Application of DPIV to Enhanced Mixing Heated Nozzle Flows

摘要: Digital Particle Imaging Velocimetry (DPIV) is a planar velocity measurement technique that continues to be applied new and challenging engineering research facilities while significantly reducing facility test time. DPIV was used in the GRC Nozzle Acoustic Test Rig (NATR) characterize high temperature (560 C), speed (is greater than 500 m/s) flow field properties of mixing enhanced jet engine nozzles. The instantaneous maps obtained using were determine mean velocity, rms two-point correlation statistics verify true turbulence characteristics flow. These measurements will ultimately properly validate aeroacoustic model predictions by verifying CFD input these models. have previously not been possible hot supersonic jets. Mapping nozzle point based techniques requires over 60 hours time, compared less 45 minutes DPIV, yielding significant reduction testing A dual camera configuration maximize view further minimize time required map system covered 127 267 mm. Data acquired at 19 axial stations providing coverage from exit 2.37 downstream. At each station, 400 image frame pairs camera. designs illustrate changes resulting reduced noise signature.