Experimental investigation of flow development and coherent structures in normal and oblique impinging slot jets

Zhang, Xueqing; Yarusevych, Serhiy; Peterson, Sean D.

doi:10.1007/s00348-018-2653-6

Cited by 11 publications

(3 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…At x 0 , the average air velocity is zero; however, this does not exclude the existence of temporally varying turbulences (which, as we will see later, produce a very high mass/heat transfer). We note that the formation of such a stagnation point, and thus the presence of a flow in both directions, was confirmed for a large range of angles θ (15−90°) and Reynolds numbers (1000−7000). , It is crucial to point out that the whole setup is situated in a fume hood, operating under ambient conditions at an ∼30% relative humidity. It is well-known that the atmosphere can have an impact on morphology formation, degradation of hybrid perovskite precursor films, and performances of PSCs. , However, cost-effective industrial fabrication is conducted preferably in ambient air. , …”

Section: Resultsmentioning

confidence: 93%

“…The latter is not a free parameter but rather a property of the N 2 stream fully characterized by the parameters above. At x 0 , the average air velocity is zero; however, this does not exclude the existence of temporally varying turbulences 32 (which, as we will see later, produce a very high mass/heat transfer). We note that the formation of such a stagnation point, and thus the presence of a flow in both directions, was confirmed for a large range of angles θ (15−90°) and Reynolds numbers (1000−7000).…”

Section: Resultsmentioning

confidence: 99%

“…We note that the formation of such a stagnation point, and thus the presence of a flow in both directions, was confirmed for a large range of angles θ (15−90°) and Reynolds numbers (1000−7000). 32,33 It is crucial to point out that the whole setup is situated in a fume hood, operating under ambient conditions at an ∼30% relative humidity. It is well-known that T, the blading height, h 0 , the distance between the coater and the slot nozzle, L, and the dynamic web speed, v. The red, magnified view shows the parameters of the slot nozzle: its width, D, its height, H, its oblique angle, θ, and its gas outlet velocity, u 0 .…”

Section: Resultsmentioning

confidence: 99%

See 2 more Smart Citations

Drying and Coating of Perovskite Thin Films: How to Control the Thin Film Morphology in Scalable Dynamic Coating Systems

Ternes

Mohacsi

Lüdtke

et al. 2022

ACS Appl. Mater. Interfaces

View full text Add to dashboard Cite

Hybrid perovskite photovoltaics combine high performance with the ease of solution processing. However, to date, a poor understanding of morphology formation in coated perovskite precursor thin films casts doubt on the feasibility of scaling-up laboratory-scale solution processes. Oblique slot jet drying is a widely used scalable method to induce fast crystallization in perovskite thin films, but deep knowledge and explicit guidance on how to control this dynamic method are missing. In response, we present a quantitative model of the drying dynamics under oblique slot jets. Using this model, we identify a simple criterion for successful scaling of perovskite solution printing and predict coating windows in terms of air velocity and web speed for reproducible fabrication of perovskite solar cells of ∼15% in power conversion efficiencyin direct correlation with the morphology of fabricated thin films. These findings are a corner stone toward scaling perovskite fabrication from simple principles instead of trial and error optimization.

show abstract

Section: Resultsmentioning

confidence: 93%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Drying and Coating of Perovskite Thin Films: How to Control the Thin Film Morphology in Scalable Dynamic Coating Systems

Ternes

Mohacsi

Lüdtke

et al. 2022

ACS Appl. Mater. Interfaces

View full text Add to dashboard Cite

show abstract

Flow dynamics and heat transfer characteristics analysis for floatation nozzle using large eddy simulation and proper orthogonal decomposition method

Huang

Diao

Huang

et al. 2020

International Journal of Thermal Sciences

View full text Add to dashboard Cite

Characteristics of flow past elongated bluff bodies with underbody gaps due to varying inflow turbulence

2021

View full text Add to dashboard Cite

An experimental study was performed on two elongated bluff bodies with underbody gaps, a square-back Ahmed body and a cuboid, to investigate the effects of geometry and the approach flow conditions on the time-averaged and temporal characteristics. The flow fields produced from two approach turbulent boundary layers with moderate (∼4%) and high (∼7%) turbulence levels were studied using time-resolved and double-frame particle image velocimetry systems. With the moderate turbulence, the wake topology and the loci of the centroid of vortices exhibit the well-known toroidal structure behind the Ahmed body, though it is skewed away from the wall. Also, the regions of elevated Reynolds stresses are considerably larger in the upper shear layer compared to the lower shear layer due to the reduced underbody velocity. The dominant frequencies obtained from the velocity fluctuations, reverse flow area, and the coefficient of the first proper orthogonal decomposition (POD) mode are identical. The flow structures are more complex behind the cuboid and the Ahmed body mounted in the high turbulent flow due to the enhanced interaction between the lower and upper shear layers, which is also evident from the shape of the turbulent structures in these shear layers. Consequently, the dominant vortex shedding frequencies varied as the streamwise distance from the bodies increased. The probability density function of the reverse flow area and the POD analysis performed in the spanwise plane revealed that the bi-stability phenomenon is absent in the present study due to the significant modification of the wake topology.

show abstract

Experimental investigation of flow development and coherent structures in normal and oblique impinging slot jets

Cited by 11 publications

References 48 publications

Drying and Coating of Perovskite Thin Films: How to Control the Thin Film Morphology in Scalable Dynamic Coating Systems

Drying and Coating of Perovskite Thin Films: How to Control the Thin Film Morphology in Scalable Dynamic Coating Systems

Flow dynamics and heat transfer characteristics analysis for floatation nozzle using large eddy simulation and proper orthogonal decomposition method

Characteristics of flow past elongated bluff bodies with underbody gaps due to varying inflow turbulence

Contact Info

Product

Resources

About