This title appears in the Scientific Report :
2014
Heterogeneous evaporation across a turbulent internal boundary layer
Heterogeneous evaporation across a turbulent internal boundary layer
In local evaporation from sufficiently uniform and large surfaces, horizontal advection close to the changesin surface condition is not significant. Under natural condition, this assumption is often invalid and horizontalinhomogeneity is important. When partially saturated air flows from a uniform d...
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Personal Name(s): | Shahraeeni, Ebrahim (Corresponding Author) |
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Vanderborght, Jan / Vereecken, Harry | |
Contributing Institute: |
Agrosphäre; IBG-3 |
Published in: | 2014 |
Imprint: |
2014
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Conference: | General Assembly 2014- European Geoscience Union, Vienna (Austria), 2014-04-27 - 2014-05-02 |
Document Type: |
Poster |
Research Program: |
Terrestrial Systems: From Observation to Prediction Modelling and Monitoring Terrestrial Systems: Methods and Technologies |
Publikationsportal JuSER |
In local evaporation from sufficiently uniform and large surfaces, horizontal advection close to the changesin surface condition is not significant. Under natural condition, this assumption is often invalid and horizontalinhomogeneity is important. When partially saturated air flows from a uniform dry land surface over a wet surface,all lower boundary conditions of transport equations change abruptly. Also surface humidity and roughness arelikely to be different from their upwind values. Due to these changes, the velocity profile and turbulence structureof the airflow must readjust. The vertical profiles are no longer in equilibrium and the horizontal gradients do notequal to zero. When there is more than one of these changes in the domain of interest, the interaction betweendifferent patches with a contrast in roughness, temperature or surface water content is also important.Rigorous experimental and numerical analysis of turbulent transfer of mass and momentum in the so-calledinternal boundary layer (the region affected by such step changes in surface condition) is the aim of this work.A combination of numerical simulations using in-house codes and commercial softwares and experimentalmeasurements in the environmental wind tunnel is performed. We are specifically interested in correct depictionof roughness, in a more accurate representation of the turbulent velocity profile and in a better description ofturbulent diffusion close to the interface. A series of simplifying assumptions in the classical representation of thisproblem are investigated and a sensitivity analysis is performed to identify the contribution of neglected terms. Weare also interested in the parameterization of the heat and mass exchange processes for the case with different wetpatches in a background of dry soil, which is of interest in several field scale applications. |