Zero-plane displacement: Difference between revisions

Latest revision as of 04:32, 31 March 2024

A height scale in turbulent flow over tall roughness elements associated with the average level of action of momentum transfer between the flow and the roughness elements.

In neutral stability the logarithmic wind profile becomes a straight line only if the vertical axis is shifted by the zero-plane displacement length. Several formulas exist to relate this height scale as a function of the roughness element geometry (for example, spacing and silhouette area). Tabulated values for various surface types are published in most micrometeorological texts, for example, Oke (1987).
See surface roughness.

(Also called displacement distance, displacement thickness.) In a viscous homogeneous fluid, the depth of a boundary layer of shearing flow over a flat plate.
Oke, T. R. 1987. Boundary Layer Climates. 2d ed., . 435 pp.

@@ Line 1: / Line 1: @@
+{{Term
+|Display title=zero-plane displacement
-{{TermHeader}}
+|Definitions={{Definition
-{{TermSearch}}
+|Num=1
+|Meaning=#A height scale in [[turbulent flow]] over tall roughness elements associated  with the average level of action of [[momentum transfer]] between the flow and the roughness  elements.
-<div class="termentry">
+|Explanation=In [[neutral stability]] the logarithmic [[wind profile]] becomes a straight line only if the vertical  axis is shifted by the zero-plane displacement length. Several formulas exist to relate this height  scale as a function of the roughness element geometry (for example, spacing and silhouette area).  Tabulated values for various surface types are published in most micrometeorological texts, for  example, Oke (1987). <br/>''See'' [[surface roughness]].<br/>
-  <div class="term">
+#(''Also called'' displacement distance, displacement thickness.) In a viscous [[homogeneous fluid]],  the depth of a [[boundary layer]] of shearing flow over a flat plate.<br/> Oke, T. R. 1987. Boundary Layer Climates. 2d ed., . 435 pp.
-== zero-plane displacement ==
+}}
-  </div>
+}}
-#<div class="definition"><div class="short_definition">A height scale in [[turbulent flow]] over tall roughness elements associated  with the average level of action of [[momentum transfer]] between the flow and the roughness  elements.</div><br/> <div class="paragraph">In [[neutral stability]] the logarithmic [[wind profile]] becomes a straight line only if the vertical  axis is shifted by the zero-plane displacement length. Several formulas exist to relate this height  scale as a function of the roughness element geometry (for example, spacing and silhouette area).  Tabulated values for various surface types are published in most micrometeorological texts, for  example, Oke (1987). <br/>''See'' [[surface roughness]].</div><br/> </div>
-#<div class="definition"><div class="short_definition">(''Also called'' displacement distance, displacement thickness.) In a viscous [[homogeneous fluid]],  the depth of a [[boundary layer]] of shearing flow over a flat plate.</div><br/> </div><div class="reference">Oke, T. R. 1987. Boundary Layer Climates. 2d ed., . 435 pp. </div><br/>
-</div>
-{{TermIndex}}
-{{TermFooter}}
-[[Category:Terms_Z]]