Aravind Sathyanarayana^a, Pramod Warrier^b, Yogendra Joshi^a,*, Amyn Teja^b

Frontiers in Heat and Mass Transfer, Vol.2, No.4, pp. 1-7, 2011, DOI:10.5098/hmt.v2.4.3007

Abstract Electrical and chemical compatibility requirements of electronic components pose significant constraints on the choice of liquid coolants. Dielectric coolants such as Novec fluids and fluoroinerts are plagued by poor thermal properties. This necessitates the development of new heat transfer fluids. In this study we examine mixture formulations that provide an avenue for enhancing the properties of existing heat transfer fluids. Mixture formulations of Novec fluid (HFE 7200) with Methanol and Ethoxybutane are considered. Pool boiling experiments are performed on a copper nanowire surface. The results show an improvement of 24% and 11% in the CHF More >

A. Valan Arasu^a,*, Agus P. Sasmito^b,†, Arun S. Mujumdar^b

Frontiers in Heat and Mass Transfer, Vol.2, No.4, pp. 1-7, 2011, DOI:10.5098/hmt.v2.4.3005

Abstract The heat transfer enhancement of paraffin wax, a cheap and widely used latent heat thermal energy storage material, using nanoparticles is investigated. The effects of nanoparticle volume fraction on both the melting and solidification rates of paraffin wax are analysed and compared for Al₂O₃ and CuO nanoparticles. Present results show that dispersing nanoparticles in smaller volumetric fractions increase the heat transfer rate. The enhancement in thermal performance of paraffin wax is greater for Al₂O₃ compared with that for CuO nanoparticles. More >

D. S. Martínez^†, J. P. Solano, J. Pérez, A. Viedma

Frontiers in Heat and Mass Transfer, Vol.2, No.3, pp. 1-10, 2011, DOI:10.5098/hmt.v2.3.3002

Abstract Non-Newtonian flow and heat transfer in tubes of heat exchangers with reciprocating insert devices have been numerically investigated. The heat exchanger is mechanically assisted by a reciprocating cylinder, which moves the scraping rods inserted in the tubes. An array of semi-circular elements is mounted on each rod, with a pitch p=5D. These elements fit the internal diameter of the tubes. During the reciprocating motion, they scrape the inner tube wall, avoiding fouling. Additionally, the movement of the inserted device generates macroscopic displacements of the flow, which continuously mix core regions with peripheral flow. A power More >

Oronzio Manca^*, Sergio Nardini, Daniele Ricci

Frontiers in Heat and Mass Transfer, Vol.2, No.1, pp. 1-8, 2011, DOI:10.5098/hmt.v2.1.3007

Abstract Convective heat transfer may be enhanced passively by adopting rough surfaces. Ribs break the laminar sub-layer and create local turbulence in the channel, reducing thermal resistance and enhancing the heat transfer. However, higher losses are expected. In this paper a numerical investigation is carried out on air forced convection in a rectangular ribbed channel. A three-dimensional model is developed to study the effect of the angle between the fluid flow direction and the ribbed surface, provided with rectangular turbulators, in the turbulent flow. Simulations s that Nusselt numbers as well as the pressure drops increase More >

Sangoju Bhaskar¹, Ravindra Gettu², B.H. Bharatkumar¹, M. Neelamegam¹

Structural Durability & Health Monitoring, Vol.7, No.4, pp. 231-252, 2011, DOI:10.3970/sdhm.2011.007.231

Abstract The durability of reinforced concrete (RC) exposed to severe environments depends largely on its ability to resist the penetration of aggressive compounds. This paper deals with the corrosion of reinforcement bars (rebars) in cracked concrete exposed to chlorides. A simple U-shaped specimen was used in the study, with a high yield strength deformed bar of 12 mm diameter placed at with 20 mm clear cover. Concrete specimens with three water to cement ratios (w/c) and pre-cracks exposed to chlorides were studied for quality assessment and quantifying the corrosion damage in terms of gravimetric weight loss. More >

Hyung-Jo Jung, Jong-Jae Lee, Jeong-Su Park

The International Conference on Computational & Experimental Engineering and Sciences, Vol.19, No.4, pp. 125-126, 2011, DOI:10.3970/icces.2011.019.125

Abstract A vision-based displacement measurement method for structural health monitoring of large-scale infrastructures such as high-rise buildings and long-span bridges is presented. The method uses digital image processing techniques including a target recognition algorithm, projection of the captured image, and calculation of the actual displacement using target geometry and the number of pixels moved. To measure the displacement of a flexible structure from a distant location which can be regarded as a fixed reference point, a novel image processing method has been devised by means of successive estimation of relative displacement and rotational angle using a More >

Guo Baoqiao, Chen Pengwan, Zhang Qingming, Li Yanjie, Xie Huimin

The International Conference on Computational & Experimental Engineering and Sciences, Vol.17, No.4, pp. 115-116, 2011, DOI:10.3970/icces.2011.017.115

Abstract Optical full-field measurement methods are now widely applied in various domains. In general, the displacement fields can be directly obtained from the measurement; however in mechanical analysis strain fields are preferred. To extract strain fields from noisy displacement fields is always a challenging topic. In this study, a finite element method for smoothing displacement fields and calculating strain fields is proposed. An experimental test case on a holed aluminum specimen under tension is applied to validate this method. The heterogeneous displacement fields of the area around the hole are measured by the digital image correlation More >

Ping Hu, Yang Xia, Limin Tang

The International Conference on Computational & Experimental Engineering and Sciences, Vol.17, No.3, pp. 75-76, 2011, DOI:10.3970/icces.2011.017.075

Abstract In this paper, a modified paradigm of quasi conforming finite element method with truncated polynomial expansions of in-domain displacements and derived expansions of strains is introduced. The purpose is to improve the drawbacks of the traditional one that neglecting the connections between the components of strain and lack of principle in the process of choosing polynomial expansions. Based on the modified framework a four-node quadrilateral flat shell element with complete quadratic polynomials for membrane and bending displacement fields is developed. Numerical tests are carried out for validation of the present element. The results show that More >

Yongzheng Ma, Hong Zheng

The International Conference on Computational & Experimental Engineering and Sciences, Vol.19, No.1, pp. 7-8, 2011, DOI:10.3970/icces.2011.019.007

Abstract The traditional Discontinuous Deformation Analysis (DDA) method, like other Discrete Element Methods, is created to model the discrete block system. The extended DDA method based on meshless interpolations means utilizing meshless interpolations, usually the Moving Least-Squares interpolations, to present block displacement field. In the new extensions here, the effects of earthquake, excavation and bolt reinforcement on the assemblages of large blocks are modeled: for modeling earthquake, the initial acceleration value from earthquake at certain DDA time step can be interpolated from the earthquake acceleration vs. time curve; the modeling of excavation is by reversing in-situ More >

K.C. Chuang, C.C. Ma, C.H. Wang

The International Conference on Computational & Experimental Engineering and Sciences, Vol.19, No.1, pp. 1-2, 2011, DOI:10.3970/icces.2011.019.001

Abstract Smart flexible structures involve four key elements: actuators, sensors, control strategies, and power conditioning electronics, which makes the structures being capable of realizing specific functions. Recently, fiber Bragg grating (FBG) strain sensors are being considered to be integrated into smart structures since they possess many excellent properties such as low density, small size, simplicity of fabrication, and immunity to electromagnetic fields. In this paper, unlike traditional FBG strain sensors, a fiber Bragg grating (FBG) sensing system which has the ability to detect point-wise out-of-plane displacement responses is set up on a smart cantilever beam to… More >