• 제목, 요약, 키워드: Porous Media

검색결과 554건 처리시간 0.04초

A Review of Porous Media Theory from Woltmans Work to Biots Work

  • Park, Taehyo;Jung, Sochan
    • 한국지반환경공학회 논문집
    • /
    • v.4 no.2
    • /
    • pp.93-104
    • /
    • 2003
  • Porous media consist of physically and chemically different materials and have an extremely complicated behavior due to the different material properties of each of its constituents. In addition, the internal structure of porous materials has generally a complex geometry that makes the description of its mechanical behavior quite complex. Thus, classical continuum mechanics cannot explain the behavior of materials with pore spaces, such as concrete, soils and organic materials in waste landfill. For these reasons, porous media theory has been developed in the nineteenth century. Biot had the greatest influence on the development of porous media theory. Biot's work has been referred by many authors in the literature. Development of numerous fundamental equations in porous media theory were made possible due to Biot's work. His contributions made the greatest influence on porous media theory. Therefore, it is highly advantageous to review Biot's publications. This work presents a review of Biot's work. It shows how porous media theory has been developing so far and provides a chance to discuss the contribution of his work to the modern porous media theory.

  • PDF

포화 다공질 매체의 Arbitrary Lagrangian Eulerian (ALE) 정식화 (Arbitrary Lagrangian Eulerian (ALE) Formulations of Saturated Porous Media)

  • 박대효;정소찬
    • 한국전산구조공학회:학술대회논문집
    • /
    • /
    • pp.235-242
    • /
    • 2003
  • The solids and the fluids in porous media have a relative velocity to each other. Due to physically and chemically different material properties and their relative velocity, the behavior of saturated porous media is extremely complicated. Thus, in order to describe and clarify the deformation behavior of saturated porous media, constitutive models for deformation of porous media coupling several effects such as flow of the fluids or thermodynanical change need to be developed in frame of Arbitrary Lagrangian Eulerian (ALE) description. The aim of ALE formulations is to maximize the advantages of Lagrangian and Eulerian elements, and to minimize the disadvantages. Therefore, this method is appropriate for the analysis of porous media that are considered for the behavior of the solids and the fluids. In this work, governing equations of porous media based on ALE description are obtained from governing equations in frame of updated Lagrangian description. Then, weak forms of these equations are derived using arbitrary weighting functions.

  • PDF

Finite Element Formulation using Arbitrary Lagrangian Eulerian Method for Saturated Porous Media

  • Park, Taehyo;Jung, Sochan
    • 한국전산구조공학회:학술대회논문집
    • /
    • /
    • pp.375-382
    • /
    • 2003
  • Porous media consist of physically and chemically different materials and have an extremely complicated behavior due to the different material properties of each of its constituents. In addition, the internal structure of porous media has generally a complex geometry that makes the description of its mechanical behavior quite complex. Thus, in order to describe and clarify the deformation behavior of porous media, constitutive models for deformation of porous media coupling several effects such as flow of fluids of thermodynamical change need to be developed in frame of Arbitrary Lagrangian Eulerian (ALE) description. The aim of ALE formulations is to maximize the advantages of Lagrangian and Eulerian methods, and to minimize the disadvantages. Therefore, this method is appropriate for the analysis of porous media that are considered for the behavior of solids and fluids. First of all, governing equations for saturated porous media based on ALE description are derived. Then, weak forms of these equations are obtained in order to implement numerical method using finite element method. Finally, Petrov-Galerkin method Is applied to develop finite element formulation.

  • PDF

수처리용 다공성여재의 개발에 관한 연구 (The Study on Development of Porous Media for Water Treatment)

  • 이영신;정상철;홍성철
    • 한국환경보건학회지
    • /
    • v.23 no.4
    • /
    • pp.16-20
    • /
    • 1997
  • The purpose of this study is to develop of porous media for water treatment. It was made of porous media which was sinteringed on a comparative low temperature 600$\circ$C, was annexed slag (media-s) and humus soil (media-h) with material, only material kaolinite(media-k). In order to examine the characteristics of physical-chemical were used to sem, x-ray. The results of study are given porous size on media-h which was able to water treatment.

  • PDF

강제대류에 의해 냉각되는 다공물질의 열응답 특성 (Thermal response of porous media cooled by a forced convective flow)

  • 백진욱;강병하;현재민
    • 설비공학논문집
    • /
    • v.10 no.5
    • /
    • pp.600-609
    • /
    • 1998
  • The experimental investigation of thermal response characteristics by the air flow through the porous media has been carried out. The packed spheres of steel or glass were considered as the porous media in the present study. Temperature distributions of the fluid in the porous media as well as pressure drops through the porous media were measured. The transient temperature variations in the porous media are compared favorably with the analytical results in the high Reynolds number ranges. However, in the low Reynolds number ranges, the experimental data deviate from the analytical results, due to the dominant heat conduction penetration to the upstream direction, which is not considered in the analytical model. The cool-down response of porous media is found to be dependent upon the specific dimensionless time considering the material property and air velocity. The heat discharge process is recommended to be operated until a certain time, considering the cost efficiency.

