the airflow velocity reduces,the turbulent intensity reduces,and the local and frictional drag reduces.
NETL
NSTL
万方数据
