A constant-voltage anemometer is subject to nonlinear effects when the operating hot wire is exposed to large velocity fluctuations in the incident flow. This results in the generation of undesirable higher harmonics, just as in the two classic systems, constant-current and constant-temperature anemometers, for which no attempts are normally made to correct the nonlinearities. The present investigation shows that these undesirable higher harmonics can be suppressed in the case of a constant-voltage anemometer. A new approach to process experimental data is proposed. It is based on three explicit equations established and solved with all terms included, i.e., without linearization. These are (1) the first-order differential equation that describes the electronic circuit of a constant-voltage anemometer—this equation permits to deduce the instantaneous resistance of the hot wire from the output voltage of the anemometer; (2) the first-order differential equation that expresses the thermal lag behavior of the hot wire when used in a constant-voltage mode—this equation permits to restore the instantaneous resistance that an ideal wire would have without thermal inertia in the same flow conditions; and (3) the algebraic relation that expresses the heat-transfer law of an ideal wire, according to King’s law, a look-up table, or a polynomial fit—this relation permits to deduce the instantaneous flow velocity from the instantaneous resistance of the ideal wire. The proposed method is easily implemented on a personal computer and permits odd turbulence moments, such as skewness factors, to be obtained satisfactorily.

1.
S.
Corrsin
, in
Handbuch der Physik
, edited by
S.
Flugge
(
Springer
,
Berlin
,
1963
), Vol.
VIII/2
, pp.
524
590
.
2.
G.
Comte-Bellot
and
J. P.
Schon
,
Int. J. Heat Mass Transfer
12
,
1661
(
1969
).
3.
P.
Freymuth
,
Rev. Sci. Instrum.
40
,
258
(
1969
).
5.
H. J.
Hussein
,
S. P.
Capp
, and
W. K.
George
,
J. Fluid Mech.
258
,
31
(
1994
).
6.
H. H.
Bruun
,
Hot Wire Anemometry
(
Oxford Scientific
,
UK
,
1995
).
7.
P.
Ligęza
,
Rev. Sci. Instrum.
78
,
075104
(
2007
).
8.
G. R.
Sarma
,
Rev. Sci. Instrum.
69
,
2385
(
1998
).
9.
G.
Comte-Bellot
, in
Handbook of Fluid Dynamics
, edited by
R. W.
Johnson
(
CRC
,
Boca Raton, FL
,
1998
), Chap. 34.
10.
G.
Comte-Bellot
, in
Handbook of Experimental Fluid Mechanics
, edited by
C.
Tropea
,
A. L.
Yarin
, and
J. F.
Foss
(
Springer
,
Berlin
,
2007
), pp.
229
283
.
11.
G.
Comte-Bellot
,
J.
Weiss
, and
J. C.
Béra
,
58th Annual Meeting of the Division of Fluid Dynamics
, Chicago, 20–22 November
2005
(unpublished), p.
189
.
12.
G. R.
Sarma
,
G.
Comte-Bellot
, and
Th. M.
Faure
,
Rev. Sci. Instrum.
69
,
3223
(
1998
).
13.
G.
Comte-Bellot
and
G. R.
Sarma
,
AIAA J.
39
,
261
(
2001
).
14.
J. D.
Norris
and
N.
Chokani
,
AIAA J.
41
,
1619
(
2003
).
15.
T. R.
Moes
,
G. R.
Sarma
, and
S. M.
Mangalam
, Flight demonstration of a shock location sensor using constant voltage hot-film anemometry, NASA Technical Memorandum 4806,
1997
.
16.
G.
Comte-Bellot
,
J.
Weiss
, and
J. C.
Béra
,
Rev. Sci. Instrum.
75
,
2075
(
2004
).
17.
G. R.
Sarma
and
R. W.
Lankes
,
Rev. Sci. Instrum.
70
,
2384
(
1999
).
18.
L. S. G.
Kovasznay
,
J. Aeronaut. Sci.
20
,
657
(
1953
).
19.
M. V.
Morkovin
, Fluctuations and hot-wire anemometry in compressible flows, AGARdograph 24,
1956
.
20.
J.
Gaviglio
,
Int. J. Heat Mass Transfer
30
,
911
(
1987
).
21.
G. R.
Sarma
and
G.
Comte-Bellot
,
Rev. Sci. Instrum.
73
,
1313
(
2002
).
22.
C.
Bogey
and
C.
Bailly
,
Phys. Fluids
18
,
065101
(
2006
).
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