Modified thickness distribution model for large-diameter optical coatings

2015 ◽  
Vol 334 ◽  
pp. 115-117 ◽  
Author(s):  
Tong-Tong Wang ◽  
Jin-Song Gao
Keyword(s):  
Thickness Distribution ◽  
Large Diameter ◽  
Distribution Model ◽  
Optical Coatings

scholarly journals On the modelling of ice-thickness redistribution

2000 ◽  
Vol 46 (154) ◽  
pp. 427-437 ◽  
Author(s):  
Jari Haapala
Keyword(s):  
Baltic Sea ◽  
Numerical Experiments ◽  
Thickness Distribution ◽  
Distribution Model ◽  
Ice Thickness ◽  
The Baltic Sea ◽  
Pack Ice ◽  
Basin Scale ◽  
The Baltic ◽  
Ice Production

AbstractAn ice-thickness distribution model based on physical ice classes is formulated. Pack ice is subdivided into open water, two different types of undeformed ice, and rafted, rubble and ridged ice. Evolution equations for each ice class are formulated and a redistribution between the ice classes is calculated according to a functional form depending on the ice compactness, thickness and velocity divergence. The ice-thickness distribution model has been included in a coupled ice–ocean model, and numerical experiments have been carried out for a simulation of the Baltic Sea ice season. The extended ice classification allows separation of thermally and mechanically produced ice. Inherent thermodynamic growth/melting rates of the ice classes can be introduced into the model, giving a more detailed seasonal evolution of the pack ice. In addition, the model provides more information about the surface properties of pack ice.Numerical experiments for the Baltic Sea show that both the sub-basin and inter-basin ice characteristics were realistically simulated by the model. Deformed-ice production was related to storm activity. Most of the deformation was produced in the coastal zone, which is also an important region for thermodynamically produced ice because of the ice growth in leads. The modelled mechanical growth rates of ice were 0.5–3 cm d−1 on a basin scale, close to the thermodynamic ice-production rates. The deformed-ice fraction was 0.2 in mid-winter and increased to 0.5–1.0 during spring.

scholarly journals Analysis of Film Forming Law and Characteristics for an Air Static Spray with a Variable Position of the Plane

Coatings ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1236
Author(s):  
Yi Liu ◽  
Yong Zeng ◽  
Xueya Zhao ◽  
Jiuxuan Liu ◽  
Dezhi Liu
Keyword(s):  
Liquid Velocity ◽  
Thickness Distribution ◽  
Euler Method ◽  
Spray Angle ◽  
Distribution Model ◽  
Near Surface ◽  
Spray Process ◽  
Large Influence ◽  
Air Gun ◽  
Film Forming

In order to accurately establish the film thickness distribution model of a static spraying plane with air gun displacement, the film forming law and characteristics of the static spraying plane with air gun displacement were analyzed. The spray simulation model was established by the Euler–Euler method, and the spray process and film forming condition were calculated. The numerical simulation results show that oblique spraying has a large influence on the near-surface liquid velocity. With the increase in the spray angle, the droplets at the edge of the torch diffuse to the inclined direction, and the uniformity of the coating distribution becomes worse. Spraying height has a large influence on droplet trajectory. The coating thickness decreased significantly with the increase in spraying height, and the coating diffused in the air increased. With the increase in spraying height, the more obvious the droplet diffusion at the edge of the torch, the worse the uniformity quality of the coating. In order to ensure better spraying quality, the spraying height and angle should be controlled within a reasonable range at the same time. Spraying experiments verified the film forming law and characteristics of static spraying with gun displacement.

scholarly journals Towards Scalable Large-Area Pulsed Laser Deposition

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4854
Author(s):  
Zakhar Vakulov ◽  
Daniil Khakhulin ◽  
Evgeny Zamburg ◽  
Alexander Mikhaylichenko ◽  
Vladimir A. Smirnov ◽  
...  
Keyword(s):  
Film Thickness ◽  
Pulsed Laser Deposition ◽  
Thickness Distribution ◽  
Large Diameter ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Uniform Thickness ◽  
Technological Parameters ◽  
Distribution Profile ◽  
Thickness Uniformity

One of the significant limitations of the pulsed laser deposition method in the mass-production-technologies of micro- and nanoelectronic and molecular device electronic fabrication is the issue of ensuring deposition of films with uniform thickness on substrates with large diameter (more than 100 mm) since the area of the laser spot (1–5 mm2) on the surface of the ablated target is incommensurably smaller than the substrate area. This paper reports the methodology that allows to calculate the distribution profile of the film thickness over the surface substrate with a large diameter, taking into account the construction and technological parameters of the pulsed laser deposition equipment. Experimental verification of the proposed methodology showed that the discrepancy with the experiment does not exceed 8%. The modeling of various technological parameters influence on the thickness uniformity has been carried out. Based on the modeling results, recommendations and parameters are proposed for manufacturing uniform thickness films. The results allow for increasing the film thickness uniformity with the thickness distribution < 5% accounts for ~ 31% of 300 mm diameter substrate.

