&lt;title&gt;LDA measurements on swirling flows in tubes&lt;/title&gt;

Kok, Jacobus B.W.; Rosendal, F.J.J.; Brouwers, Jjh Bert

doi:10.1117/12.150571

Cited by 9 publications

(3 citation statements)

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“…Recent experimental investigations of fluid mechanics in swirl chambers with single-phase flow, wall injection, and no heat transfer include Kumar and Conover (1993), Dong and Lilly (1993), Bruun et al (1993), Fitouri et al (1995), and Chang and Dhir (1994). Rotating vanes, blades, propellers, or honeycombs are used near tube entrances by Sampers et al (1992) and Li and Tomita (1994) and Kok et al (1993) to induce swirl in adiabatic flows. Surveys of swirl flow investigations are presented by Gambil and Bundy (1962), Bergles (1969), Razgaitis and Holman (1976), Papadopoulos et al (1991), and Ligrani et al (1997).…”

Section: Introductionmentioning

confidence: 99%

Heat Transfer and Flow Phenomena in a Swirl Chamber Simulating Turbine Blade Internal Cooling

Hedlund

Ligrani

Moon³

et al. 1998

Volume 4: Heat Transfer; Electric Power; Industrial and Cogeneration

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Heat transfer and fluid mechanics results are given for a swirl chamber whose geometry models an internal passage used to cool the leading edge of a turbine blade. The Reynolds numbers investigated, based on inlet duct characteristics, include values which are the same as in the application (18000–19400). The ratio of absolute air temperature between the inlet and wall of the swirl chamber ranges from 0.62 to 0.86 for the heat transfer measurements. Spatial variations of surface Nusselt numbers along swirl chamber surfaces are measured using infrared thermography in conjunction with thermocouples, energy balances, digital image processing, and in situ calibration procedures. The structure and streamwise development of arrays of Görtler vortex pairs, which develop along concave surfaces, are apparent from flow visualizations. Overall swirl chamber structure is also described from time-averaged surveys of the circumferential component of velocity, total pressure, static pressure, and the circumferential component of vorticity. Important variations of surface Nusselt numbers and time-averaged flow characteristics are present due to arrays of Görtler vortex pairs, especially near each of the two inlets, where Nusselt numbers are highest. Nusselt numbers then decrease and become more spatially uniform along the interior surface of the chamber as the flows advect away from each inlet.

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Section: Introductionmentioning

confidence: 99%

Heat Transfer and Flow Phenomena in a Swirl Chamber Simulating Turbine Blade Internal Cooling

Hedlund

Ligrani

Moon³

et al. 1998

Volume 4: Heat Transfer; Electric Power; Industrial and Cogeneration

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“…An experiment was conducted to measure the velocity field of the tangentially injected swirling flow inside the concentric tubes of different lengths, to investigate the effects of some structural parameters, and to enable a comparison to be made with the results obtained by the numerical simulation. Various studies have been reported in the literature on measuring the flow field and investigating the characteristics of the swirling flow using experimental methods, including single-point measurements such as Pitot tube, [27][28][29] hot-wire anemometry (HWA), [30][31][32] laser Doppler anemometry (LDA), [33][34][35] and flow visualization. [36][37][38][39][40] As an advanced nonintrusive method that can measure the instantaneous velocity fields, PIV has also been used in the measurement of a swirling flow field.…”

Section: Methodsmentioning

confidence: 99%

Effects of structural parameters on the tangentially injected swirling flow in concentric tubes with different lengths as a model of the vortex spinning nozzle

Sun

Pei

2015

Textile Research Journal

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The tangentially injected swirling tube flow has broad applications in various engineering fields. In the textile industry, the vortex spinning technology, which produces short-staple yarns by means of a tangentially injected swirling airflow, is of great prospect in view of its spinning speed and yarn structure. In this paper, the vortex spinning nozzle is abstracted into a model of concentric tubes of different lengths with tangential injectors. A computational fluid dynamics model is presented to study the effects of some structural parameters on the swirling flow generated in this tube system. The particle image velocimetry (PIV) technique is adopted to measure the flow field. Due to the difficulty in duplicating the Mach number, Reynolds numbers are matched between the tube model and prototype in the PIV experiment. Despite the discrepancy between the velocity values provided by the numerical simulation and experiment due to the compressibility effects not being reproduced in the PIV measurement, a comparative analysis concludes that qualitatively matched results on the flow pattern and effects of the structural parameters are obtained by the numerical simulation and PIV measurement.

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“…Two other studies (Sampers at at, 1992;Li and Tomita, 1994) employ rotating vanes, blades, or propellers only near tube entrances to induce swirl in adiabatic flows. Kok at at (1993) study flow in a tube where swirl is induced by a rotating honeycomb which produces a velocity profile close to that of an ideal forced vortex. Recent numerical predictions of confined, single-phase, swirling flows in pipes and ducts without heat transfer are presented by Hirai and Takagi (1991), Dong and Lilly (1993), Li and Tomita (1994), Beran (1994), Yu and Kitoh (1994), Reader-Harris (1994), andSharif andWong (1995).…”

Section: Introductionmentioning

confidence: 99%

Flow Phenomena in Swirl Chambers

Ligrani

Hedlund

Thambu

et al. 1997

Volume 3: Heat Transfer; Electric Power; Industrial and Cogeneration

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Results are presented from two different swirl chambers. One of the practical directions for this study is simulation of cooling passages located near the leading edges of turbine blades where screw-shaped, swirling flows are generated to enhance heat transfer. Flow visualization results are given at Reynolds numbers ranging from 900 to 19,000, along with example surveys of mean velocity components, static pressure, and total pressure. Arrays of Görtler vortices are evident along the concave surface of the chamber, in addition to a second array in the shear layer located a short distance from the wall. As Reynolds number increases, vortex pair unsteadiness increases, the number of vortex pairs across the span increases, and interactions between adjacent vortex pairs becomes more intense, chaotic, and frequent. With axial flow components in the swirl chambers, skewness, unsteadiness, and three-dimensionality of the larger Görtler vortices become even more pronounced as they continuously intermingle with smaller Görtler vortex pairs.

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<title>LDA measurements on swirling flows in tubes</title>

Cited by 9 publications

References 0 publications

Heat Transfer and Flow Phenomena in a Swirl Chamber Simulating Turbine Blade Internal Cooling

Heat Transfer and Flow Phenomena in a Swirl Chamber Simulating Turbine Blade Internal Cooling

Effects of structural parameters on the tangentially injected swirling flow in concentric tubes with different lengths as a model of the vortex spinning nozzle

Flow Phenomena in Swirl Chambers

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