Discussion on appropriate material parameters for a porous media model of the IVD

PAMM ◽  
2007 ◽  
Vol 7 (1) ◽  
pp. 4020003-4020004
Author(s):  
Nils Karajan ◽  
Wolfgang Ehlers
Keyword(s):  
Porous Media ◽  
Material Parameters ◽  
Porous Media Model

Numerical Simulation of Airborne Salt Particle Behavior in Dry Gauze Method Using Porous Media Model

2021 ◽  
pp. 1-37
Author(s):  
Yuta Tsubokura ◽  
Kyohei Noguchi ◽  
Tomomi Yagi
Keyword(s):  
Porous Media ◽  
Flow Field ◽  
Collection Efficiency ◽  
Steel Structures ◽  
Salt Particle ◽  
Wooden Frame ◽  
Collection Device ◽  
Porous Media Model ◽  
Corrosion Of Steel ◽  
Porous Media Method

Abstract Airborne salt accelerates the corrosion of steel materials and, thus, must be quantitatively evaluated for the management of steel structures. In Japan, the dry gauze method, which uses a gauze embedded in a wooden frame, is often used to evaluate the amount of airborne salt. However, its collection efficiency for salt particles has not been verified owing to the complex airflows around the device. Therefore, as a first step to clarify the collection efficiency, the authors simulated the flow field around the collection device using computational fluid dynamics. In this study, the gauze was modeled as a porous medium to reduce the computational costs. Wind tunnel tests were performed to obtain the pressure loss coefficients of the gauze, which is necessary for the porous media method. Subsequently, particle tracking was performed in the calculated flow field, and the collection efficiency was evaluated under the condition of a filtration efficiency of 100%. The flow fields around the device were accurately reproduced using the porous media model, which considered both the tangential and normal resistances of the gauze. This result suggests that the tangential resistance must be considered in the porous media model when the porosity of an object is small, even if the thickness is small. The dependence of collection efficiency on wind speed and direction was quantitatively evaluated. The results showed that the collection efficiency was greatly affected by the complicated flow field around the device due to the combination of the gauze and wooden frame.

scholarly journals Waves and currents propagation through porous media: model experiments and scale effects

2015 ◽  
Author(s):  
Gwendoline ARNAUD ◽  
Vincent REY ◽  
Damien SOUS ◽  
Julien TOUBOUL ◽  
Fabrice GOUAUD
Keyword(s):  
Porous Media ◽  
Scale Effects ◽  
Model Experiments ◽  
Porous Media Model ◽  
Waves And Currents

Temperature Variation in Breast Tissue Model With and Without Tumor Based on Porous Media

2021 ◽  
Vol 4 (1) ◽  
pp. 61-75
Author(s):  
Sharmila Shrestha ◽  
Gokul K.C. ◽  
Dil Bahadur Gurung
Keyword(s):  
Porous Media ◽  
Temperature Variation ◽  
Breast Tissue ◽  
Normal Breast Tissue ◽  
Anterior Part ◽  
Skin Surface ◽  
Normal Breast ◽  
The Finite Element Method ◽  
Porous Media Model ◽  
Tumor Region

The human body is made by 200 different types of cells, which are separated by voids. Blood supplies the nutrients and minerals to all cells within the tissue through these voids. The breast tissue is treated as a porous media in the study. Tumor includes the vascular (blood) and the extra-vascular (solid) regions. The porosity of a tumor is higher than normal tissue. The present work deals with the temperature variation of normal and tumorous breast tissue based on porous media. The finite element method is used to solve the two-dimensional bio-heat equation. The results show that the temperature profile of normal breast tissue in the porous media model is almost identical with the conventional bio-heat model at correction factor is equal to 0:6. The temperature of tumor region in the porous media model is slightly lower than the conventional bio-heat model. When the porosity is increased, the temperature of normal breast tissue is increased. But in tumorous breast tissue, the temperature is slightly increased in skin surface to anterior part of the tumor and slightly decreased in tumor region. The temperature of normal and tumorous breast tissue is increased when metabolism, blood velocity, and room temperature are increased in the porous media model. The central temperature of the tumor region reaches a steady state faster than anterior and posterior temperature of both normal and tumorous breast tissue in conventional bio-heat model and porous media model.

Numerical Simulation Study on Battery-Casing Sealing Considering Rubber Aging

2020 ◽  
Vol 36 (6) ◽  
pp. 955-969
Author(s):  
Yijie Huang ◽  
Fei Guo ◽  
Yuchao Ke ◽  
Fangyong Wu ◽  
Xiaohong Jia ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Porous Media ◽  
Circular Arc ◽  
Sealing Material ◽  
Sealing Performance ◽  
Porous Media Model ◽  
New Energy ◽  
Key Factor ◽  
Grid Independence ◽  
New Energy Vehicles

ABSTRACTBattery-casing sealing is the key factor for secure travel of new energy vehicles. We constructed a relatively accurate mechanical-simulation model by selecting a constitutive model, analyzing the influence of thermal elongation, verifying the grid-independence and comparing numerically by the pressure-measurement film on the basis of studying the physical performance of a certain type of sealing material that had been used in battery-casings after aging. Based on a porous-media model and combined with changes of macroscopic and microscopic contact characteristics of materials at different times after aging, the evolution rule of sealing performance with time was analyzed quantitatively by calculating the leakage. By analyzing the structure of circular arc bulge on the surface of sealing material, the radius of circular arc bulge with better sealing performance was obtained, which could reduce the leakage of sealing structure during the material’s lifecycle.

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