The Optimization of an Integrated Strut OGV Configuration

2014 ◽  
Author(s):  
Yadong Xie ◽  
Xiaohe Yang ◽  
Jianguo Ding ◽  
Xiaofeng Liu ◽  
Jinzhang Feng
Keyword(s):  
Guide Vane ◽  
Thickness Distribution ◽  
Large Diameter ◽  
Axial Direction ◽  
Maximum Diameter ◽  
Axial Distance ◽  
Recovery Coefficient ◽  
Maximum Thickness ◽  
Circumferential Distribution

In a core-mounted high-bypass ratio aero engine the bypass strut is designed to support the intermediate casing and to go the RDF (radial drive shaft) of a large diameter. Therefore the maximum thickness of the strut and maximum thickness distribution along the chord are restricted by the maximum diameter of the RDF. In order to enhance the total pressure recovery coefficient as well as reducing the backpressure circumferential variation, in this paper we describe the optimization of a datum configuration of the circumferential integrated strut OGV (Outlet Guide Vane). The datum configuration was designed based on an original configuration in which OGV and struts are separated axially. In the datum configuration, OGV is moved down-stream to be combined with the struts. The combined strut not only supports the casing as discussed above but also plays the role of turning the flow from the upstream fan to the axial direction. At the same time, the maximum thickness of the strut is about 8 times thicker than that of the OGV. The datum configuration will reduce noise because of larger axial distance between fan and OGVs as well as reducing weight because of fewer struts used in datum configuration. A re-staggering of OGV with sweep and dihedral both at the tip and hub will be used to optimize this datum configuration. Both datum configuration and optimized configuration will be compared with respected to the pressure loss included in the OGV and struts and the backpressure circumferential distribution variation.

scholarly journals Prediction of the Circumferential Film Thickness Distribution in Horizontal Annular Gas-Liquid Flow

2000 ◽  
Vol 122 (2) ◽  
pp. 396-402 ◽  
Author(s):  
Evan T. Hurlburt ◽  
Ty A. Newell
Keyword(s):  
Film Thickness ◽  
Liquid Film ◽  
Reynolds Stress ◽  
Thickness Distribution ◽  
Momentum Equation ◽  
Circumferential Direction ◽  
Liquid Film Thickness ◽  
Distribution Model ◽  
Low Velocity ◽  
Horizontal Pipe

This paper develops a liquid film symmetry correlation and a liquid film thickness distribution model for horizontal annular gas-liquid pipe flows. The symmetry correlation builds on the work of Williams et al. (1996) (Droplet Flux Distributions and Entrainment in Horizontal Gas-Liquid Flows,” Int. J. Multiphase Flow, Vol. 22, pp. 1–18). A new correlating parameter is presented. The liquid film thickness model is based on the work of Laurinat et al. (1985) (Film Thickness Distribution for Gas-Liquid Annular Flow in a Horizontal Pipe,” PhysicoChem. Hydrodynam., Vol. 6, pp. 179–195). The circumferential momentum equation is simplified to a balance between the normal Reynolds stress in the film’s circumferential direction and the circumferential component of the weight of the film. A model for the normal Reynolds stress in the circumferential direction is proposed. The symmetry correlation is used to close the model equations. The model is valid for films with disturbance waves, and is shown to be applicable to air-water flows over a range of conditions from low velocity asymmetric to high velocity symmetric annular flows. [S0098-2202(00)02102-7]

scholarly journals Sea ice floe size: its impact on pan-Arctic and local ice mass, and required model complexity

2021 ◽  
Author(s):  
Adam William Bateson ◽  
Daniel L. Feltham ◽  
David Schröder ◽  
Yanan Wang ◽  
Byongjun Hwang ◽  
...  
Keyword(s):  
Sea Ice ◽  
Size Distribution ◽  
Power Law ◽  
Large Scale ◽  
Prognostic Model ◽  
Thickness Distribution ◽  
Model Complexity ◽  
Distribution Model ◽  
Sea Ice Concentration ◽  
Advantages And Disadvantages

