TBL10: Adverse Pressure Gradient

Reference:
----------
Marusic,I., & Perry, A. E. 1995 A wall-wake model for the turbulence 
structure of boundary layers.  Part 2. Further experimental support. 
J. Fluid Mech. 298, 389-407.

Flow summary:
-------------
Two flows, called  10APG  and  30APG, with upstream velocities of 
10m/s and 30 m/s.  Both start in zero pressure gradient  and 
are then acted upon  by an approximately constant adverse pressure gradient.

Flows develop on the 940mm wide floor of an open return blower type
wind tunnel. A contraction area ratio 8.9:1 leads to a 4.3m long 
working section  with 68 pressure tappings along the floor 
streamwise centre line. Pressure gradients are imposed by heavy 
screening at the downstream diffuser and by varying the angle of 12 
adjustable louvres in part of the working section roof. The inclination 
of the first 1.45m of the working section roof was varied 
to obtain  an approximately zero pressure gradient on the floor.

NOTE: that in these files the variables are
      x1, u1, u :  streamwise
      x2, u2, v :  spanwise
      x3, u3, w :  wall-normal 


Files:
-----
Pressure distributions are in files cpx.d10 and cpx.d30.

Mean flow data is in files 10apg.mf and 30apg.mf

Reynolds stress data from fixed hot wires is in files 10apg.rs and
30apg.rs.

Flying hot wire data is in file 10apg.fly.

Spectra are in PH11, PH13, PH22 and PH33   for
               uu     uw    vv       ww


The spectral files are scaled with inner-flow scaling. i.e they
are non-dimensionalised by U_tau (the wall shear velocity) and z
the local distance from the wall. (see section 4 of Marusic & Perry 1995). 

i.e   phi_11[k1z]/U_tau^2 versus k1z   etc  

The files are joined from three frequency bands of data and have 
been smoothed. (see section 2.2 of Marusic & Perry 1995). No truncation 
of the high wavenumber end data is done even when the signal to noise 
ratio goes to zero. The ph_13 (cospectra) results may not be fully converged
for all Reynolds numbers as an ensemble of only 20 bursts of data were taken. 
Using 20 bursts was found to be sufficient for ph_11, ph_22 and ph_33 
but from later work it was found that approximately 100 bursts are
needed for a safe result for ph_13. This is due to the more intermittent
nature of the uw signal.

The naming convention is as follows:

eg             suu3515_0.069


  uu => streamwise spectra,  				=   phi_11
	  alternatives are:  
	vv => spanswise spectra 			=   phi_22
	ww => wall-normal spectra 			=   phi_33
	uw => cospectra (Reynolds shear stress spectra) = - phi_13


 3515 => this identifies the station and flow. The number is
	in fact the Karman number. See table 1 Marusic & Perry
	for details of which Karman number corresponds to
	which flow. Each of the 6 stations for 10APG and
        30APG are included.


 0.069 => this is the z/delta_c level at which the measurement
          was taken.