International Journal of Application or Innovation in Engineering & Management (IJAIEM) Web Site: www.ijaiem.org Email: editor@ijaiem.org Volume 4, Issue 5, May 2015 ISSN 2319 - 4847 Correction of the Effective Thermal Conductivity of Two Phase System using Resister Model with Cylindrical Inclusions 1 Harish Kumar Sublania ,2K. J. Singh ,3R.Singh 1 Scholor, MGS University of Bikaner (Rajasthan) 2 Govt. College, Suratgarh, Sri Ganganagar (Rajasthan) 3 University of Rajasthan, Jaipur ABSTRACT The study of heat transfer through two phase materials from the values of thermal conductivity of the constituent phases and there volume fractions. The resister model has been applied to determine the effective thermal conductivity (ETC) in this arrangement has been divided in to unit cells, each of which contains a cylinder. The random packing of Phases, non-uniform shape of particles and the flow of the heat flux lines not restricted to be parallel, we replace physical volume fraction of solid phases by porosity correction term F. In this paper, we calcute the effectivity thermal conductivity using a Jagjiwan & Singh model with correction of this model. Comparison of the predicted values of the correlations with experimental results is also made. The predictions of effective thermal condivity of two phase materials match well with the good experimental results. Keywords:-Efective thermal conductivity; Correction term; Unit cell approach; Cylindrical inclusions; Two phase systems. 1.INTRODUCTION The study of thermal parameters of these two phase systems is also valuable for the explosive industry, nuclear reactors and in missile technology. The importance of two phase materials like ceramics, granular materials, emulsions and metal foams like in their applications in high emulsions and metal foam lies in their applications in high performance cryogenic insulations, packed beds, composite materials power generation. In this literature we finds several efforts [49] in which the situation has been simplified by assuming that the particles are of specific shape and arranged in a particular geometries within the continuous phases. A recent advancement in there estimation of the effective thermal conductivity specifically for metallic foam saturated with a fluid utilizing a geometrical estimate was developed by Calmidi and Mahajan [2]and Boomsma and poulikakos [3]. R. Singh & H.S. Kasana [11] independently developed models utilizing geometrical estimate for calculation of ETC for matelic foam saturated with a fluid. In this work, the term simulation is used for a Jagjiwan& R.Singh based particle deposition which created two dimensional structures [18-20]. These simulated structures function as a master for the modeling of the thermal conductivity. The term modeling here, refers to the mathematical description of the thermal conductivity of porous media, predominantly using the resister model. We have tried to fill the space arrangement of cells of equal size with the minimal surface energy and a theoretical model has been proposed to predict ETC of the two phase systems with cylindrical inclusions. 2.THEORY To solve this problem we take there some assumptions: (a) The contact resistance between the fluid and solid phase is negligible, (b) the mixture is homogeneous throughout and no transfer of heat occurs by way of convection or radiation and (c) the heat flows along the x-axis and the flux lines remain parallel during the heat flow. Let the grains of the solid phase be 3-D cubic geometry principal axis 2a, 2c and 2a (a<c) .Suppose the grains located of a simple cube of side 2b each. The distribution of two dimensions is shown in figure 1 (i). The geometry of a unit cell is shown in fig. (ii). Assume that the origin of coordinate axis be located at the center of the 3-D cubic geometry. We have