Wall shear rates and mass transfer in impinging jets: Comparison of circular convergent and cross-shaped orifice nozzles

Kristiawan, Magdalena; Meslem, Amina; Năstase, Ilinca; Sobolı́k, V.

doi:10.1016/j.ijheatmasstransfer.2011.09.014

Cited by 38 publications

(42 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The small working electrode is situated at the impinged surface and the size of the diffusion current is proportional to the molar flux of ion exchange and, at some conditions, it is also proportional to the heat transfer coefficient. The limiting diffusion current can be used to determine the shear stress (rate) at the location of the working electrode, see for example [17][18][19][20]. Using the analogy between mass and heat transfer, the heat transfer characteristics can be determined [21].…”

Section: Experimental Methodsmentioning

confidence: 99%

Heat transfer measurements and CFD simulations of an impinging jet

Petera

Dostál

2016

EPJ Web of Conferences

View full text Add to dashboard Cite

Abstract. Heat transport in impinging jets makes a part of many experimental and numerical studies because some similarities can be identified between a pure impingement jet and industrial processes like, for example, the heat transfer at the bottom of an agitated vessel. In this paper, experimental results based on measuring the response to heat flux oscillations applied to the heat transfer surface are compared with CFD simulations. The computational cost of a LES-based approach is usually too high therefore a comparison with less computationally expensive RANS-based turbulence models is made in this paper and a possible improvement of implementing an anisotropic explicit algebraic model for the turbulent heat flux model is evaluated.

show abstract

Section: Experimental Methodsmentioning

confidence: 99%

Heat transfer measurements and CFD simulations of an impinging jet

Petera

Dostál

2016

EPJ Web of Conferences

View full text Add to dashboard Cite

show abstract

“…It has already been shown in our previous investigation of an impinging jet that a jet from a crossshaped orifice nozzle significantly increases the wall shear rate and stagnation mass transfer, 6 compared to a reference jet from a convergent nozzle [44]. The hemispherical surface with a crossshaped orifice considered in the present study was designed to increase the stretching of the shearlayer at the jet exit in order to generate efficient jet dynamics in terms of wall skin friction and mass transfer.…”

Section: Introductionmentioning

confidence: 95%

“…The hemispherical surface with a crossshaped orifice considered in the present study was designed to increase the stretching of the shearlayer at the jet exit in order to generate efficient jet dynamics in terms of wall skin friction and mass transfer. To ensure continuity with the previous investigation [44], we chose a similar jet…”

Section: Introductionmentioning

confidence: 99%

“…The wall shear stress and the local mass transfer distributions were measured using electrodiffusion technique (ED), the same method we used before [44]. Phares et al [39] made a critical survey of different techniques used for the measurement of wall shear stress and concluded that ED provided the greatest accuracy of any indirect method.…”

Section: Introductionmentioning

confidence: 99%

“…In our previous study [44], only the stagnation mass transfer has been provided and has been 7 deduced from the slope of the radial wall shear rate distribution. In the present study, the radial mass transfer distribution along with global mass transfer are measured directly using the ED method.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Impinging cross-shaped submerged jet on a flat plate: a comparison of plane and hemispherical orifice nozzles

et al. 2015

Self Cite

View full text Add to dashboard Cite

To cite this version:Kodjovi Sodjavi, Brice Montagné, Pierre Bragança, Amina Meslem, Florin Bode, et al.. Impinging cross-shaped submerged jet on a flat plate: a comparison of plane and hemispherical orifice nozzles. Meccanica, Springer Verlag, 2015, pp.1-21. 10 AbstractIt is well known that the transfer of heat, mass and momentum to a wall by an impinging jet is partially linked to the way in which jet generation is realized. The organization of the vortices at the jet exit depends on the upstream conditions and on the geometry of the nozzle. Particle Image Velocimetry (PIV) and electrodiffusion techniques were used to investigate the characteristics of different impinging jets and the resulting wall shear rates and mass transfer. Two Cross-Shaped orifice jets, one produced by a plane orifice nozzle (i.e. a Cross-Shaped Orifice made on a flat Plate, CO/P) and the second by a hemispherical orifice nozzle (i.e. a Cross-Shaped Orifice made on a Hemisphere, CO/H), were compared to a reference round jet produced by a convergent nozzle. The distance between the jet exit and the target wall was equal to two nozzle equivalent diameters (De), based on the free orifice area. The Reynolds number, based on De and on the exit bulk-velocity, was 5620 for each flow. PIV measurements give an overall view of the flow characteristics in their free and wall regions. The switching-over phenomena observed in the CO/P nozzle case, and already described in the literature with similar nozzles, did not occur in the jet from the CO/H nozzle. Electrodiffusion measurements showed differences in the shape and level of radial distribution of the wall shear rates and mass transfer. One of the most important observations is the large difference in wall shear stress between the three jets. For the same exit bulk-velocity, the maximum wall shear rate in the CO/P and CO/H nozzle jets was almost two and three times higher, respectively, than that of the reference convergent jet. This higher wall shear rate is accompanied

show abstract

Passive control of wall shear stress and mass transfer generated by submerged lobed impinging jet

et al. 2015

Self Cite

View full text Add to dashboard Cite

Particle Image Velocimetry was used to investigate the flow field in an impinging lobed daisy hemispherical nozzle jet in comparison to its counterpart round jet, at a Reynolds number of 5620 based on the exit velocity and the equivalent diameter De of the nozzle.The limitations of the PIV technique in the vicinity of the target wall due to the laser scattering were addressed by using the electrodiffusion (ED) technique to determine the wall shear rate distribution. The distribution of the mass transfer coefficient is also obtained using the ED technique. The target wall is placed at a distance H = 2De from the plane tangent to the nozzle, at the center of the orifice. The entrainment of ambient fluid in the free jet region, which is larger in the lobed jet compared to the round jet, feeds in turn the wall jet region.The maximum wall shear rate was found significantly higher in the daisy jet, with an excess of 93% compared to the reference round jet. The maximum mass transfer is 35% higher in the former compared to the latter. Therefore, the hemispherical daisy nozzle is an excellent candidate in passive strategies to enhance local skin-friction and the subsequent local mass transfer at a constant exit Reynolds number.

show abstract

Wall shear rates and mass transfer in impinging jets: Comparison of circular convergent and cross-shaped orifice nozzles

Cited by 38 publications

References 20 publications

Heat transfer measurements and CFD simulations of an impinging jet

Heat transfer measurements and CFD simulations of an impinging jet

Impinging cross-shaped submerged jet on a flat plate: a comparison of plane and hemispherical orifice nozzles

Passive control of wall shear stress and mass transfer generated by submerged lobed impinging jet

Contact Info

Product

Resources

About