Turbulence measurements of a personal airflow outlet jet in aircraft cabin

摘要

The jet airflow field of MD-82 aircraft cabin's personal airflow outlet (PAO) is measured by constant-temperature anemometry system with the resolution higher than the smallest time-scale of turbulence. The turbulence statistics at different radial and axial positions is analyzed. The airflow field of the PAO jet is similar to a single jet beyond the point of reattachment. However, the airflow diffuses stronger than the single jet, turbulence intensity is higher, each order turbulence statistics and characteristics scales get turbulent equilibrium earlier. The inertial sub-range is found by spectrum analysis, by which the energy is cascaded from the energy-containing large scale to the small scale, and finally dissipated into heat. Moreover, wavelet analysis is employed to perform multi-scale decomposition of instantaneous turbulence fluctuating velocity signals, in order to accurately distinguish the time scales which dominate the airflow field.