Active Control of Flow around Circular Cylinder by Means of Oscillating Thin Plate
Project/Area Number |
06650199
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Research Category |
Grant-in-Aid for General Scientific Research (C)
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Allocation Type | Single-year Grants |
Research Field |
Fluid engineering
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Research Institution | Yamanashi University |
Principal Investigator |
MIYATA Masafumi Yamanashi Univ., Faculty of Engrg, Professor, 工学部, 教授 (10023318)
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Project Period (FY) |
1994 – 1995
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Project Status |
Completed (Fiscal Year 1995)
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Budget Amount *help |
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1995: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1994: ¥1,600,000 (Direct Cost: ¥1,600,000)
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Keywords | Turbulent shear flow / Flow around circular cylinder / Flow control / Active control / Drag of circular cylinder / Strouhal number / Periodic disturbance / Disturbed flow / 振動薄板 |
Research Abstract |
Experimental investigation has been conducted on the possibility of an active control of the flow around a circular cylinder by means of an oscillating thin plate at Reynolds numbers of 1.0*10^4 and 2.0*10^4. The thin plate was placed near the separated shear layr at three streamwise positions ; CASE1, the trailing edge of the plate coincides with the cylinder center line, CASE2, center lines of the plate and cylinder coincide with each other and CASE3, the leading edge of the plate coinsides with the cylinder center line. The transverse distance of the plate from the cylinedr was changed from 0.5 to 5 times the boundary layr thickness just before the separation. Main results obtained are as follows. (1) The drag of the cylinder increases irrespetive of the plate distance for CASE1. (2) Drag reduction occurs when the plate is placed outside the boudary layr for CASE2. (3) The drag reduction of 10 to 20% is attained for CASE3 irrespective of the plate destance. (4) The drag reduction for CASE2 and 3 comes from the increase of back presure of the cylinder. (5) The effect of the plate oscillation about zero mean angle of attack is negligible for the frequency range investigated (40-200Hz) and the oscillating angle (1.0-7.6degs.). (6) It is possible to reduce the cylinder drag even for CASE1, if a narrower strip of thin plate is placed.
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Report
(3 results)
Research Products
(3 results)