A 2-D numerical model of boundary-layer flow over single and multiple surface condition changes

Abstract Based on the 1-D planetary boundary layer model of Weng and Taylor with E – l turbulence closure, a 2-D numerical model is developed to study the atmospheric boundary-layer flow over single or multiple changes in surface conditions. These changes can include surface roughness, thermal and moisture properties. A constant flux wall layer is used within which approximate forms for the velocity, temperature, moisture and turbulent kinetic energy profiles are obtained by analytic solution with the assumption of production equal to dissipation of turbulent kinetic energy. We also use a simple, analytic model dealing with the surface roughness change effects in neutral stratification based on the concept of an internal boundary layer. Model results for roughness changes are discussed and compared with other models and published field data.

[1]  Niels Otto Jensen,et al.  Change of surface roughness and the planetary boundary layer , 1978 .

[2]  P. Mason,et al.  A two-dimensional numerical study of horizontal roll vortices in the neutral atmospheric boundary layer , 1980 .

[3]  H. Cheng,et al.  Near-Wall Flow Development After A Step Change In Surface Roughness , 2002 .

[4]  E. F. Bradley.  A micrometeorological study of velocity profiles and surface drag in the region modified by a change in surface roughness , 1968 .

[5]  S. Arya,et al.  Dispersion in neutral boundary layer over a step change in surface roughness. I: Mean flow and turbulence structure , 1984 .

[6]  P. Taylor,et al.  Some comparisons between observed wind profiles at Risø and theoretical predictions for flow over inhomogeneous terrain , 1973 .

[7]  W. Elliott,et al.  The growth of the atmospheric internal boundary layer , 1958 .

[8]  E. W. Peterson,et al.  Modification of mean flow and turbulent energy by a change in surface roughness under conditions of neutral stability , 1969 .

[9]  S. R. Karpik,et al.  An improved method for integrating the Mixed Spectral Finite Difference (MSFD) model equations , 1988 .

[10]  J. Moum,et al.  Small Scale Processes in Geophysical Fluid Flows , 2001 .

[11]  Erik Lundtang Petersen,et al.  The European Wind Atlas , 1985 .

[12]  C. Shir.  A Numerical Computation of Air Flow over a Sudden Change of Surface Roughness , 1972 .

[13]  Y. Delage,et al.  A numerical study of the nocturnal atmospheric boundary layer , 1974 .

[14]  A. Lo.  On the boundary-layer flow over a Canadian Archipelago polynya , 1986 .

[15]  J. Garratt.  The Atmospheric Boundary Layer , 1992 .

[16]  J. C. Kaimal,et al.  Atmospheric boundary layer flows , 1994 .

[17]  N. A. Jackson.  The propagation of modified flow downstream of a change in roughness , 1976 .

[18]  J. Wyngaard,et al.  The Structure of the Two-Dimensional Internal Boundary Layer over a Sudden Change of Surface Roughness , 1974 .

[19]  Hans A. Panofsky,et al.  Change of terrain roughness and the wind profile , 1964 .

[20]  P. Taylor,et al.  The Planetary Boundary Layer above a Change in Surface Roughness , 1969 .

[21]  P. Taylor,et al.  On Modelling the One-Dimensional Atmospheric Boundary Layer , 2003 .