divided the unit cell in to eight parts. This is further sub divided in to rectangular bars shown in figure 1(iv). Length is bar of b, cross section of area is dxdz. The shaded portion of the element represents the solid phase and non shaded portion are fluid phase. Volume 4, Issue 5, May 2015 Page 22 International Journal of Application or Innovation in Engineering & Management (IJAIEM) Web Site: www.ijaiem.org Email: editor@ijaiem.org Volume 4, Issue 5, May 2015 ISSN 2319 - 4847 Fig-1(i-iv). The resister model for two phase systems with cylindrical particles. The volume fraction of the solid phase of the bar w be (cdxdz)/(bdxdz) = c/b (1) Similarly the volume fraction of fluid phase be [(b-c) dxdz]/bdxdz = (1-c/b) (2) The thermal conductivity of bar will be λ’ = λ1(c/b) + λ2(1-c/b) (3) Where λ1 and λ2 are the thermal conductivities of solid and fluid phase respectively. With refrence to the fig 1(iii). From the reference paper of Jagjiwan& R.Singh [20] we find this eqution will be1/λe=[(a/b)/{(λ1-λ2)(πac)}/(4b2)+λ2]+ [(1-a/b)/ λ2 ] (4) Therefore λe = λ2[(λ1-λ2){(πac)/(4b2)} + λ2] / [(1-a/b)( λ1-λ2){( πac ) / (4b2)}] + λ2 (5) The unit cell contains one cylinder that lies inside. Therefore, fractional volume of the solid phase will be Ф1 = πa2c/8b3 (6) If c=b then we get Ф1 = (π/8) (a2/b2) Therefore Eq. 5 & 7 find the following relations For the cubic packing of cylindrical inclusions the maximum value of the packing fraction will be less than 0.785 ( a<b). Then eqn. 8 valid for 0< ф1<0.785.The effective thermal conductivity depends upon various characteristics of the system. We have to modify the expression given in eqn. (8) by change some correction term. Considering random packing of phases, non-uniform shape of particles and the flow of the heat flux lines not restricted to be parallel, we here replace physical volume fraction of solid phase by porosity correction term F. The function F is a physical volume fraction of solid phase and the ratio of the thermal conductivity of the constituent phases. Therefore Eqn. 8 may be written as: Rearranging the Eqn. (9), we get Volume 4, Issue 5, May 2015 Page 23 International Journal of Application or Innovation in Engineering & Management (IJAIEM) Web Site: www.ijaiem.org Email: editor@ijaiem.org Volume 4, Issue 5, May 2015 AF + BF1/2 + C = 0 ISSN 2319 - 4847 (10) Where Result and discussion The theoretical model discussed above on two phase systems, for which the characteristics of the constituent phases, including thermal conductivities of solid phase, fluid phase, porosity and the experimental results for the ETC have been cited in the literature [18-20]. First of all, function F is calculated from a large number of experimental data reported in the literature, by putting the value of thermal conductivity of constituent phases and as in Eq. (9) . A curve has been plotted between F1/2and φ12/3*exp [λ2/(λ1+λ2)] The plot of φ12/3*exp[λ2/(λ1+λ2)] versus F1/2 are shown in fig. 1-2 . It is found that F1/2 (for Solid-air , emulsion, suspension, granular, and solid-solid two phase systems) increases roughly linearly with increasing φ12/3*exp[λ2/(λ1+λ2)] . The linear expression F1/2 = C1φ12/3*exp [λ2/(λ1+λ2)] +C2 (11) Is suggested, C1 and C2 are constant. These constants are calculated for different type of samples and we found that, the values of these constants for Solid-air, emulsion, suspension, granular, and solid-solid two phase systems are 0.83379 and 0.0393 respectively. On putting (8) as the porosity correction term in (11) we have calculated values of effective thermal conductivity for a large number of samples reported in the literature. Tables show a comparison of experimental results of effective thermal conductivity and calculated values from (9). The average deviation is 4.08% for solid-air, emulsion, suspension, granular, and solid-solid two phase systems shown table-1. Table – 1 Comparison of ETC value for two phase system using Eq. (9). The thermal conductivity is in W m-1K-1. Ref.