Evaluation of the inertial dissipation method within boundary layers using numerical simulations

Jabbari, Aidin; Boegman, Leon; Piomelli, Ugo

doi:10.1002/2015gl063147

Cited by 12 publications

(15 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…(c) Ratio between vertical and along‐stream Kolmogorov constants determined in our study in comparison with the values of Jabbari et al . []. The vertical solid line denotes the value of 4/3 as generally used in the IDM.…”

Section: Boundary Layer Characterization By Stepwise Profilingcontrasting

confidence: 43%

“…We found that the use of the inertial dissipation method using the generally accepted Kolmogorov constants for the determination of ε under these conditions is not valid any more. Our study provides evidence that the constants determined by numerical modeling [ Jabbari et al ., ] are more appropriate in the close vicinity of the SWI in natural systems. In addition, we were able to observe the viscous boundary layer and to find indications of a double logarithmic layer in the very close vicinity of the SWI‐ an achievement which would not have been possible with standard ADVs with a spatial resolution of about 1.5 cm.…”

Section: Discussionmentioning

confidence: 99%

“… Analysis of the inertial dissipation method based on the Kolmogorov constants for anisotropic flow (IDM) in comparison with the numerical simulation study of Jabbari et al . [] (AJM). (a) Dissipation calculated using vertical velocity spectra and the constants of IDM and AJM.…”

Section: Boundary Layer Characterization By Stepwise Profilingmentioning

confidence: 99%

“…The profile of

α_{w} / α_{u}

calculated using the Kolmogorov constants determined by Jabbari et al . [] are in excellent agreement with our measurements (Figure c). This suggests that the Kolmogorov constants provided by their modeling study are more appropriate for our near SWI study (in the following we will refer to the use of the constants to estimate ε determined by Jabbari et al .…”

Section: Boundary Layer Characterization By Stepwise Profilingmentioning

confidence: 99%

See 3 more Smart Citations

High‐resolution flow characterization close to the sediment‐water interface in a run of the river reservoir

Brand

Noß

2017

Water Resources Research

View full text Add to dashboard Cite

A bistatic high‐resolution acoustic profiler was used in order to characterize the lowermost boundary layer of a run of the river reservoir. The profiler allows determining the statistics of the three‐dimensional flow field at a single point (sweet spot) as well as the measurement of the time averaged flow velocity profiles at 1 mm resolution around the sweet spot. Therefore, in addition to the flow statistics provided by single point acoustic Doppler profilers, mixing coefficients as well as production of turbulent kinetic energy can be calculated using a single device. Fitting of semiempirical relations to observed cospectra allowed eliminating artifacts as they result from coordinate system rotation during calculation of Reynolds stress profiles at millimeter resolution. While most parameters showed characteristics of a constant stress layer, length scales indicated anisotropy of the turbulent flow. Under these anisotropic near wall conditions, we found that the use of the commonly accepted Kolmogorov constants for the determination of dissipation rates using the inertial dissipation method is not valid any more. Instead, these constants vary with distance from the sediment water interface. We provide evidence that coefficients determined by numerical simulations are the appropriate choice also in field applications. In addition we resolved the viscous boundary layer close to the sediment‐water interface in high resolution (1 mm) profiles and identified a double logarithmic layer above 1.5 cm at one location. The discrepancy of the scales as well as the double logarithmic layer suggests the existence of roughness elements upstream of the measurement sites.

show abstract

Section: Boundary Layer Characterization By Stepwise Profilingcontrasting

confidence: 43%

Section: Discussionmentioning

confidence: 99%

Section: Boundary Layer Characterization By Stepwise Profilingmentioning

confidence: 99%

“…The profile of

α_{w} / α_{u}

Section: Boundary Layer Characterization By Stepwise Profilingmentioning

confidence: 99%

See 2 more Smart Citations

High‐resolution flow characterization close to the sediment‐water interface in a run of the river reservoir

Brand

Noß

2017

Water Resources Research

View full text Add to dashboard Cite

show abstract

“…In this method, the correlation function between two points with the vertical separation distance r (i.e., 3 cm bin size)

