Determination of 3-D Velocity and Vorticity Vectors in Turbulent Flows by Multi-Hotwire Anemometry

Lemonis, G.; Dracos, Themistocles

doi:10.1007/978-94-015-8727-3_1

Cited by 3 publications

(4 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Lemonis [39] and Lemonis and Dracos [37], designed and constructed an improved version of the five-array probe developed by Kit et al [34] and developed a novel calibration and data reduction method based on look-up tables. Their work is the starting point of the techniques used in the herein presented work and will be discussed extensively in the following, along with the work of Cavo et al [9] who shared the measuring equipment of the present work studying a rectangular jet.…”

Section: Multi Sensor Hwa For Vorticity Measurementsmentioning

confidence: 99%

“…The uniqueness domain of four wire arrays has been investigated by several investigators (Rosemann [58], Pailhas and Cousteix [54], Lemonis and Dracos [37]). For 45 • -slanted wires they conclude that uniqueness is guaranteed for velocity vector angles of at least 30 • to the longitudinal direction.…”

Section: The Experiments Setupmentioning

confidence: 99%

“…The four different sub-array solutions are used for the estimation of the velocity vector at the centroid of each four wire array. The technique has been described extensively and tested by Lemonis [39] and Lemonis and Dracos [37,38]). …”

Section: The Experiments Setupmentioning

confidence: 99%

See 2 more Smart Citations

Multisensor Hot Wire Vorticity Probe Measurements of the Formation Field of Two Corotating Vortices

Romeos

Lemonis

Papailiou

2009

Flow Turbulence Combust

View full text Add to dashboard Cite

Experimental evidence is reported, regarding the formation of a pair of co-rotating tip vortices by a split wing configuration, consisting of two half wings at equal and opposite angles of attack. Simultaneous measurements of the threedimensional vector fields of velocity and vorticity were conducted on a cross plane at a downstream distance corresponding to 0.3 cord lengths (near wake), using an in-house constructed 12-sensor hot wire anemometry vorticity probe. The probe consists of three closely separated orthogonal 4-wire velocity sensor arrays, measuring simultaneously the three-dimensional velocity vector at three closely spaced locations on a cross plane of the flow filed. This configuration makes possible the estimation of spatial velocity derivatives by means of a forward difference scheme of first order accuracy. Velocity measurements obtained with an X-wire are also presented for comparison. In this near wake location, the flow field is dictated by the pressure distribution established by the flow around the wings, mobilizing large masses of air and leading to the roll up of fluid sheets. Fluid streams penetrating between the wings collide, creating on the cross plane flow a stagnation point and an "impermeable" line joining the two vortex centres. Along this line fluid is directed towards the two vortices, expanding their cores and increasing their separation distance. This feeding process generates a dipole of opposite sign streamwise mean vorticity within each vortex. The rotational flow within the vortices obligates an adverse streamwise pressure gradient leading to a significant streamwise velocity deficit characterizing the vortices. The turbulent flow field is the result of temporal changes in the intensity of the vortex formation and changes in the position of the cores (wandering).

show abstract

Section: Multi Sensor Hwa For Vorticity Measurementsmentioning

confidence: 99%

Section: The Experiments Setupmentioning

confidence: 99%

See 1 more Smart Citation

Multisensor Hot Wire Vorticity Probe Measurements of the Formation Field of Two Corotating Vortices

Romeos

Lemonis

Papailiou

2009

Flow Turbulence Combust

View full text Add to dashboard Cite

show abstract

“…Kovasznay [1], Corrsin and Kistler [2], Foss [3], Wallace and Vukoslavcević [4], Wallace [5], Foss and Wallace [6]; see also the review by Wallace and Foss [7]). Most of the previous efforts have focused only on one fluctuating vorticity component although attempts to measure three components simultaneously include those of Wassman and Wallace [8], Vukoslavcević et al [9], Balint et al [10,11], Tsinober et al [12], Wallace et al [13], Marasli et al [14], Honkan and Andreopoulos [15] and Lemonis [16]. These measurements involve at least nine hot wires and relatively tedious calibration procedures.…”

Section: Introductionmentioning

confidence: 99%

Spatial resolution of a 4-X-wire vorticity probe

Zhu

Antonia

1996

Meas. Sci. Technol.

View full text Add to dashboard Cite

The spatial resolution of a vorticity probe consisting of four X-wires is studied analytically to evaluate the effects of the separation between different X-wires, the separation between the sensors in each X-wire and the effective angles of the inclined sensors on the statistics of the vorticity fluctuation and its components. Correction ratios for the variance of vorticity and its components as well as their spectra are computed for the case of local isotropy. These ratios are useful for estimating measurement errors or correcting the data for the effect of spatial resolution.

show abstract