A comparative study of plane and radial turbulent wall
jetsSpeaker: William LinAdvisor: Prof. Eric
SavoryAffiliation:Sponsors:1Outline1. Introductory remarks Overview
of two configurations Motivation Objectives2. Plane wall jet
velocity measurements3. Comparison of plane and radial wall jets4.
Closing remarks2Brief overview of the plane wall jetbtInner
layerOuter layer3Open exitOpen slot topYBrief overview of the
radial wall jet4rimpingement regimeywall jet regimeAxis of symmetry
nozzleDOpen exityDMotivationApplications: heating/cooling or
drying/wetting removal or deposition of particles/films protective
fluid layer modelling of storm outflows5Objectives To take velocity
measurements of the plane turbulent wall jet To compare available
experimental results from plane and radial wall jets.6Co-ordinate
systemxyzZUVW7YNomenclatureUm/2 y0.5ymUm Ujbt8Experimental
set-upbt/b = 1/9Y/b = 19x/b = 50 to 208wire mesh9Experimental
set-upWire mesh 16 x 16 openings/in2 Dwire= 0.46 mm open area =
50.7%10Measurement apparatusDantec MiniCTA 54T30 system sampling
frequency = 1 kHz55P61 x-wire probe wire diameter = 5 x 10-6m wire
length = 1.25 x 10-3mCalibration Pitot-static tube + U-tube
manometerTraverse accuracy = 0.2 x 10-3mNI PCI-6071E card 12-bit
resolution11Uncertainty analysisPropagation-of-uncertainties
approach(Wheeler & Ganji 1996)U = f(A, B, C, )2 / 12 2
2...(((
+||
\|+||
\|+||
\|= CCUBBUAAUU12Uncertainty analysisSources of uncertainty
considered: Random variation of the measurand Ambient temperature
variations during measurements Potential x-wire probe misalignment
( 2) Potential pitot-static tube misalignment ( 2) A/D conversion
uncertainties Scale readability limitation of the calibration
manometer Calibration curve-fitting X-wire probe yaw coefficient
uncertainties 13Uncertainty analysisU [m/s] U [%]41 3.237 3.331
3.428 3.524 3.720 4.115 4.312 4.87.9 6.15.0 8.414Plane wall jet
velocity profiles00.10.20.30.40.50.60.70.80.911.11.20 0.05 0.1 0.15
0.2 0.25 0.3Iu = uRMS/Umy/y0.5x/b=50x/b=150Wygnanski et al.
(1992)Present studyStudy Rebx/b t/b Y/b similarity?Present study
4.0E+04 50, 150 0.1 21 noWygnanski et al. (1992) 1.9E+04 60 to
120