[18-20]. S.N Type of sample φ1 λ1 λ2 λtheo λexp Error 0.012 80.3505085 25 1 Cu/solder 398 78.1 79.8 0.69 4 4 0.013 80.5049783 2 Cu/solder25 398 78.1 80 0.63 6 2 0.050 85.4133555 3 Cu/solder25 398 78.1 85.2 0.25 7 9 0.099 92.5732783 4 Cu/solder25 398 78.1 92.4 0.19 6 8 0.019 81.2649358 5 Cu/solder25 398 78.1 80.8 0.58 5 3 0.026 82.1468155 6 Cu/solder25 398 78.1 81.7 0.55 3 6 0.028 82.4477715 7 Cu/solder25 398 78.1 82 0.55 6 8 0.102 93.0897677 8 Cu/solder25 398 78.1 92.7 0.42 9 6 0.237 118.907894 115. 9 Cu/solder25 398 78.1 3.04 7 1 4 0.084 10 Cu/solder25 398 78.1 90.3117015 90.2 0.12 8 0.158 102.535947 11 Cu/solder25 398 78.1 102 0.53 6 7 0.251 122.237610 12 Cu/solder25 398 78.1 118 3.59 6 1 0.289 132.157780 13 Cu/solder25 398 78.1 125 5.73 4 7 132.607389 14 Cu/solder25 0.291 398 78.1 125 6.09 7 0.61 0.16 0.25701995 0.23 15 cellosize/flexol26 0.3 9.37 6 1 2 5 0.60 0.18 0.23742732 0.26 10.7 16 Water/Oil solvent27 0.2 4 2 2 6 4 0.23650649 0.23 27 17 cellosize/polypropyllene glycol 0.3 0.55 0.15 1.07 9 4 Volume 4, Issue 5, May 2015 Page 24 International Journal of Application or Innovation in Engineering & Management (IJAIEM) Web Site: www.ijaiem.org Email: editor@ijaiem.org Volume 4, Issue 5, May 2015 18 Water/mineral Oil27 0.4 19 Selenium/poly. Glycol29 0.1 20 Water/Oil solvent27 0.2 21 Water/Oil solvent27 0.4 22 Water/mineral Oil27 0.2 23 Water/mineral Oil27 0.4 24 cellosize/polypropyllene glycol26 0.1 25 cellosize/polypropyllene glycol26 0.1 26 cellosize/polypropyllene glycol26 0.1 27 cellosize/polypropyllene glycol26 0.1 28 Lead powder/Si rubberg23 0.05 0.61 1 5.20 8 0.60 5 0.60 7 0.61 1 0.61 1 0.55 1 0.57 7 0.55 1 0.57 7 34.7 2 29 Bi. powder/Si rubberg23 0.05 8.33 30 Bi. powder/Si rubberg23 0.16 8.33 31 Bi. powder/Si rubberg23 0.24 8.33 32 Silica powder/dimethyl vnyle28 0.1 1.68 33 Silica powder/dimethyl vnyle28 0.15 1.68 34 Silica powder/dimethyl vnyle28 0.25 1.68 0.14 9 0.14 0.18 2 0.17 3 0.14 9 0.14 9 0.15 0.15 4 0.15 0.15 4 0.38 5 0.38 5 0.38 5 0.38 5 0.17 6 0.17 4 0.17 4 0.29974871 9 0.19950752 3 0.23750313 7 0.32636385 3 0.20251287 2 0.29974871 9 0.17189389 9 0.17684265 6 0.17189389 9 0.17684265 6 0.49343737 5 0.46312929 1 0.61578663 1 0.76621905 3 0.22315232 1 0.24632654 3 0.31124182 5 Error = 4.08 ISSN 2319 - 4847 0.29 2 0.18 0.26 7 0.31 2 0.23 4 0.29 3 0.18 2 2.65 10.8 4 11.0 5 4.60 13.4 6 2.30 5.55 0.18 1.75 0.18 2 5.55 0.18 1.75 0.46 3 0.43 3 0.59 1 0.73 4 0.23 1 0.25 2 0.29 6.57 6.96 4.19 4.39 3.40 2.25 7.32 Table -2 Comparison of ETC values for two phase systems using Eq. (9) and R.Singh model .The thermal conductivity is in W m-1 K-1. Ref.[18-20]. λth(our J S.N Type of sample φ1 λ1 λ2 λexp Error Error &R.singh model) 25 1 Cu/solder 0.0124 398 78.1 79.8 80.351 0.690 79.731 0.10 2 Cu/solder25 0.0136 398 78.1 80 80.505 0.631 79.952 0.10 3 Cu/solder25 0.0507 398 78.1 85.2 85.413 0.250 86.837 1.90 25 4 Cu/solder 0.0996 398 78.1 92.4 92.573 0.188 95.784 3.60 5 Cu/solder25 0.0195 398 78.1 80.8 81.265 0.575 81.052 0.30 6 Cu/solder25 0.0263 398 78.1 81.7 82.147 0.547 82.325 0.70 7 Cu/solder25 0.0286 398 78.1 82 82.448 0.546 82.754 0.90 8 Cu/solder25 0.1029 398 78.1 92.7 93.090 0.420 96.393 3.90 9 Cu/solder25 0.2377 398 78.1 115.4 118.908 3.040 123.52 7.00 10 Cu/solder25 0.0848 398 78.1 90.2 90.312 0.124 93.67 3.20 11 Cu/solder25 0.1586 398 78.1 102 102.536 0.525 106.969 4.80 25 12 Cu/solder 0.2516 398 78.1 118 122.238 3.591 126.685 7.30 13 Cu/solder25 0.2894 398 78.1 125 132.158 5.726 135.779 8.60 14 Cu/solder25 0.291 398 78.1 125 132.607 6.086 136.181 8.90 15 cellosize/flexol26 0.3 0.616 0.161 0.235 0.257 9.370 0.276 17.60 16 Water/Oil solvent27 0.2 0.604 0.182 0.266 0.237 10.742 0.258 2.80 17 cellosize/polypropyllene 