TY - JOUR
T1 - On the Mean Flow Behaviour in the Presence of Regional-Scale Surface Roughness Heterogeneity
AU - Yang, Xiang
N1 - Publisher Copyright:
© 2016, Springer Science+Business Media Dordrecht.
PY - 2016/10/1
Y1 - 2016/10/1
N2 - A suite of large-eddy simulations of the neutral atmospheric boundary layer is conducted to study the mean flow response to the presence of surface roughness heterogeneity at regional scales (surface roughness heterogeneity on the scale of several boundary-layer heights). The roughness heterogeneity is imposed using alternating rough wall patches with numerically resolved rectangular roughness elements of different packing densities. The flow near the surface is found to adjust rapidly, reaching equilibrium conditions at distances on the order of a single inter-roughness element spacing. Despite the regional heterogeneity in surface roughness, it is often desirable to parametrize the entire rough wall using one single effective roughness height. To develop such a parametrization the model of Bou-Zeid et al. [Water Resources Research 40(2):1, 2004] is extended to incorporate the displacement height, d. Predictions from this parametrization are compared with the simulations, with reasonably good agreement.
AB - A suite of large-eddy simulations of the neutral atmospheric boundary layer is conducted to study the mean flow response to the presence of surface roughness heterogeneity at regional scales (surface roughness heterogeneity on the scale of several boundary-layer heights). The roughness heterogeneity is imposed using alternating rough wall patches with numerically resolved rectangular roughness elements of different packing densities. The flow near the surface is found to adjust rapidly, reaching equilibrium conditions at distances on the order of a single inter-roughness element spacing. Despite the regional heterogeneity in surface roughness, it is often desirable to parametrize the entire rough wall using one single effective roughness height. To develop such a parametrization the model of Bou-Zeid et al. [Water Resources Research 40(2):1, 2004] is extended to incorporate the displacement height, d. Predictions from this parametrization are compared with the simulations, with reasonably good agreement.
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U2 - 10.1007/s10546-016-0154-9
DO - 10.1007/s10546-016-0154-9
M3 - Article
AN - SCOPUS:84965010323
SN - 0006-8314
VL - 161
SP - 127
EP - 143
JO - Boundary-Layer Meteorology
JF - Boundary-Layer Meteorology
IS - 1
ER -