Data Set Description


THREE DIMENSIONAL BOUNDARY LAYER APPROACHING A WEDGE


Data Originators: Shawn D. Anderson and John K. Eaton
Department of Mechanical Engineering, Stanford University

Primary References: 

Anderson, S.D. and Eaton, J.K. "An Experimental Investigation of Pressure Driven
Three-Dimensional Boundary Layers, Rept. MD-49, Thermosciences Division, 
Dept. of Mechanical Engineering, June 1987.

Anderson, S.D. and Eaton, J.K. "Experimental Study of a Pressure-Driven, 
Three-Dimensional, Turbulent Boundary Layer," AIAA J. Vol. 25, August 1987, 
pp. 1086-92.

Anderson, S.D. and Eaton, J.K. "Reynolds Stress Development in Pressure-Driven 
Three-Dimensional Turbulent Boundary Layers," J. Fluid Mech., Vol 202, 1989, 
pp. 263-294.

Abrahamson, S.D. and Eaton, J.K. "Heat Transfer through a Pressure-Driven Three 
Dimensional Boundary Layer," AIAA/ASME Thermophysics and Heat Transfer Conference, 
Seattle, June 1990.

General Description of Experiment:

An initially two-dimensional boundary layer was skewed and distorted by the 
pressure field ahead of an upstream-facing wedge.
This produces a strongly three dimensional boundary layer and separation ahead 
of the wedge tip.  Extensive measurements of the mean velocity and pressure 
fields document the overall flow development.   
Previous experience suggests that a computation of the entire field using the 
RANS equations is required as opposed to boundary-layer calculations.  
Therefore, the full field measurements are suggested as the primary test data.  
Additional data including the Reynolds stresses, the skin friction, and the heat 
transfer coefficient are documented along the centerline and one selected 
streamline.

Geometry Specification:

The test section consists of two parallel planes separated by 11.9 cm.  
All of the measurements were made on one of the plane walls designated as the 
"test wall".  The low-momentum region of the boundary layer on the opposite wall 
was removed by a two-dimensional scoop located at X = -14.5 cm.

The origin of coordinates is the centerline of the test wall at the beginning of 
the test section.  The total wedge angle is 90 degrees and it is positioned 
symmetrically so the freestream is turned by 45 degrees.   

The wedge tip is located at X = 51.8 cm and Z = 0 cm.  
The wedge extended to X = 121.9 cm and Z = +/- 68.6 cm.  

The pressure field was also strongly affected by the position of the fairings.  
The fairings were set by cutting a template to match a fourth-order polynomial 
then pushing the fairings into position against the fairing.  
The polynomial was:

Z = A + BX + CX^2 + DX^3 + EX^4

where Z and X are in centimeters and:

			A = 30.004 cm
			B =  0.018957
			C = -0.0036287/cm
			D =  0.00020397/cm^2
			E = -0.00000119/cm^3

The fairings extended beyond the end of the wedge.

Initial Conditions:

The first measurement station for the test-wall boundary layer was at X = 7.6 cm.   
Turbulence data is also available at this X location.
The boundary layer is mildly three dimensional by this point so the calculation 
should probably be started upstream.  The opposite wall boundary layer initial 
condition was measured at X = 2.0 cm.  The boundary layer thickness (delta99) 
was 2.64 cm, the momentum thickness Reynolds number 2654 and the skin friction 
coefficient 0.00388 at this point.  The tunnel geometry prevented easy access 
to the near-wall region of the boundary layer on the fairing.  
Initial boundary layer measurements on the fairing were difficult.  Outer layer 
measurements indicated a boundary layer thickness of approximately 5 cm.

Data Tables:

The primary measurements were all made using probes inserted through seven 
spanwise slots in the opposite wall of the test section.  
These slots are referred to as S1-S7 in the data tables and figures.  
The axial positions of the slot are shown in the following table.
------------------------------------------------------------
Slot Position

     |  S1    S2    S3    S4    S5    S6    S7  
---------------------------------------------------	
   X | 7.6   22.9  38.1  45.7  53.3  61.0  68.6   |  cm.
-----------------------------------------------------

Static Pressure:
The static pressure data are presented as the pressure coefficient.  
The data are referenced to the pressure at the centerline at X = 7.6 cm and 
normalized by the dynamic pressure at that same point.  

Mean Velocity Profiles:
All velocity data are presented in a raw form, that is no normalization has been 
applied.  An upstream reference velocity was recorded with each measurement and 
may be used to normalize the data.  Generally, the reference velocity was held 
constant within less than 1% by the automatic wind tunnel controller so no 
normalization is needed.  Mean velocity profile data were acquired using a 
conventional three hole probe along the centerline and along a freestream 
streamline beginning at X = 0 and Z = 15 cm.  

Mean Velocity Maps:
Full planes of two-component mean velocity data were acquired at 5 different Y values.  
The angle DELTA reported for each measurement is yaw angle relative to the x axis.

Heat Transfer Data:
The heat transfer coefficient was measured on a constant heat flux heat transfer 
surface.  A preheater plate was installed in the development section to produce 
a developed thermal boundary layer at the test section entrance.  The preheater 
plate began at x = -120 cm and was operated at the same heat flux as the test 
plate installed in the test section.  The typical heat flux was 630 W/m2.  
The heat flux was slightly smaller near the wedge but the variation was not significant.  
The dimensional temperature profiles were measured at the same positions as the 
velocity profiles along the selected streamline.
