TBL30: Boundary Layer with surface Curvature

References:
 Paul Johnson, PhD thesis, Stanford University, 1990.

JOHNSON, P.L. & JOHNSTON, J. P. 1989 The effects of grid-generated turbulence on flat and 
concave turbulent boundary layers. Report MD-53 Dept. of Mech. Eng. Stanford University.

The test facility is a free surface water channel consisting of an asymmetric 4:1 contraction, a 
4.88 m long straight development section with dimensions 25 cm (width) by 1.25m (span), a 90 degree 
constant radius curved wall (R = -136 cm), and a straight recovery section.  The channel walls are 
contoured to minimize pressure gradient in the straight development section and along the concave test 
surface.  The boundary layer is tripped 1 m downstream of the nozzle exit using a .476 cm square rod. 

 Spanwise surveys show good spanwise uniformity; specifically, the roll cells which appear in the 
curved section are not fixed in space, but are randomly distributed in space and time. LDV 
measurements of all three velocity-component were made down to y+ = 5 approx, u' and w' at even 
smaller y+.

Nomenclature

x	streamwise distance, relative to the start of curvature

d, delta	boundary layer thickness, based on U = .99Ue

Upw	free-stream velocity (flat plate cases) or wall potential velocity (curved cases)

utau	wall friction velocity

nu	kinematic viscosity

theta	momentum thickness

shape factor	ratio of momentum thickness to displacement thickness

y+	distance from wall non-dimensionalized by utau and nu

U	mean velocity

Up	local potential velocity, = Upw(1+y/R)

Uc	modified mean velocity, = U(1+y/R)

Uc+	Uc non-dimensionalized by utau

u',v',w'	rms fluctuating streamwise, normal, and spanwise velocity

u'v'	Reynolds shear stress

Ruv	shear stress correlation coefficient

a1	structure parameter, = u'v'/(u'u'+v'v'+w'w') 

uuu,uuv,etc.	velocity triple products

uskw,vskw,wskw	skewness factors for u, v, and w

uflt,vflt,wflt	flatness factors for u, v, and w


	Each case has two data sets, for example CN601 and CN602.  Files with suffix 1 contain 
mean, rms, and Reynolds shear stress profiles; files with suffix 2 contain profiles of triple products and 
skewness and flatness factors.

	The five data sets are for naturally developing velocity profiles, with no grid-generated 
turbulence present.

FN	Measurements at x=-56 cm

CN15	Measurements at the 15 degree station, x=35.5 cm 

CN30	Measurements at the 30 degree station, x=71 cm

CN45	Measurements at the 45 degree station, x=106.5 cm 

CN60	Measurements at the 60 degree station, x=142 cm 


Channel "width" w, normal to test surface,and collected profile data.
x (cm)  w(cm)
-366.0   24.92
-244.0   25.66
-122.0   26.32
 -69.0   26.61
   2.0   25.52      
  20.0   24.21
  45.0   24.54
  71.0   24.67
  96.0   24.68
 122.0   24.82
 147.0   25.32
 172.0   25.36

x (cm)  Upw (cm/s)  Utau    cf
 -56      15.19     0.690  0.00413
  35      15.32     0.715  0.00436
  71      15.12     0.735  0.00473
 107      15.05     0.755  0.00503
 142      15.26     0.790  0.00536