Accession Number : ADA182427

Title :   Time Resolved Measurements of Large Amplitude Velocity Fluctuations with a Three-Sensor Hot-Wire Probe,

Corporate Author : MICHIGAN UNIV ANN ARBOR DEPT OF AEROSPACE ENGINEERING

Personal Author(s) : Willmarth,W W ; Wei,T ; Madnia,K

PDF Url : ADA182427

Report Date : Nov 1984

Pagination or Media Count : 46

Abstract : Calibration and data reduction procedures are reported for a three sensor hot-wire probe used to determine all three velocity components in large amplitude turbulence at a speed of 65 ft./sec. Hot wire sensors were necessary because hot film sensors did not produce a steady, predictable signal for a large variation of the angle between the sensor axis and the stream. A digital computer was used to obtain an iterative solution of the equations relating the sensor signals to the velocity components. Reasonably accurate measurements of the time resolved velocity components were made for transverse velocities less than approximately 2/10 of the stream velocity. For larger transverse velocities, the instability of the iterative solution in conjunction with the occurrence of multiple solutions presents a serious problem. Improved methods of iteration and additional information beyond that provided by the three sensor signals appears to be necessary to determine the correct solution among a maximum of four possible solutions with flow downstream along the probe axis.

Descriptors :   *HOT WIRE ANEMOMETERS, *TURBULENCE, *THREE DIMENSIONAL FLOW, DIGITAL COMPUTERS, DOWNSTREAM FLOW, HIGH VELOCITY, ITERATIONS, PREDICTIONS, PROBES, SIGNALS, SOLUTIONS(GENERAL), STEADY STATE, STREAMS, TRANSVERSE, VARIATIONS, VELOCITY, AMPLITUDE, CALIBRATION, DATA REDUCTION

Subject Categories : Test Facilities, Equipment and Methods
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE