Simultaneous measurements of liquid velocity and tracer concentration in a continuous flow stirred tank

Paglianti, Alessandro; Montante, Giuseppina Maria Rosa

doi:10.1016/j.ces.2020.115495

Cited by 15 publications

(6 citation statements)

References 22 publications

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“…To demonstrate the swirl rate effect on the turbulent Schmidt number, the same equation was used for the flows with swirl and for the central pilot jet in the gas turbine combustor. However, it should be noted that other viscosity or diffusivity components can be used (e.g., for the rotating flows in steering mixers [18,19].)…”

Section: Nonswirling Jetmentioning

confidence: 99%

See 1 more Smart Citation

Testing Basic Gradient Turbulent Transport Models for Swirl Burners Using PIV and PLIF

Savitskii

Lobasov

Sharaborin

et al. 2021

Fluids

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The present paper reports on the combined stereoscopic particle image velocimetry (PIV) and planar laser induced fluorescence (PLIF) measurements of turbulent transport for model swirl burners without combustion. Two flow types were considered, namely the mixing of a free jet with surrounding air for different swirl rates of the jet (Re = 5 × 103) and the mixing of a pilot jet (Re = 2 × 104) with a high-swirl co-flow of a generic gas turbine burner (Re = 3 × 104). The measured spatial distributions of the turbulent Reynolds stresses and fluxes were compared with their predictions by gradient turbulent transport models. The local values of the turbulent viscosity and turbulent diffusivity coefficients were evaluated based on Boussinesq’s and gradient diffusion hypotheses. The studied flows with high swirl were characterized by a vortex core breakdown and intensive coherent flow fluctuations associated with large-scale vortex structures. Therefore, the contribution of the coherent flow fluctuations to the turbulent transport was evaluated based on proper orthogonal decomposition (POD). The turbulent viscosity and diffusion coefficients were also evaluated for the stochastic (residual) component of the velocity fluctuations. The high-swirl flows with vortex breakdown for the free jet and for the combustion chamber were characterized by intensive turbulent fluctuations, which contributed substantially to the local turbulent transport of mass and momentum. Moreover, the high-swirl flows were characterized by counter-gradient transport for one Reynolds shear stress component near the jet axis and in the outer region of the mixing layer.

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Section: Nonswirling Jetmentioning

confidence: 99%

“…Paglianti and Montante [18] studied mixing in a continuous flow stirred tank using the PIV and PLIF methods simultaneously. The authors evaluated the turbulent viscosity and diffusivity coefficients with the corresponding turbulent Schmidt number based on gradient diffusion and Boussinesq's hypotheses, respectively.…”

Section: Introductionmentioning

confidence: 99%

Testing Basic Gradient Turbulent Transport Models for Swirl Burners Using PIV and PLIF

Savitskii

Lobasov

Sharaborin

et al. 2021

Fluids

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“…A number of studies have focused on in-line flow viscosity measurement by a combination of ultrasonic velocity profiling (UPV) with a new non-contact ultrasonic transducer and pressure drop (PD) method [3]. This work [4] is the first to apply two methods in parallel: planar laser-induced fluorescence (PLIF) and particle image velocity (PIV) to measure the viscosity of moving fluid in a reservoir. In the aerohydrodynamic method [5], the authors propose to apply a pulsating air jet to the liquid surface and measure the viscosity by analyzing the parameters of the waves generated on the surface.…”

Section: Introductionmentioning

confidence: 99%

In-line measurement of multiphase flow viscosity

et al. 2022

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The transportation modes depend entirely on the viscosity of the oil. To date, none of the viscometric methods are able to provide measurements to meet all the requirements of oil flow, features of main oil pipelines, and trends in the oil industry, such as decarbonization and digitalization. The method of inline viscosity measurement of multiphase flow through a metal pipeline can be based on direct gamma ray measurement. It is stipulated by the ability of gamma-radiation to penetrate through the pipeline material without destroying it, as well as by the ability to work with flows containing free gas and the high capability to be introduced into automatic control systems. The authors consider the physical forces acting on the gas inclusions in the oil flow. They determine the physical dependence between the parameters determined by the radioisotope method and the viscosity of oil in the three-phase flow. These studies show good agreement with the work of other scientists. The prospect of further research will be to clarify the mathematical model of gas-oil flow, to increase the accuracy by reducing the number of assumptions made.

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“…Based on the laser invented in 1960s, as a noninvasive optical diagnostic technology, the study of local flow characteristics in stirred tanks has been greatly promoted . The laser–Doppler anemometer technology was adopted by Yianneskis et al to conduct detailed tests on the flow characteristics in a Rushton turbine stirred tank, where two opposite ring vortices called circulated flows were found on the upper and lower blades, and the impeller flow between two circulated flows had a certain inclined angle in the horizontal direction.…”

Section: Introductionmentioning

confidence: 99%

“…11−16 Based on the laser invented in 1960s, as a noninvasive optical diagnostic technology, the study of local flow characteristics in stirred tanks has been greatly promoted. 17 The laser−Doppler anemometer technology was adopted by Yianneskis et al 10 to conduct detailed tests on the flow characteristics in a Rushton turbine stirred tank, where two opposite ring vortices called circulated flows were found on the upper and lower blades, and the impeller flow between two circulated flows had a certain inclined angle in the horizontal direction. Detailed unstable flow features, such as trailing vortices behind the blades and vortex behind the baffles were observed, which have been reported earlier than Doulgerakis et al 18 However, such local flow pattern characteristics are difficult to predict by numerical simulation at that moment, especially for small-scale vortices.…”

Section: Introductionmentioning

confidence: 99%

Numerical Investigation of Particle Suspensions in a Liquid–Solid Stirred Tank with Baffles

Wang

Zhao

2021

Ind. Eng. Chem. Res.

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Stirred vessels have been widely used in the chemical and process industries, while particle suspensions in a liquid−solid stirred tank with baffles have little been studied. In this work, a particle suspension in a standard stirred tank driven by a Rushton turbine was simulated using large eddy simulation coupled with the Lagrangian particle tracking technique. The rotation speed was N = 313 rpm, and three particle sizes ranging from 200 to 2500 μm (St = 0.24−37.3) were considered. The simulation results including the flow field and particle concentration showed good agreement with the experimental data. Turbulent flows were found in the wake region formed by the impeller sweep, and double trailing vortices behind the impeller blades were visualized. Three particle suspension states were found as quasi-homogeneous, complete, and incomplete suspensions. Impeller rotation produced strong turbulence and vortex to promote particle dispersion and particle mixing, where the dual circulated flow drove the particles to suspend in the tank. Small particles (St = 0.24) and medium particles (St = 2.6) tended to have a large drag force that caused preferential concentration around the trailing vortex, while large particles (St = 37.3) were hardly driven by the circulated flow, so their concentration gradient varied from 0 to 2 orders of magnitude.

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Simultaneous measurements of liquid velocity and tracer concentration in a continuous flow stirred tank

Cited by 15 publications

References 22 publications

Testing Basic Gradient Turbulent Transport Models for Swirl Burners Using PIV and PLIF

Testing Basic Gradient Turbulent Transport Models for Swirl Burners Using PIV and PLIF

In-line measurement of multiphase flow viscosity

Numerical Investigation of Particle Suspensions in a Liquid–Solid Stirred Tank with Baffles

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