Abstract. Sea ice is composed of discrete units called floes. The size of these floes can determine the nature and magnitude of interactions between the sea ice, ocean, and atmosphere including lateral melt rate, momentum and heat exchange, and surface moisture flux. Large-scale geophysical sea ice models employ a continuum approach and traditionally either assume floes adopt a constant size or do not include an explicit treatment of floe size. Observations show that floes can adopt a range of sizes spanning orders of magnitude, from metres to tens of kilometres. In this study we apply novel observations to analyse two alternative approaches to modelling a floe size distribution (FSD) within the state-of-the-art CICE sea ice model. The first model considered, the WIPoFSD (Waves-in-Ice module and Power law Floe Size Distribution) model, assumes floe size follows a power law with a constant exponent. The second is a prognostic floe size-thickness distribution where the shape of the distribution is an emergent feature of the model and is not assumed a priori. We demonstrate that a parameterisation of in-plane brittle fracture processes should be included in the prognostic model. While neither FSD model results in a significant improvement in the ability of CICE to simulate pan-Arctic metrics in a stand-alone sea ice configuration, larger impacts can be seen over regional scales in sea ice concentration and thickness. We find that the prognostic model particularly enhances sea ice melt in the early melt season, whereas for the WIPoFSD model this melt increase occurs primarily during the late melt season. We then show that these differences between the two FSD models can be explained by considering the effective floe size, a metric used to characterise a given FSD. Finally, we discuss the advantages and disadvantages to these different approaches to modelling the FSD. We note that the WIPoFSD model is less computationally expensive than the prognostic model and produces a better fit to novel FSD observations derived from 2-m resolution MEDEA imagery but is unable to represent potentially important features of annual FSD evolution seen with the prognostic model.

Thickness Distribution Model of Condensate on Rotary Substrate by EB-PVD

2011 ◽  
Vol 418-420 ◽  
pp. 1031-1035
Author(s):  
Jun Shi ◽  
Guang Ping Song ◽  
Chuan Xin Zhang ◽  
Yue Sun ◽  
Xiu Lin ◽  
...  
Keyword(s):  
Physical Vapor Deposition ◽  
Thickness Distribution ◽  
Film Coating ◽  
Alloy Sheet ◽  
Measured Data ◽  
Distribution Model ◽  
Distribution Profile ◽  
Vapor Source ◽  
Large Size ◽  
Cosine Law

Large-size Ni-based alloy sheet was prepared by electron beam physical vapor deposition (EB-PVD). Thickness uniformity of large-size sheet for application is important. Based on the Knudsen’s cosine law and the character of the evaporation during EB-PVD, thickness distribution model of condensate on rotary substrate by EB-PVD was established. The thickness model is not consistent with the traditional cosine law, but cosnθ relationship, n=5.3 in this paper. The predicted data of thickness model agrees well with the measured data. The thickness distribution model is not limited to specific vapor source material, therefore, it provides significant insight on the thickness distribution profile for film, coating and sheet deposited on the rotary substrate by EB-PVD.

Photographic Equidensitometry of High Voltage Electron Images of Thick Noncrystalline Materials

1972 ◽  
Vol 30 ◽  
pp. 594-595
Author(s):  
Keinosuke Kobayashi
Keyword(s):  
High Voltage ◽  
Linear Response ◽  
Thickness Distribution ◽  
Contour Map ◽  
Mass Thickness ◽  
Voltage Electron ◽  
High Voltage Electron ◽  
Homogeneous Particle ◽  
Photographic Emulsions ◽  
Logarithmic Relation

Equidensitometry as developed by E. Lau and W. Krug has been little used in the analysis of ordinary electron photomicrographs, yet its application to the high voltage electron images proves merits of this procedure. Proper sets (families) of equidensities as shown in the next page are able to reveal the contour map of mass thickness distribution in thick noncrystalline specimens. The change in density of the electron micrograph is directly related to the mass thickness of corresponding area in the specimen, because of the linear response of photographic emulsions to electrons and the logarithmic relation between electron opacity and mass thickness of amorphous object.This linearity is verified by equidensitometry of a spherical solid object as shown in Fig. 1a. The object is a large (1 μ) homogeneous particle of polystyrene. Fig. 1b is a composite print of three equidensities of the 1st order prepared from Fig. 1a.

Sign in / Sign up

Export Citation Format

Share Document