0.3 0.55 0.15 0.234 0.237 1.071 0.256 9.50 Volume 4, Issue 5, May 2015 Page 25 International Journal of Application or Innovation in Engineering & Management (IJAIEM) Web Site: www.ijaiem.org Email: editor@ijaiem.org Volume 4, Issue 5, May 2015 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 glycol27 Water/mineral Oil27 Selenium/poly. Glycol29 Water/Oil solvent27 Water/Oil solvent27 Water/mineral Oil27 Water/mineral Oil27 cellosize/polypropyllene glycol26 cellosize/polypropyllene glycol26 cellosize/polypropyllene glycol26 cellosize/polypropyllene glycol26 Lead powder/Si rubberg23 Bi. powder/Si rubberg23 Bi. powder/Si rubberg23 Bi. powder/Si rubberg23 Silica powder/dimethyl vnyle28 Silica powder/dimethyl vnyle28 Silica powder/dimethyl vnyle28 ISSN 2319 - 4847 0.4 0.1 0.2 0.4 0.2 0.4 0.611 5.208 0.605 0.607 0.611 0.611 0.149 0.14 0.182 0.173 0.149 0.149 0.292 0.18 0.267 0.312 0.234 0.293 0.300 0.200 0.238 0.326 0.203 0.300 2.654 10.838 11.048 4.604 13.456 2.303 0.311 0.189 0.258 0.354 0.215 0.311 6.60 5.30 3.20 13.40 7.70 6.20 0.1 0.551 0.15 0.182 0.172 5.553 0.198 4.40 0.1 0.577 0.154 0.18 0.177 1.754 0.225 7.50 0.1 0.551 0.15 0.182 0.172 5.553 0.18 0.80 0.1 0.577 0.154 0.18 0.177 1.754 0.185 3.00 0.05 0.05 0.16 0.24 0.1 0.15 0.25 34.72 8.33 8.33 8.33 1.68 1.68 1.68 0.385 0.385 0.385 0.385 0.176 0.174 0.174 0.463 0.433 0.591 0.734 0.231 0.252 0.29 0.493 6.574 0.463 6.958 0.616 4.194 0.766 4.390 0.223 3.397 0.246 2.251 0.311 7.325 Error = 4.08 0.467 0.90 0.452 4.40 0.582 1.50 0.683 6.80 0.224 2.80 0.245 2.40 0.248 2.90 Error = 4.735 Fig. 2- Variation of porosity correction term and φ12/3*exp[λ2/(λ1+λ2)]. Fig. 3 comparison between experimental, theoretical and J.& R.Singh (model) values of ETC of the sample no. 1-14. Volume 4, Issue 5, May 2015 Page 26 International Journal of Application or Innovation in Engineering & Management (IJAIEM) Web Site: www.ijaiem.org Email: editor@ijaiem.org Volume 4, Issue 5, May 2015 ISSN 2319 - 4847 Fig. 4 comparison between experimental, theoretical and J.& R.Singh (model) values of ETC of the sample no. 15-34. 4. CONCLUSIONS We have observed from these figures that for our model the average percentage deviation are better than others models. The empirical model proposed here is capable of predicting effective thermal conductivities close to the experimental values even for mixtures of higher conductivity ratio and high porosities; whereas one may find that other models give higher deviations in those situations. This model simple but powerful enough without compromising on the results. This clearly indicates that the slope of the curve as shown in fig. (1) Strongly depends on the ratio of thermal conductivity of the constituent phases. The correlation presented here showed that the effective thermal conductivity strongly depends on the ratio of thermal conductivity of the constituents. Other factors have small effect on the ETC. The parameters of fluid, such as the size, volume fraction, the thickness of the interfacial layer, are shown to play important roles in the enhancement of thermal conductivity. The model predictions have been shown to be reasonable and are in good agreement with the available experimental data. It is expected that the experimentally validated model will be helpful in the evaluation of the effective thermal conductivity for foam like materials in the whole range of porosity. This method was therefore adopted to measure and discuss thermal conductivity in the succeeding studies. Acknowledgements:-The authors would like to thank Dr.Kamaljeet Singh for critical comments and helpful discussion. REFERENCES [1]. L.S. Verma, A.K. Shrotriya, R. Singh, D.R. Chaudhary, Thermal conduction in two phase materials with spherical and non-spherical inclusions, J. Phys. D.: Appl. Phys. 24 (1991) 1729–1737. [2]. V.V. Calmidi, R.L. Mahajan, The