An unsaturated flow of moisture in porous hygroscopic media at low moisture contents

Kolhapure, N.H.; Venkatesh, K. V. L.

doi:10.1016/s0009-2509(97)00140-1

Cited by 7 publications

(8 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Hall 1994, Pel 1998). The authors in reference (Kolhapure 1997) also consider a correction due to the liquid phase activity in equation 2, which could be used to model the effect of ionic species in dissolved in the pore solution. This term is neglected in the present model.…”

Section: Liquid Phase Transportmentioning

confidence: 99%

Modeling the effect of a hydrophobic concrete admixture on chloride ingress : contractor's supplemental report for CPC Project F09-AR05A

Samson¹,

Tie-wei²

2018

View full text Add to dashboard Cite

show abstract

Section: Liquid Phase Transportmentioning

confidence: 99%

Modeling the effect of a hydrophobic concrete admixture on chloride ingress : contractor's supplemental report for CPC Project F09-AR05A

Samson¹,

Tie-wei²

2018

View full text Add to dashboard Cite

show abstract

“…The activation energy variation in set cement paste and potato were presented respectively in the works [21,26]. The superficial moisture activation energy was considered there as a sum of free water activation energy and binding energy of water with a matrix.…”

Section: Effective Diffusivitymentioning

confidence: 99%

“…The problem of superficial diffusion was discussed among other things in the works [15,[17][18][19][20][21]26]. In the work [17] this kind of diffusion was analysed in the case of deep drying in fine-porous media.…”

Section: Introductionmentioning

confidence: 99%

“…Introducing to them general Fick's and Darcy's laws the authors derived the formulas describing water vapour and superficial moisture diffusion coefficients in the multiphase media. Further in the article [21] based on the approach proposed in [18][19][20] one derived expressions for the moisture diffusion coefficient in a liquid and gaseous phase in the case of non-saturated porous medium. Then one determined a variation of these coefficients and effective moisture diffusion coefficient as humiditydependent functions in the hygroscopic range for potato.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Estimation of moisture superficial diffusivity in porous materials

Świrska-Perkowska

2011

International Journal of Heat and Mass Transfer

View full text Add to dashboard Cite

“…Bound water movement is expressed in terms of the diffusion of sorbed water driven by a gradient in the chemical potential of the sorbed water molecules [2]. This similar approach had been used by Kolhapure and Venkatesh [1] during studies of an unsaturated flow of low moisture for porous hygroscopic media. During low moisture contents, pores mainly consist of bound water and vapour.…”

Section: Introductionmentioning

confidence: 99%

Drying Comparison of Nonhygroscopic and Hygroscopic Materials

Harun

Ong

Ahmad

2013

AMM

View full text Add to dashboard Cite

Abstract. This paper investigates and presents the simulation of drying for hygroscopic and nonhygroscopic materials. This present work used a coupled mathematical model of mass, heat and gas transfer that implemented to finite element method in two dimensional and numerically compute using Skyline solver to capture highly nonlinear transient process. Bound water contribution was taken into account in the drying of hygroscopic materials by incorporating constitutive equation of bound water. The results showed drying process can be divided into three periods named constant rate period (CRP), first falling rate period (FRP1) and second falling rate period (FRP2). Capillary action is dominated during CRP before vapour diffusion takes place in FRP1. Bound water movement is generated by vapour pressure gradient exists that represent hygroscopic material. IntroductionIn reality of porous material consists of three types of water that indentified as free, capillary and bound water. Free water is able to flow under an applied pressure gradient, capillary water is immobile water held by capillary forces in regions of microporosity, i.e. dead-end pores. Meanwhile, bound water includes both the water strongly held to negatively charged particles surfaces and the water of hydration associated with the mineral charge-balancing unit. The difference level of these types of water will exhibit different properties of porous material that generally known as hygroscopic and non hygroscopic materials. Drying of nonhyrosocpic materials only involve free and capillary water that easily experimentally can be determined and measured with specific equipment. In contrast to that, drying of hygroscopic materials not only involves free and capillarity water but also a tightly bound water that strongly attach to the solid matrix up to hydration temperature [1]. Previous studies on drying of hygroscopic and nonhygroscopic have present different equations and formulations as well as the concept that had been derived [1,2,3,4,5]. Bound water movement is expressed in terms of the diffusion of sorbed water driven by a gradient in the chemical potential of the sorbed water molecules [2]. This similar approach had been used by Kolhapure and Venkatesh[1] during studies of an unsaturated flow of low moisture for porous hygroscopic media. During low moisture contents, pores mainly consist of bound water and vapour. Stanish et al [3] in their development had derived a uniquely explicit expression for boundwater flux in terms of temperature and vapor pressure gradients. Meanwhile, Zhang et al [4] and Haghi [5] revealed that the bound water transport mechanism only effective when saturation irreducible is reached. The movement of bound water in hygroscopic materials is also known as liquid moisture transfer near dryness or sorption diffusion with driving force of vapor transport and without liquid transport [6]. Although substantial efforts have been made in the studies of hygroscopic materials, there are limited references available on modeling drying...

show abstract

An unsaturated flow of moisture in porous hygroscopic media at low moisture contents

Cited by 7 publications

References 16 publications

Modeling the effect of a hydrophobic concrete admixture on chloride ingress : contractor's supplemental report for CPC Project F09-AR05A

Modeling the effect of a hydrophobic concrete admixture on chloride ingress : contractor's supplemental report for CPC Project F09-AR05A

Estimation of moisture superficial diffusivity in porous materials

Drying Comparison of Nonhygroscopic and Hygroscopic Materials

Contact Info

Product

Resources

About