TY - JOUR

T1 - Effect of the water depth on oscillatory flows over a flat plate: from the intermittent towards the fully turbulent regime

AU - Kaptein, S.J.

AU - Duran Matute, M.

AU - Roman, Federico

AU - Armenio, V.

AU - Clercx, H.J.H.

PY - 2019/10/1

Y1 - 2019/10/1

N2 - We performed high-resolution numerical simulations of a turbulent flow driven by an oscillating uniform pressure gradient. The purpose was to investigate the influence of a reduced water depth h on the structure and dynamics of the turbulent boundary layer and the transition towards a fully turbulent flow. The study is motivated by applications of oscillatory flows, such as tides, in which h is of the same order of magnitude as the thickness of the turbulent boundary layer δ. It was found that, if h∼ δ, the turbulent flow is characterized by (1) an increase of the magnitude of the surface velocity, (2) an increase in the magnitude of the wall shear stress and (3) a phase lead of the velocity profiles, all with respect to the reference case for which h≫ δ. These results are in agreement with analytical solutions for a laminar oscillatory flow. Nevertheless, if the value of the Reynolds number is too small and h∼ δ, the flow relaminarizes.

AB - We performed high-resolution numerical simulations of a turbulent flow driven by an oscillating uniform pressure gradient. The purpose was to investigate the influence of a reduced water depth h on the structure and dynamics of the turbulent boundary layer and the transition towards a fully turbulent flow. The study is motivated by applications of oscillatory flows, such as tides, in which h is of the same order of magnitude as the thickness of the turbulent boundary layer δ. It was found that, if h∼ δ, the turbulent flow is characterized by (1) an increase of the magnitude of the surface velocity, (2) an increase in the magnitude of the wall shear stress and (3) a phase lead of the velocity profiles, all with respect to the reference case for which h≫ δ. These results are in agreement with analytical solutions for a laminar oscillatory flow. Nevertheless, if the value of the Reynolds number is too small and h∼ δ, the flow relaminarizes.

KW - Large eddy simulation

KW - Oscillatory flow

KW - Shallow flow

KW - Turbulence

UR - http://www.scopus.com/inward/record.url?scp=85062033705&partnerID=8YFLogxK

U2 - 10.1007/s10652-019-09671-3

DO - 10.1007/s10652-019-09671-3

M3 - Article

VL - 19

SP - 1167

EP - 1184

JO - Environmental Fluid Mechanics

JF - Environmental Fluid Mechanics

SN - 1567-7419

IS - 5

ER -