Author(s): A. M. Ricardo
Linked Author(s):
Keywords: Emergent rigid vegetation; Double-Averaging Methods; Velocity maps; Optimization algorithm
Abstract: In engineering applications concerning the flow in vegetated channels such as the quantification of flow resistance it is desirable to upscale the analysis. The proper geometrical scale for the quantification of the turbulent flow variables is the mean inter-stem space. Double-averaging methods (time and space averaging, herein DAM) become a relevant conceptual tool to express the conservation equation describing spatially heterogeneous flows within a space domain the flow. The quality of the mean (double-averaged) values depends on the number and on the location of the space-sample points or profiles. No systematic and rational approaches have been dedicated to the impacts of the number and location of the sample points on the quality of the mean quantities. The objective of this work is to study the positioning of a limited set of samples so to describe the system in an optimal way. The placement of sampling points results from an optimization procedure seeking the empirical probability distribution of the timeaveraged longitudinal velocity, obtained with 8 samples, that best reproduces the complete distribution. The results of the optimization are shown to be robust and applicable to situations where flow characterization is performed with little detail.
Year: 2009