Accession Number : ADP008941

Title :   Spectral Characteristics of Velocity and Wall Pressure in a Ducted Flow with Dual Side and One Axial Inlets,

Corporate Author : NATIONAL TSING HUA UNIV HSINCHU (TAIWAN)

Personal Author(s) : Liou, T. -M. ; Wu, Y. -Y.

Report Date : 23 JUL 1992

Pagination or Media Count : 6

Abstract : The velocity and wall pressure spectral characteristics of the impingement of multiple inlet jets is a ducted flow was investigated experimentally using LDV and microphone, respectively. The baseline momentum ratio of the axial- to side-inlet jet (MR) was chosen to be 0.27. In this case, a resonant feedback frequency of 365 Hz, which prevailed in the entire combustor, and the second and the third harmonics, which appeared near the impingement region, were observed. Also, the effect of the MR on the flow oscillations was studied and the results showed that below NR=0.94, a constant Strouhal number, based on the axial inlet velocity and width, of 0.013 was found; is other words, the frequency of the oscillations was triggered by the coupling between the disturbance feedback frequency and the acoustic frequency of the settling chambers of the side inlets. (Author)

Descriptors :   *DUCT INLETS, *JET FLOW, *LASER VELOCIMETERS, *DOPPLER EFFECT, FLOW NOISE, SPECTRUM ANALYSIS, STROUHAL NUMBER, SOUND PRESSURE, PRESSURE DISTRIBUTION, TAIWAN.

Subject Categories : Fluid Mechanics
      Electric and Ion Propulsion
      Optical Detection and Detectors

Distribution Statement : APPROVED FOR PUBLIC RELEASE