  • PDF

포화된 다공질 매체의 질량 보존과 운동량 보존에 대한 Arbitrary Lagrangian Eulerian(ALE) 정식화 (Formulation of Mass Conservation and Linear Momentum Conservation for Saturated Porous Media in Arbitrary Lagrangian Eulerian(ALE) Description)

  • 박대효;정소찬;김원철
    • 한국지반환경공학회 논문집
    • /
    • v.4 no.1
    • /
    • pp.5-10
    • /
    • 2003
  • 다공질 매체 속의 내부 구조를 이루고 있는 고체 부분과 유체 부분은 서로 다른 재료특성을 가지는 물체들로 구성되어 있고 각 구성물들은 서로 다른 물리적 성질과 화학적 성질을 가지면서 서로 다른 상대 속도를 가지고 이동하기 때문에 포화된 다공질 매체의 구조적 변형 거동을 해석하는 것은 매우 복잡하다. 변형 거동에 영향을 주는 여러 가지 복합적인 요인들이 고려된 다공질 매체의 변형 거동을 해석하고 규명하기 위하여 Arbitrary Lagrangian Eulerian(ALE) 정식화가 이루어진 구성방정식을 세워야 할 필요가 있다. ALE 정식화는 Lagrangian 요소와 Eulerian 요소의 장점을 최대화 시키고 단점을 최소화 시키는 것에 주안점을 두기 때문에 고체 부분과 유체 부분을 함께 고려해야 하는 다공질 매체의 변형 거동을 해석하는데 있어서 적합한 방법이라고 할 수 있다. 그렇기 때문에 여기서는 포화된 다공질 매체의 보존 법칙들에 대한 ALE 정식화가 이루어진다. 고체 부분과 유체 부분의 질량 보존 법칙에 대하여 ALE 정식화가 이루어진 식이 각각 표현되고 다공질 매체 전체에 대한 운동량 보존 법칙이 표현된다.

  • PDF

S-ALE를 이용한 다공질 매체 거동의 유한요소해석 (Finite Element Analysis for Behavior of Porous Media Using the S-ALE Method)

  • 박대효;탁문호
    • 한국전산구조공학회:학술대회논문집
    • /
    • /
    • pp.381-388
    • /
    • 2006
  • A porous medium is composed of solids, fluids, and gas which have different physical and chemical properties. In addition, these constituents have a relative velocity between each other. So far, in order to analyze porous media using finite element method, Lagrangian or Eulerian method has been used. However, the numerical analyses for porous media have a defect that the methods do not describe the movements of constituents. In this paper, numerical analysis for unsaturated porous media was performed in frame of ALE method which has advantages of Lagrangian and Eulerian. Namely, the Lagrangian description was used in solid phase, and the Eulerian description was used in fluid or gas phase in a porous medium Then the relationship between each other was controlled by the convective term in ALE method. Finally, the numerical results of ALE were compared with tile results of Lagrangian analysis.

  • PDF

Study on relations between porosity and damage in fractured rock mass

  • Xue, Xinhua
    • Geomechanics and Engineering
    • /
    • v.9 no.1
    • /
    • pp.15-24
    • /
    • 2015
  • The porosity is often regarded as a linear function of fluid pressure in porous media and permeability is approximately looked as constants. However, for some scenarios such as unconsolidated sand beds, abnormal high pressured oil formation or large deformation of porous media for pore pressure dropped greatly, the change in porosity is not a linear function of fluid pressure in porous media, and permeability can't keep a constant yet. This paper mainly deals with the relationship between the damage variable and permeability properties of a deforming media, which can be considered as an exploratory attempt in this field.

소결다공체를 적용한 Closed Type 모사바이오파일시스템의 TPH 분해 특성 (Characteristics of TPH Decomposition in a Close-typed Simulated Biopile System Amended with a Sintered Porous Media)

  • 정현규;최상일;김상국;김혜진;김유범
    • 한국토양비료학회지
    • /
    • v.44 no.3
    • /
    • pp.415-424
    • /
    • 2011
  • This research was conducted to verified the effectiveness of a sintered porous media coated with organic matter as nutrient source and microorganisms as decomposer effective in TPH decomposition for a closed-typed biopole system. The organic matter content in the sintered porous media which was developed with bentonite increased with increasing dilution ratio of pig slurry and the sintered porous media as well as decrease in the particle size of sintered porous media. The decomposition rate of TPH was significantly increased with increasing aeration than that under atmospheric condition. Also the sintered porous media containing organic matter and microorganisms proved that the decomposition was enhanced with addition of nutrients sources in addition to aeration periodically.

Solution verification procedures for modeling and simulation of fully coupled porous media: static and dynamic behavior

  • Tasiopoulou, Panagiota;Taiebat, Mahdi;Tafazzoli, Nima;Jeremic, Boris
    • Coupled systems mechanics
    • /
    • v.4 no.1
    • /
    • pp.67-98
    • /
    • 2015
  • Numerical prediction of dynamic behavior of fully coupled saturated porous media is of great importance in many engineering problems. Specifically, static and dynamic response of soils - porous media with pores filled with fluid, such as air, water, etc. - can only be modeled properly using fully coupled approaches. Modeling and simulation of static and dynamic behavior of soils require significant Verification and Validation (V&V) procedures in order to build credibility and increase confidence in numerical results. By definition, Verification is essentially a mathematics issue and it provides evidence that the model is solved correctly, while Validation, being a physics issue, provides evidence that the right model is solved. This paper focuses on Verification procedure for fully coupled modeling and simulation of porous media. Therefore, a complete Solution Verification suite has been developed consisting of analytical solutions for both static and dynamic problems of porous media, in time domain. Verification for fully coupled modeling and simulation of porous media has been performed through comparison of the numerical solutions with the analytical ones. Modeling and simulation is based on the so called, u-p-U formulation. Of particular interest are numerical dispersion effects which determine the level of numerical accuracy. These effects are investigated in detail, in an effort to suggest a compromise between numerical error and computational cost.