1998 Fiscal Year Final Research Report Summary
STUDY ON THE IMPROVEMENT OF AIR CURTAIN PERFORMANCE BY THE MANIPULATION OF VORTICES
| Project/Area Number |
09650203
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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 | HOKKAIDO INSTITUTE OF TECHNOLOGY |
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Principal Investigator |
TOYODA Kuniaki HOKKAIDO INSTITUTE OF TECHNOLOGY, THE DEPARTMENT OF ENGNEERING, PROFESSOR, 工学部, 教授 (50048039)
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| Co-Investigator(Kenkyū-buntansha) |
KAWAI Hiroaki HOKKAIDO INSTITUTE OF TECHNOLOGY, THE DEPARTMENT OF ENGNEERING, ASSOCIATE PROFESSOR, 工学部, 助教授 (70118131)
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| Project Period (FY) |
1997 – 1998
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| Keywords | AIR CURTAIN / JET / VORTEX / FLOW CONTROL / THREE-DIMENSIONAL PERTURBATION |
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| Research Abstract |
(1) A heating box was built up as the experimental apparatus to measure the performance of air curtain. The size of the box is 1.5m×1.5m×1.5m, and an air curtain is installed at an opening door of the box. The air is issued from the top and sucked into the bottom. The ribbon heater is pasted on the floor, and the temperatures inside and outside of the box are measured by thermocouple. The data are recorded in a hybrid recorder and processed by a data processing computer. The performance of the box was confirmed to be good for the study of air curtain.
(2) The heat transfer through the air curtain perturbed by saw-shape roughness was measured and compared with that without the perturbation. The difference of the temperatures inside and outside of the box increased fifty percents, which results from the suppression of the large-scale vortices in the air curtain by the three-dimensional perturbation generated by saw-shape roughness.
(3) The effect of three-dimensional perturbation on jet diffusion was studied by the experiments of jets. The saw-shape roughness and soft fibers were attached at the jet exit to generate three-dimensional perturbations. The characteristics of diffusion were discussed by considering the measured velocity profiles. The result shows that the perturbations are very effective to suppress jet diffusion. From the result we suggest the suitable features of saw-shape roughness and soft fibers.
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