SF ((), z, r) = \overset{{((), u_{b}^{'} ((), z) - u_{b}^{'} ((), z + r))}^{2}}{true}

is related to the dissipation by SF( z , r ) = ∝ ε 2/3 r 2/3 within the inertial subrange, where ∝ is the Kolmogorov (2/3) constant, and

u_{b}^{'}

is the in‐beam fluctuating velocity obtained from Reynolds averaging each burst (the over‐bar denotes the time average). To account for the anisotropy from the bed shear stress (Jabbari et al ), we applied the anisotropy adjusted constants (Jabbari et al ), where ∝ is a function of the normalized distance from the bed z + = zu * / ν , where u * is the shear velocity. To compute u * , the profiles of the mean horizontal velocity

u_{m} = \sqrt{(u^{2} + v^{2})}

were fit to the logarithmic law‐of‐the‐wall over the constant stress layer by the least‐square‐fitting method (e.g., Jabbari ; Valipour et al ).…”

Section: Methodsmentioning

confidence: 99%

Episodic hypoxia in the western basin of Lake Erie

Jabbari

Ackerman

Boegman

et al. 2019

Limnology & Oceanography

Self Cite

View full text Add to dashboard Cite

Hypoxic conditions continue to be an environmental concern in lakes, including those with shallow and well‐mixed basins, such as the western basin of Lake Erie, in which hypoxia is not anticipated. We investigated the dynamics and causes of hypoxia using field measurements at two locations in the western basin during the late summer of 2017. Two hypoxic events (dissolved oxygen [DO] concentrations < 2 mg L−1) were recorded that were caused by upwelling of hypolimnetic water from the central basin of the lake following winds from the south and southwest. In this case, instantaneous stratification occurred when cool central basin water (i.e., 15.7°C) intruded as a 2.5‐m‐thick layer above the bottom under the warm western basin waters (i.e., 23.9°C). A third hypoxic event, which was associated with more typical thermal stratification from atmospheric warming, occurred during a calm and warm period near the end of the deployment. In this case, we observed a continuous decline in hypolimnetic DO from ≈ 8 to < 5 mg L−1, which likely declined to < 2 mg L−1 in 14 d using a one‐dimensional model. Interbasin exchange flows generated instantaneous hypoxia multiple times within a year and were the dominate cause (63% of 11 cases) of hypoxia identified during August fishing trawls in the study area over the past 30 yr. Results of this work should help with the prediction and understanding of hypoxia in lakes with multiple basins, which will be informative for water quality and fisheries management.

show abstract

Evaluation of the structure function method to compute turbulent dissipation within boundary layers using numerical simulations

2016

Self Cite

View full text Add to dashboard Cite

Well-resolved numerical simulations of turbulent open channel flows are analyzed to evaluate the accuracy of the 2nd order structure function method (SFM) in estimating the rate of dissipation of turbulent kinetic energy within boundary layers. The objective is to assess the variation in the 2/3 Kolmogorov constants due to flow anisotropy with distance from the wall. Comparison of the dissipation calculated directly from the numerical data, with that from the SFM shows that usage of the canonical constants, based on the assumption of local isotropy, can result in considerable error (>50%) in the prediction of dissipation when using the vertical or spanwise velocity components. From the numerically calculated dissipation, optimal Kolmogorov 2/3 constants were obtained and empirical relations, which account for near-wall effects, were proposed. Usage of the optimal constants will improve estimation of the dissipation rate when the SFM is applied to compute dissipation in geophysical boundary-layer flows.

show abstract

Evaluation of the inertial dissipation method within boundary layers using numerical simulations

Cited by 12 publications

References 43 publications

High‐resolution flow characterization close to the sediment‐water interface in a run of the river reservoir

High‐resolution flow characterization close to the sediment‐water interface in a run of the river reservoir

Episodic hypoxia in the western basin of Lake Erie

Evaluation of the structure function method to compute turbulent dissipation within boundary layers using numerical simulations

Contact Info

Product

Resources

About