Modeling wicking in textiles using the dual porosity approach

2018 ◽  
Vol 89 (17) ◽  
pp. 3519-3528 ◽  
Author(s):  
Marcelo Parada ◽  
Xiaohai Zhou ◽  
Dominique Derome ◽  
Rene Michel Rossi ◽  
Jan Carmeliet
Keyword(s):  
Moisture Content ◽  
Water Uptake ◽  
Mass Exchange ◽  
Dual Porosity ◽  
Richards Equation ◽  
Pore System ◽  
Complex Dynamic ◽  
Textile Structure ◽  
Cotton Textiles ◽  
Maximum Moisture Content

We develop a dual porosity diffusivity model to simulate the complex dynamic wicking behavior in textiles: wicking inside yarns coupled with wicking in the voids in between the yarns. The model expands the Richards equation to account for mass exchange between the two pore systems. This exchange, however, appears to be very small for cotton textiles and the system appears to behave as two parallel pore systems. The water uptake in the yarn pore system is mostly affected by the textile structure (woven versus knit), while the void pore system differs in the maximum moisture content that can be achieved during uptake. Gravity is shown to play an important role, especially for the coarser void pore system.

Relation between the maximum moisture content of coal and its porous structure

2016 ◽  
Vol 59 (11) ◽  
pp. 407-410 ◽  
Author(s):  
Ya. S. Balaeva ◽  
D. V. Miroshnichenko ◽  
Yu. S. Kaftan ◽  
V. M. Shmalko
Keyword(s):  
Moisture Content ◽  
Porous Structure ◽  
Maximum Moisture Content

Predicting the classification characteristics of coal. Part 2. Maximum moisture content

2015 ◽  
Vol 58 (12) ◽  
pp. 459-464 ◽  
Author(s):  
Ya. S. Balaeva ◽  
D. V. Miroshnichenko ◽  
Yu. S. Kaftan
Keyword(s):  
Moisture Content ◽  
Maximum Moisture Content

Dew on reindeer lichen

1991 ◽  
Vol 21 (9) ◽  
pp. 1415-1418 ◽  
Author(s):  
Gyula Péch
Keyword(s):  
Moisture Content ◽  
Meteorological Parameters ◽  
Ground Level ◽  
Meteorological Station ◽  
Mass Measurements ◽  
Moisture Contents ◽  
Hourly Rate ◽  
Simple Linear Relationship ◽  
Maximum Moisture Content ◽  
Reindeer Lichen

Four reindeer lichen (Cladinarangiferina (L.) Nyl) samples were placed near ground level in the open at a meteorological station where dew and other meteorological parameters were measured. One sample was covered occasionally from sunset to sunrise to prevent dew and to evaluate moisture gain due to wetting by atmospheric vapour alone. Mass measurements were done day and night following a set schedule. At the conclusion of the field program the samples were oven-dried and all weight measurements were converted to moisture contents. The results showed that a simple linear relationship adequately describes the overnight rise of lichen moisture caused by dew, and that atmospheric vapour alone, on nights without rain or condensation, can raise lichen moisture by 15%. Further, the results confirmed that nocturnal moisture gains by either dew or atmospheric vapour dissipate on subsequent clear mornings by noon. These findings suggest that at locations where humidity is measured at night and dew may be assessed visually in the morning, one can estimate both the 06:00 maximum moisture content of the lichen and, on subsequent clear mornings, the hourly rate of its drying.

Diffusive mass exchange of non-reactive substances in dual-porosity porous systems - column experiments under saturated conditions

2015 ◽  
Vol 30 (6) ◽  
pp. 914-926 ◽  
Author(s):  
Bastian Knorr ◽  
Piotr Maloszewski ◽  
Florian Krämer ◽  
Christine Stumpp
Keyword(s):  
Mass Exchange ◽  
Dual Porosity ◽  
Column Experiments

scholarly journals Pengaruh variasi kecepatan udara dan massa bahan terhadap waktu pengeringan jagung pada alat fluidized bed

2016 ◽  
Vol 6 (2) ◽  
Author(s):  
S. Syahrul ◽  
R. Romdhani ◽  
Mirmanto Mirmanto
Keyword(s):  
Moisture Content ◽  
Water Content ◽  
Fluidized Bed ◽  
Agricultural Products ◽  
Raw Material ◽  
Air Velocity ◽  
Drying Time ◽  
Post Harvest ◽  
Air Speed ◽  
Maximum Moisture Content

Indonesia is an agricultural country that has many agricultural products so that post-harvest handling is necessary so that the crop is not quickly broken when stored or distributed. One harvests in Indonesia, which require post-harvest handling such as corn. Based on SNI, the maximum moisture content of corn feed raw material has a moisture content of 14%. The water content of the corn used is 20% with a tolerance of ± 0.5%. Variations air speed used is 5 m /s, 6 m /s and 7 m /s with a variation of the mass of material that is 0.5 kg, 1 kg, and 1.5 kg. With the variation of air velocity and mass of the material showed that the higher the speed of the air, the faster drying time. In addition, the heavier material is drained, it will take longer. Variations of air velocity and mass of materials that require the fastest drying time is the air speed of 7 m /s with a mass of 0.5 kg. Variations of air velocity and mass of material that takes the longest drying air is at a speed of 5 m / s with a mass of 1.5 kg of material.

scholarly journals Optimizing Water Consumption in Richards’ Equation Framework with Step-Wise Root Water Uptake: A Simplified Model

2022 ◽  
Author(s):  
Marco Berardi ◽  
Marcello D’Abbicco ◽  
Giovanni Girardi ◽  
Michele Vurro
Keyword(s):  
Water Uptake ◽  
Water Consumption ◽  
Unsaturated Soils ◽  
Equilibrium Points ◽  
Root Water Uptake ◽  
Richards Equation ◽  
List Type ◽  
Algebraic Equations ◽  
Sink Term ◽  
Steady Solutions

Abstract This work arises from the need of exploring new features for modeling and optimizing water consumption in irrigation processes. In particular, we focus on water flow model in unsaturated soils, accounting also for a root water uptake term, which is assumed to be discontinuos in the state variable. We investigate the possibility of accomplishing such optimization by computing the steady solutions of a $$\theta$$ θ -based Richards equation revised as equilibrium points of the ODEs system resulting from a numerical semi-dicretization in the space; after such semi-discretization, these equilibrium points are computed exactly as the solutions of a linear system of algebraic equations: the case in which the equilibrium lies on the threshold for the uptake term is of particular interest, since the system considerably simplifies. In this framework, the problem of minimizing the water waste below the root level is investigated. Numerical simulations are provided for representing the obtained results. Article Highlights Root water uptake is modelled in a Richards’ equation framework with a discontinuous sink term. After a proper semidiscretization in space, equilibrium points of the resulting nonlinear ODE system are computed exactly. The proposed approach simplifies a control problem for optimizing water consumption.

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