Experiments on oscillating flow at the abrupt transition between a two-dimensional channel and essentially infinite space are presented. It is shown that phenomena associated with the transition are functions of three independent dimensionless parameters including the dimensionless radius rounding the edge of the end of the channel. The effect of each of these three parameters on the time-averaged pressure difference across the transition and the acoustic power dissipation is explored by holding two parameters fixed while varying the third. Evidence is presented that the losses due to oscillatory flow in this geometry are smaller than would be expected from commonly accepted values for steady flow in similar geometry.
REFERENCES
1.
G. W.
Swift
, D. L.
Gardner
, and S.
Backhaus
, “Acoustic recovery of lost power in pulse tube refrigerators
,” J. Acoust. Soc. Am.
105
, 711
–724
(1999
).2.
S.
Backhaus
and G. W.
Swift
, “A thermoacoustic-Stirling heat engine: Detailed study
,” J. Acoust. Soc. Am.
107
, 3148
–3166
(2000
).3.
E. Fried and I. E. Idelchik, Flow Resistance (Hemisphere, New York, 1989).
4.
R. S.
Wakeland
and R. M.
Keolian
, “Influence of velocity profile nonuniformity on minor losses for flow exiting thermoacoustic heat exchangers
,” J. Acoust. Soc. Am.
112
, 1249
–1252
(2002
).5.
P. J. Morris, S. Boluriaan, and C. M. Shieh, “Computational thermoacoustic simulation of minor losses through a sudden contraction and expansion,” 7th AIAA/CEAS Aeroacoustics Conference, 2001, paper 2001-2272.
6.
A.
Petculescu
and L.
Wilen
, “Lumped-element technique for the measurement of complex density
,” J. Acoust. Soc. Am.
110
, 1950
–1957
(2001
).7.
L. Wilen, A. Petculescu, and G. Petculescu, “Impedance measurements of stacks, regenerators and jet pumps,” Proceedings of the 17th International Congress on Acoustics, Rome, Italy, 2001.
8.
J. K. Vennard, “One-dimensional flow,” in Handbook of Fluid Dynamics, edited by V. L. Streeter (McGraw-Hill, New York, 1961).
9.
B. R. Munson, D. F. Young, and T. H. Okiishi, Fundamentals of Fluid Mechanics, 2nd ed. (Wiley, New York, 1994), Fig. 8.28.
10.
A. G. Fredrickson and R. B. Bird, “Transport phenomena in multicomponent systems,” in Handbook of Fluid Dynamics, edited by V. L. Streeter (McGraw-Hill, New York, 1961), Eq. 6.208.
11.
B. L.
Smith
and G. W.
Swift
, “Measuring second-order time-averaged pressure
,” J. Acoust. Soc. Am.
110
, 717
–723
(2001
).12.
G. S. Settles, Schlieren and Shadowgraph Techniques (Springer, New York, 2001), Fig. 3.8.
13.
M.
Ohmi
, M.
Iguchi
, K.
Kakehashi
, and M.
Tetsuya
, “Transition to turbulence and velocity distribution in an oscillating pipe flow
,” Bull. JSME
25
, 365
–371
(1982
).14.
A. K. M. F.
Hussain
and W. C.
Reynolds
, “Measurements in fully developed turbulent channel flow
,” J. Fluids Eng.
97
, 568
–580
(1975
).15.
M.
Gharib
, E.
Rambod
, and K.
Shariff
, “A universal time scale for vortex ring formation
,” J. Fluid Mech.
360
, 121
–140
(1998
).16.
U.
Ingard
and S.
Labate
, “Acoustic circulation effects and the nonlinear impedance of orifices
,” J. Acoust. Soc. Am.
22
, 211
–218
(1950
).17.
B. L. Smith and G. W. Swift, “Synthetic jets at large Reynolds number and comparison to continuous jets,” 31st AIAA Fluid Dynamics Conference, 2001, paper 2001-3030.
18.
G. W. Swift, Thermoacoustics: A Unifying Perspective for Some Engines and Refrigerators (Acoustical Society of America, Publications, Sewickley, PA, 2002).
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