Calculation of the maximum moisture buffering thickness of building wall layer of hygroscopic material

2019 ◽  
Vol 160 ◽  
pp. 106173 ◽  
Author(s):  
Hang Wan ◽  
Zhongwei Sun ◽  
Gongsheng Huang ◽  
Xinhua Xu ◽  
Jinghua Yu
Keyword(s):  
Wall Layer ◽  
Building Wall ◽  
Hygroscopic Material ◽  
Moisture Buffering

Development of a simplified dynamic moisture transfer model of building wall layer of hygroscopic material

Energy ◽  
2019 ◽  
Vol 183 ◽  
pp. 1278-1294 ◽  
Author(s):  
Tian Yan ◽  
Zhongwei Sun ◽  
Xinhua Xu ◽  
Hang Wan ◽  
Gongsheng Huang
Keyword(s):  
Moisture Transfer ◽  
Wall Layer ◽  
Transfer Model ◽  
Building Wall ◽  
Hygroscopic Material

Optimal moisture buffering thickness of the hygroscopic material layer: Modeling and derivation

2021 ◽  
pp. 108257
Author(s):  
Hang Wan ◽  
Gongsheng Huang ◽  
Sheng Liu ◽  
Shiguang Fan ◽  
Xinhua Xu ◽  
...  
Keyword(s):  
Material Layer ◽  
Hygroscopic Material ◽  
Moisture Buffering

Moisture buffering effect of hygroscopic materials under wall moisture transfer

2020 ◽  
pp. 1420326X2097583
Author(s):  
Ming Yang ◽  
Fanhong Kong ◽  
Xuancheng He
Keyword(s):  
Moisture Transfer ◽  
Buffering Capacity ◽  
High Moisture ◽  
Buffering Effect ◽  
Hygroscopic Material ◽  
The Difference ◽  
Room Model ◽  
Interior Finish ◽  
Moisture Buffering ◽  
Humidity Environment

Hygroscopic material can moderate the indoor humidity variation due to its moisture buffering effect. This effect would change when used as interior finish mainly due to air exchange and wall moisture transfer. The author focused on clarifying the extent of the wall'’s influence on indoor moisture buffering and building humidity environment. A room model was established and the situation of no wall moisture transfer was simulated by adding a vapour barrier between the interior finish and the wall. Comparing this result with wall moisture transfer, the moisture buffering effect of the wall can be quantitatively analysed. The results verify that the buffering effect and the humidity environment, especially the seasonal buffering, change with the wall moisture transfer. The wall has great impacts on buffering in the cases of thin interior finish, high moisture production and low ventilation. Because the layer under the hygroscopic material also has buffering capacity, the difference of using various thicknesses of material is not obvious. Frequent ventilation reduces the buffering effect but improves the RH optimality.

Comparing selected parameters of a two-dimensional turbulent free jet on the basis of experimental results, digital simulations, and theoretical analyses

2016 ◽  
Vol 1 (20) ◽  
pp. 31-48
Author(s):  
Aldona Skotnicka-Siepsiak
Keyword(s):  
Linear Function ◽  
Analytical Methods ◽  
Relative Length ◽  
Wall Layer ◽  
Turbulence Level ◽  
Two Dimensional ◽  
Free Jet ◽  
Theoretical Assumptions ◽  
Digital Simulations ◽  
Theoretical Analyses

The presented experimental and digital examinations of a two-dimensional turbulent free jet are a first phase of in the study of the Coandă effect and its hysteresis. Additionally, basing on theoretical analyses, selected results for a turbulent jest have been also mentioned, considering theoretical assumptions for the wall layer. As the result, on the basis of experimental, digital, and analytical methods, a review of characteristic jet properties has been prepared, which includes a jet spreading ratio, its cross and longitudinal sections, and turbulence level. The jet spreading radio has been expressed as a non-linear function of the x : b relative length.

Simulating flow separation from continuous surfaces: routes to overcoming the Reynolds number barrier

2009 ◽  
Vol 367 (1899) ◽  
pp. 2885-2903 ◽  
Author(s):  
Michael Leschziner ◽  
Ning Li ◽  
Fabrizio Tessicini
Keyword(s):  
Reynolds Number ◽  
Turbulent Flows ◽  
Major Elements ◽  
Wall Layer ◽  
Navier Stokes ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Rans Models ◽  
High Reynolds ◽  
Near Wall

This paper provides a discussion of several aspects of the construction of approaches that combine statistical (Reynolds-averaged Navier–Stokes, RANS) models with large eddy simulation (LES), with the objective of making LES an economically viable method for predicting complex, high Reynolds number turbulent flows. The first part provides a review of alternative approaches, highlighting their rationale and major elements. Next, two particular methods are introduced in greater detail: one based on coupling near-wall RANS models to the outer LES domain on a single contiguous mesh, and the other involving the application of the RANS and LES procedures on separate zones, the former confined to a thin near-wall layer. Examples for their performance are included for channel flow and, in the case of the zonal strategy, for three separated flows. Finally, a discussion of prospects is given, as viewed from the writer's perspective.

scholarly journals How Can We Manage Gallbladder Lesions by Transabdominal Ultrasound?

Diagnostics ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 784
Author(s):  
Shinji Okaniwa
Keyword(s):  
High Frequency ◽  
Layer Structure ◽  
Wall Layer ◽  
Pancreaticobiliary Maljunction ◽  
Doppler Imaging ◽  
Wall Thickening ◽  
Contrast Enhanced ◽  
Postural Changes ◽  
Venous Phase

The most important role of ultrasound (US) in the management of gallbladder (GB) lesions is to detect lesions earlier and differentiate them from GB carcinoma (GBC). To avoid overlooking lesions, postural changes and high-frequency transducers with magnified images should be employed. GB lesions are divided into polypoid lesions (GPLs) and wall thickening (GWT). For GPLs, classification into pedunculated and sessile types should be done first. This classification is useful not only for the differential diagnosis but also for the depth diagnosis, as pedunculated carcinomas are confined to the mucosa. Both rapid GB wall blood flow (GWBF) and the irregularity of color signal patterns on Doppler imaging, and heterogeneous enhancement in the venous phase on contrast-enhanced ultrasound (CEUS) suggest GBC. Since GWT occurs in various conditions, subdividing into diffuse and focal forms is important. Unlike diffuse GWT, focal GWT is specific for GB and has a higher incidence of GBC. The discontinuity and irregularity of the innermost hyperechoic layer and irregular or disrupted GB wall layer structure suggest GBC. Rapid GWBF is also useful for the diagnosis of wall-thickened type GBC and pancreaticobiliary maljunction. Detailed B-mode evaluation using high-frequency transducers, combined with Doppler imaging and CEUS, enables a more accurate diagnosis.

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