Journal of
Faculty of Civil Engineering

IX INTERNATIONAL CONFERENCE
CONTEMPORARY ACHIEVEMENTS IN
CIVIL ENGINEERING
BOOK OF ABSTRACTS , 2024.y., pp. 7-7

	DOI: 10.14415/CACE2024.03
	UDC: 532.51:519.6
	CC-BY-SA 4.0 license
	Author : Đorđević Dejana
	Summary:
	The double-averaging methodology (DAM) arose to respond to a need to provide a mathematically rigorous tool for describing spatially heterogeneous turbulent flows. Initial developments originate from micrometeorologists who revealed notable discrepancies between measured and simulated temperature and moisture fields above trees when using only Reynolds-averaged Navier-Stokes (RANS) equations with various turbulence model closures. The discrepancies were attributed to the spatial inhomogeneity of the flow field caused by vegetation. Thus, additional spatial averaging of RANS equations over horizontal planes sufficiently large to provide statistical averaging of all differences caused by an arbitrary distribution of plants and the influence of the biggest vortices responsible for the transfer of momentum was suggested. The advantages of using the DAM in open-channel hydraulics of gravel-bed rivers were recognised in the early 2000s when DAM was first applied and consequently improved. Open-channel vegetated flows are another example of spatially heterogene¬ous turbulent flows to which the DAM can be applied. The paper presents the results of the DoubleVeg project led by the author, in which a new set of equations was derived. After introducing the basic DAM concepts, the procedure of deriving Depth-Integrated Double-Averaged Navier-Stokes equations is presented. Consequently, the main challenges in solving these equations are discussed, and the results of initial testing of systems of homogeneous and non-homogeneous equations are shown.
	Keywords:
	SPATIALLY HETEROGENEOUS FLOWS, REPRESENTATIVE AVERAGING VOLUME , POROSITY, DOUBLE AVERAGING, DIDANS EQUATIONS, ADAPTED ROE’S METHOD