effective thermal conductivity of high porosity Fibrous metal foams, ASME J. Heat Transfer 121 (1999) 466–471. [3]. K. Boomsma, D. Poulikakos, on the effective thermal conductivity of a three Dimensionally structured fluid saturated metal foams, Int. J. Heat Mass Transfer 44 (2001) 827–836. [4]. V.V. Calmidi, Transport phenomena in high porosity metal foams, Ph.D. thesis, University of Colorado, Boulder,CO, 1998. [5]. C.T. Hsu, P. Cheng, K.W. Wong, A lumped parameter model for stagnant thermal Conductivity of spatially periodic porous media, ASME J. Heat Transfer 117 (1995) 264–269. [6]. R.W. Zimmerman, Compressibility of Sandstones, Elsevier Science Publisher Co., NewYork, 1991. [7]. V.V. Calmidi, Transport Phenomena in High Porosity Metal Foams .Ph.D. Thesis University of Colorado, Boulder, CO, 1998. [8]. A.A. Babanov, Method of calculation of thermal conduction coefficient of capillary Porous material, Sov. Phys. Tech. Phys. 2(1957) 476–484. [9]. A.D. Brailsford, K.G. Major, The thermal conduction of aggregates of several phases including porous materials, Br. J. Appl. Phys. 15 (1964) 313–319. [10]. G.R. Hadley, Thermal conductivity of packed metal powders, Int. J. Heat Mass Transfer 29 (1986) 909–920. [11]. R. Singh, H.S. Kasana, Computational aspects of effective thermal conductivity of highly porous metal foams, Appl. Therm. Eng. 24 (13) (2004) 1841–1849. Volume 4, Issue 5, May 2015 Page 27 International Journal of Application or Innovation in Engineering & Management (IJAIEM) Web Site: www.ijaiem.org Email: editor@ijaiem.org Volume 4, Issue 5, May 2015 ISSN 2319 - 4847 [12]. A. Bhattacharya, V.V. Calmidi, R.L. Mahajan, Thermo physical properties of high porosity metal foams, Int. J. Heat Mass Transfer 45 (2002) 1017–1031. [13]. Leong K C, Yang C and Murshed S M S 2006 A model for the thermal conductivity of nanofluids—the effect of interfacial layer J. Nanopart. Res. 8 245. [14]. A.D. Sullins, K. Daryabeigi, Effective thermal conductivity of high porosity open cell nickel foam, in: 35thAIAA Thermo-Physics Conference, AIAA-2001-2819, Anaheim, CA, 2001. [15]. M. Kaviany, Principles of Heat Transfer in Porous Media, Springer, New York, 1991. [16]. R.Singh, K.J.Singh, D.R.Choudhary, Heat conduction and porosity correction term for diverse two-phase systems, J.Phys.D:Appl. Phys. 28 (1995) 1573-1578. [17]. K.J.Singh, R.Singh, D.R.Choudhary, Heat conduction and porosity correction for spherical and cubic particles in a simple cubic packing, J.Phys.D:Appl. Phys. 31 (1998) 1681-87. [18]. Jagjiwanram& Singh R, Accepted for publication in indain J Eng Mater Sci,(2004). [19]. Jagjiwanram, R. Singh /Applied Engineering 24(2004), 2727-2735. [20]. Jagjiwanram, R. Singh /Indian journal of pure and applied physics vol.42 (2004), 600-609. [21]. H.F. Zhang, X. S. Ge and H. Ye, “ Randomly Mixed Model for Predicting The ETC of Moist Porous Media,” Journal of physics D:Applied physic,Vol. 39, No. 1, 2006, pp.220-226. [22]. Jyoti Rani, K.J.Singh, and R.Singh.“The effect of interfacial layer on the ETC of porous metal foam,” 2013. [23]. K.J Singh, R.Singh, and D.R.Chaudhary, “Heat conduction and porosity correction in body centered cubic packing of three phase system” Ind.jour.of pure and applied physics Vol.37, 1999,pp.8-12. [24]. K.J Singh, R.Singh, and D.R.Chaudhary, “Heat conduction in two phase systems of randomly dispersed particles” J. of energy Heat transfer, Vol.20, 51-58 (1998). [25]. D.R.Chaudhary, R.Singh, A.K. Shrotriya, K.J Singh and K.Mishra“Measurement of Heat storage coefficient of some building materials at different interstitial air pressures” on energy conservation in buildings. Nov,12-14, 1992,Roorkee. [26]. N. Pan, W. Zhong, Fluid Transport Phenomena in Fibrous Materials, Woodhead Publishing Ltd., Cambridge, UK, 2006. Volume 4, Issue 5, May 2015 Page 28