Aerodynamic noise reduction device

摘要

An aerodynamic noise reduction device reduces aerodynamic noise originating from a separation region located downstream of a step portion protruding from a surface of an object placed in an airflow. Since the step portion protrudes from the surface of the object placed in the airflow, aerodynamic noise is generated from the airflow separation region located downstream of the step portion. However, by forming an air discharge vent at the step portion at a position near a point, in the separation region, where a Reynolds stress is at its maximum and by discharging air from the air discharge vent toward the point where the Reynolds stress is at its maximum, the velocity gradient in the separated shear layer in the separation region is mitigated to decrease the maximum value of the Reynolds stress. The aerodynamic noise is thus effectively reduced.

主权项

1. An aerodynamic noise reduction device which reduces aerodynamic noise originating from a separation region located downstream of a step portion protruding from a surface of an object placed in an airflow, the aerodynamic noise reduction device comprising:
an air discharge vent formed at the step portion at a position near a point, in the separation region, where a Reynolds stress is at a maximum, and the air discharge vent is formed and positioned so as to direct air discharged therefrom to the point in the separation region where the Reynolds stress is at the maximum, wherein air is discharged from the air discharge vent toward the point where the Reynolds stress is at the maximum.