p v perturbation static pressure fluctuation due to v; 



Q transport rate 



/ Tl \ 



k R uv turbulent shear stress spectrum I dimensionless form = / I 



R Reynolds number 



R e Reynolds number based on "turbulent kinematic viscosity," 



T total shear stress 



T Q mean skin friction stress 



T T mean turbulent shear stress 



T L mean viscous shear stress 



U, V, W cartesian velocities in x, y, z directions respectively 



U, V, W mean velocities 



u, v, w velocity fluctuations [= (U — U), (V — V), (W — W)\ 



Uj velocity fluctuation in x } direction 



-V 



£/* "friction velocity"| ^ 



P 

 v i perturbation velocity fluctuation in x ; direction 



x, y, z cartesian coordinates 



Xi cartesian coordinates (i — 1, 2, 3) 



yU* 



y* = 



V 



«Bi (Ti principal directions 



a wave number 



§ geometrical boundary layer thickness 



A momentum diameter of round jet 



A* displacement thickness of boundary layer 



§ * displacement thickness fluctuation 



e thickness of wall layer in turbulent shear flow 



& itv characteristic spectral times 



(Q) momentum thickness of boundary layer 



# momentum thickness fluctuation 



v kinematic viscosity 



v T "turbulent kinematic viscosity" 



p density 



o-x.2 principal stresses 



t .t,l shear stress fluctuations 



$ rate of dissipation of kinetic energy 



xi/ a scalar property 



REFERENCES 



1. A. A. Townsend, The Structure of Turbulent Shear Flow, Cambridge Univ. Press, 1956. 



2. G. I. Taylor, Diffusion by Continuous Movements, Proc. London Math. Soc, A, 20 (196), 



1921. 



For a recent account of the dispersion problem, see G. K. Batchelor and A. A. Town- 

 send, Turbulent Diffusion, Surveys in Mechanics, the G. I. Taylor 70th Anniversary 

 Volume, Cambr. Univ. Press, 1956; for remarks on the connection with gradient trans- 

 port, see S. Corrsin, Heat Transfer in Isotropic Turbulence, Jour. Appl. Phys. 23 (1), 

 1952 and Remarks on Turbulent Heat Transfer, Proc. Iowa Thermodynamics Sympos., 

 State Univ. of Iowa, April, 1953. 



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