Averaging procedures for flow within vegetation canopies

✍ Scribed by M. R. Raupach; R. H. Shaw

• Publisher: Springer
• Year: 1982
• Tongue: English
• Weight: 758 KB
• Volume: 22
• Category: Article
• ISSN: 0006-8314
• DOI: 10.1007/bf00128057

✦ Synopsis

Most one-dimensions models of Now within vegetation canopies are based on horizontaiIy averaged flow variables. This paper formalizes the horizontal averaging operation. Two averaging schemes are considered: pure horizontal averaging at a single instant, and time averaging followed by horizontal averaging. These schemes produce different forms for the mean and turbulent kinetic energy balances, and especially for the 'wake production' term describing the transfer of energy from large-scale motion to wake turbulence by form drag. The.differences are primarily due to the appearance, in the covariances produced by the second scheme, of dispersive components arising from the spatial correlation of time-averaged flow variables. The two schemes are shown to coincide if these dispersive fluxes vanish.

Boundary Layer h4eteorology 22 ( 1982) 79-90.