1998 Fiscal Year Final Research Report Summary
The Effects of Forest Canopy Models on Damping of Turbulent Energy in a Flow
| Project/Area Number |
09650200
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Fluid engineering
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| Research Institution | Miyazaki University |
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Principal Investigator |
HIRANO Kimitaka Miyazaki University, Department of Mechanical Systems Engineering, professor, 工学部, 教授 (40094081)
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| Project Period (FY) |
1997 – 1998
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| Keywords | plant canopy / wind tunnel testing / finite difference method / turbulent energy / leaf area index / effect of wind break |
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| Research Abstract |
This research is composed of three parts ; (1) the first is the experiments with the medium wind tunnel, (2) the second is that with the large wind tunnel, and (3) the third is the numerical simulation with the finite difference method and the crown-particle dynamics like the molecular dynamics.
(1) The canopy model in this testing has the leaf area index of 6.6. Distributions of streamwise velocity components in the downstream region of the model are measured with the CTA.Flows between individual tree models are different from flows downstream of trees. Flows downstream of the canopy models showed strong three-dimensional characteristics.
(2) This testing is experimented with the large wind tunnel constructed in Miyazaki University on January 1998. The canopy model has the leaf area index of 9.0. Distributions of the time-averaged velocity and intensity of turbulence in the shear-layer above the canopy are changed with the different pitch from arrangement of individual tree models.
(3) Flow fields are simulated with the FDM-SMAC method. The crowns of canopy are approximated with a lot of particles that are connected with neighbor particles by spring and damper. The motion of air flows and the motion of particles in the crown are linked in the time-marching. Flow fields around the canopies of various sparse and dense crowns are calculated numerically. These results are good agreement with the results of the experiments with the wind tunnel testing.
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