Studies of forced-convection heat and mass transfer of fluttering realistic leaf models
- Cite this article as:
- Schuepp, P.H. Boundary-Layer Meteorol (1972) 2: 263. doi:10.1007/BF02184768
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The forced-convection mass transfer - and by analogy, heat transfer - of various realistic leaf models at Reynolds numbers 2 x 103<Re<4 x 104 was studied with an electrochemical method. The results are compared with similar measurements on plates and with transfer coefficients calculated from the laminar boundary-layer theory. In this way the validity of the commonly-used analytical expressions which represent the leaf by a rigid plate and neglect the effects of leaf curvature, fluttering, surface roughness and fluid turbulence, can be tested.
The measurements show that for fluttering single leaves, the convective mass-transfer coefficients must be expected to be higher by a factor of 1.4 ± 0.1 than the ones calculated for rigid plates of equal size and shape. For a leaf in a crop, the increase might be as high as a factor of 2. The high transfer coefficients measured for elements of cedar foliage are also discussed.