Numerical solution of three-dimensional rectangular submerged jets with the evidence of the undisturbed region of flow

Angelino, Matteo; Boghi, Andrea; Gori, Fabio

doi:10.1080/10407782.2016.1214494

Cited by 25 publications

(40 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The new flow evolution of the jet can be important in several heat transfer applications: as a jet impinging a single smooth cylinder, [22][23][24][25][26][27][28], a finned cylinder, [29][30][31][32][33]; two cylinders in a row, [34][35]; and three cylinders in a row, [36][37]. The numerical results of [38][39][40][41][42] confirmed that the URF, as well as the NDF and SDF, are predictable numerically.…”

Section: Introductionmentioning

confidence: 84%

Numerical simulation of mass transfer and fluid flow evolution of a rectangular free jet of air

Venuta

Petracci

Angelino

et al. 2018

International Journal of Heat and Mass Transfer

View full text Add to dashboard Cite

The paper presents the Large Eddy Simulation (LES) of mass transfer and fluid flow evolution of a submerged rectangular free jet of air in the range of Reynolds numbers from Re = 3400 to Re = 22,000, with the Reynolds number, Re, defined with the hydraulic diameter of the rectangular slot, of height H. The numerical simulation is 3D for Re=3400 and 6800, while 2D for Re=10,400 and 22,000 to reduce computational time costs. The average and instant LES numerical simulations compare concentration visualizations, obtained with the Particle Image Velocimetry (PIV) technique, and fluid dynamics variables, velocity and turbulence, measured with the Hot Film Anemometry (HFA). In the numerical simulations, the Schmidt number is equal to 100 to compare the air concentration PIV experiments, while the turbulence on the exit of the slot is equal to the value measured experimentally, ranging between 1% and 2%. The average 2-3D LES simulations are in agreement with the concentration and fluid dynamics experimental results in the Undisturbed Region of Flow (URF) and in the Potential Core Region (PCR), while the vortex breakdown is captured only by the 3D approach. As far as the instant flow evolution is concerned, the 2-3D LES simulations reproduce the Negligible Disturbances Flow (NDF), where the jet height maintains constant, and the Small Disturbances Flow (SDF), where the jet height oscillates, with contractions and enlargements, but without the vortex formation. Average and instant velocity and turbulence numerical simulations on the centreline are in good agreement to the experimental measurements. Keywords: 2-3D Large Eddy Simulations; Transitional to turbulent flow; Numerical concentration fields and comparisons with PIV visualizations; Numerical fluid dynamics variables and comparison with HFA measurements; Confirmation of the URF in the average flow and NDF, SDF in the instant flow. Nomenclature Latin D diameter E turbulent energy spectrum

show abstract

Section: Introductionmentioning

confidence: 84%

Numerical simulation of mass transfer and fluid flow evolution of a rectangular free jet of air

Venuta

Petracci

Angelino

et al. 2018

International Journal of Heat and Mass Transfer

View full text Add to dashboard Cite

show abstract

“…Numerical investigations have been also able to reproduce the URF since Gori et al [35] undertake preliminary numerical investigations with the Reynolds Averaged Navier-Stokes (RANS) equations model. The URF has been investigated also with the Large Eddy Simulations (LES) approach, at several Reynolds numbers, in order to verify the occurrence of URF, [36][37]. One of the main achievement of the last two studies was to show that the velocity profile in the URF obeys to a self-similar law, different from those proposed by Tollmien [15] and Görtler [16] for the PCR.…”

mentioning

confidence: 99%

Passive scalar diffusion in the near field region of turbulent rectangular submerged free jets

Boghi

Venuta

Gori

2017

International Journal of Heat and Mass Transfer

View full text Add to dashboard Cite

Jets are a common way to transfer mass among fluids, or from a fluid to a surface. At moderate Reynolds numbers and low turbulent intensities the jet exhibits a Near Field Region (NFR) several diameters long. Numerical results and a theoretical model are presented for the passive scalar diffusion in the NFR of a submerged free jet. Large Eddy Simulations (LES), in the Reynolds number 5000-40,000 and the Schmidt number range 1-100, are performed obtaining the passive scalar fields. Three mathematical models for the passive scalar diffusion are presented; the first one is valid in the NFR, specifically in the Undisturbed Region of Flow (URF), and the other two, obtained under the hypotheses of Tollmien and Görtler momentum spreadings, are valid in the Potential Core Region (PCR). The last two models employ a turbulent Schmidt number inversely proportional to the mean velocity gradient, conclusion obtained by the LES numerical results. The self-similar solutions of the passive scalar show good agreement with the LES results. The wide range of Reynolds and Schmidt numbers investigated gives generality to the results.

show abstract

“…For T = 0F , some turbulence is present in the oil jet (k 1m 2 /s 2 ) but it is dissipated one pipe diameter downstream the bypass (k 10 −3 m 2 /s 2 ). For T ≥ 25F the characteristic turbulent mixing layer at the jet boundary and the potential core region, of triangular shape, at the center of the jet can be observed (Gori et al, 2012;Angelino et al, 2016;Boghi et al, 2016Boghi et al, , 2017b. For T ≥ 25F the jet bends towards the top of the pipe.…”

Section: Results At 2mm Wax Particle Diametermentioning

confidence: 97%

“…In the present study, the velocity at the center of the oil jet is about 300 times higher than the pig velocity. Despite the jet axial velocity diminishes with the increasing distance (Gori et al, 2012;Boghi et al, 2016;Angelino et al, 2016;Boghi et al, 2017b), the acceleration gained in proximity of the pig blasts the wax chips much further downstream compared to the sealing pig. This prevents the deposit from piling up in front of the pig.…”

Section: Discussionmentioning

confidence: 99%

A non-inertial two-phase model of wax transport in a pipeline during pigging operations

Boghi

Brown²,

Sawko³

et al. 2018

Journal of Petroleum Science and Engineering

View full text Add to dashboard Cite

The removal of wax deposit from pipelines is commonly accomplished using pigs. In order to avoid the formation of wax plugs in pipes, bypass pigs, which create a liquid jet to disperse the scraped deposit, are employed. Despite many One-Dimensional (1D) models have been developed to predict the dynamics of bypass pigs, the details of the interaction between the liquid jet and the debris have not been investigated numerically yet. In this work the fluid dynamics of a wax-in-oil slurry in front of a moving bypass pig is studied by means of three-dimensional (3D) numerical simulations. A mathematical model which couples the pig and the wax-in-oil slurry dynamics, solved in the pig frame of reference, has been developed. The results show that the pig quickly reaches an equilibrium velocity, and the pig acceleration is proportional to the square of the mixture relative velocity. Comparing the present with previous sealing-pig results it appears that the bypass flow is more effective in deterring plug formation. Moreover, the 3D fields have the advantage of showing the wax distribution in each pipe section whereas the 1D model cannot distinguish between deposited and suspended wax.

show abstract

Numerical solution of three-dimensional rectangular submerged jets with the evidence of the undisturbed region of flow

Cited by 25 publications

References 43 publications

Numerical simulation of mass transfer and fluid flow evolution of a rectangular free jet of air

Numerical simulation of mass transfer and fluid flow evolution of a rectangular free jet of air

Passive scalar diffusion in the near field region of turbulent rectangular submerged free jets

A non-inertial two-phase model of wax transport in a pipeline during pigging operations

Contact Info

Product

Resources

About