Validation of a mathematical and numerical model for dynamic 1-D moisture content evolution in layered building elements

2002 ◽  
Vol 35 (7) ◽  
pp. 382-388 ◽  
Author(s):  
R. Becker
Keyword(s):  
Numerical Model ◽  
Moisture Content ◽  
Building Elements

scholarly journals Effect of Moisture Content on Calculated Dielectric Properties of Asphalt Concrete Pavements from Ground-Penetrating Radar Measurements

2021 ◽  
Vol 14 (1) ◽  
pp. 34
Author(s):  
Qingqing Cao ◽  
Imad L. Al-Qadi
Keyword(s):  
Dielectric Properties ◽  
Numerical Model ◽  
Moisture Content ◽  
Ground Penetrating Radar ◽  
Asphalt Concrete ◽  
Concrete Pavements ◽  
Proposed Model ◽  
Moisture Variation ◽  
Ground Penetrating ◽  
Non Destructive

Moisture presence in asphalt concrete (AC) pavement is a major cause of damage to the pavement. In recent decades, an increasing need exists for non-destructive detection and monitoring of the moisture content in AC pavement. This paper provides a simulated approach to quantify the effect of internal moisture content on AC pavement dielectric properties using ground-penetrating radar (GPR). A heterogeneous numerical model was developed to simulate AC pavement with internal moisture at various saturation levels. The numerical model was validated using GPR surveys on cold-in-place recycling treated pavements. An empirical formula was derived from the simulation to correlate the dielectric constant with the moisture content for non-dry AC pavement. The results validated the proposed model and, hence, demonstrated the ability of GPR to monitor moisture variation in AC pavements.

Influence of wall composition on moisture related degradation of the wall surfaces in Hagia Sophia, Istanbul

2021 ◽  
pp. 174425912199601
Author(s):  
Etsuko Mizutani ◽  
Daisuke Ogura ◽  
Takeshi Ishizaki ◽  
Masaru Abuku ◽  
Juni Sasaki
Keyword(s):  
Numerical Model ◽  
Environmental Factors ◽  
Moisture Content ◽  
Moisture Diffusivity ◽  
Wall Paintings ◽  
High Moisture Content ◽  
High Moisture ◽  
Water Permeation ◽  
Salt Crystallisation ◽  
Hagia Sophia

Over the past 10 years, our research team has holistically studied the environmental aspects of the conservation and restoration of the Hagia Sophia, which is suffering from severe degradation of its wall paintings, including the exfoliation of wall paintings and inner finishing materials, mainly due to salt crystallisation. In the present study, we investigated the influence of environmental factors and wall composition on the hygrothermal behaviour in the structure, such as moisture accumulation and evaporation within the walls, which significantly affect salt crystallisation. The differences in distribution of high moisture content at second cornice are depending on the azimuth, and the high correlation between high moisture content and deterioration severity is significant. A two-dimensional numerical model of the simultaneous transfer of heat and moisture considering the measured material physical properties and wall composition of the exedra wall is developed to quantitatively investigate the influence of environmental factors on moisture accumulation. Numerical results show that infiltrated rainwater tends to accumulate because the original builders used connection mortar, which has a much larger moisture diffusivity than that of modern mortar, and the accumulated water at the bottom of the wall is difficult to drain owing to the shape of the wall. In the northwest exedra, the influence of wind-driven rain on water accumulation is similar to that of runoff rainwater from the upper roofs, which probably causes deterioration over a wide area. In addition, the effect of the deterioration suppression measure by the re-covering of the outer surfaces of the west wall in 2013 is verified, and an appropriate suppression measure against water permeation is examined using a numerical model.

Slope Cracks in the Safety Assessment of the Rainfall Period

2013 ◽  
Vol 405-408 ◽  
pp. 2364-2369 ◽  
Author(s):  
Te Hsing Chang ◽  
Chi Li Lin ◽  
Fu Kuo Huang
Keyword(s):  
Shear Strength ◽  
Numerical Model ◽  
Moisture Content ◽  
Slope Stability ◽  
Groundwater Level ◽  
Safety Assessment ◽  
Pore Water Pressure ◽  
Water Cycle ◽  
Water Pressure ◽  
Cycle System

Unsaturated cracked slopes are easily to be affected by rainfall in the soil. Actually, some of the rainfall becomes the surface runoff and the rest permeates the crack under the ground in water cycle system. The infiltration makes the groundwater level rise. It also increases the pore water pressure and slide stress of the soil and decreases the anti-shear strength of soil. That makes the slope fracture or deform. However, most of the slope stability analyses set the physical properties of the soil as constant values but neglect the influence of the crack and infiltration. Those analyses underestimate the influence of the crack and the change of water content to the anti-shear strength of the soil. Therefore, it was unable to predict the possible damage time point by these evaluation results. The knowledge and methodology of the rainfall combine infiltration and slope stability analysis in this research. Simulations of the moisture content of the soil and the groundwater level are performed by FEMWATER numerical model. The simulating conditions are based on the different cracked positions and rainfall durations. The data of moisture content changes of the soil will be transformed into the parameters of safety factors fitted by STEDWIN numerical model. The influence of the slope stability with different cracked positions was gained from the simulations.

scholarly journals Numerical investigation of vapor phase drzing process for drying of transformer’s insulation paper

2020 ◽  
Vol 24 (3 Part B) ◽  
pp. 2125-2135
Author(s):  
Cemil Yigit ◽  
Ahmet Aydin ◽  
Halit Yasar ◽  
Fatih Isik ◽  
Tahsin Engin
Keyword(s):  
Numerical Model ◽  
Moisture Content ◽  
Vapor Phase ◽  
Cycle Time ◽  
Theoretical Calculations ◽  
Thermal Calculation ◽  
Drying Process ◽  
Effective Use ◽  
Time And Energy ◽  
Drying Chamber

The moisture content of oil-filled transformers insulation paper that is a cellulose-containing material comprises 8% to 10% of moisture by weight at ambient temperature and it is highly important to decrease the moisture content for effective use of a transformer. Vapor phase drying is more effective method for drying the insulation paper of the transformer as compared with other conventional methods due to less cycle time and energy consumption. The purpose of this paper is to design a solvent operated drying chamber in which drying of the insulation paper of oil filled transformer carried out. The approach of the present paper is to develop a numerical model to reduce the cycle time of the drying process. The unsteady flow, heat, and mass transfer phenomena were simulated by using CFD solver. Theoretical studies and a numerical model were conducted over thermal calculation in the drying process using solvent at different pressures. Theoretical calculations were used to validate the numerical model. Drying chamber was optimized by using response surface methodology. The result of the study showed that drying cycle time was decreased almost 14.3% with the new design. Furthermore, when the solvent was used instead of air as a heat carrier, the drying cycle time was reduced.

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