Patrick H. Oosthuizen^*

Frontiers in Heat and Mass Transfer, Vol.2, No.1, pp. 1-8, 2011, DOI:10.5098/hmt.v2.1.3004

Abstract The convective heat transfer to a window below which is mounted a natural convective heater has been numerically studied. The flow has been assumed to be three-dimensional and steady and to involve regions of laminar and turbulent flow. Fluid properties have been assumed constant except for the density change with temperature which leads to the buoyancy forces. The solution has been obtained using a commercial cfd code. Results have been obtained for a Prandtl number of 0.7. The effects of changes in the flow variables on the window Nusselt number and on the flow and More >

Muhammad M. Rahman^*, Phaninder Injeti

Frontiers in Heat and Mass Transfer, Vol.2, No.1, pp. 1-9, 2011, DOI:10.5098/hmt.v2.1.3003

Abstract This paper presents the effects of protrusions on heat transfer in a microtube and in a two-dimensional microchannel of finite wall thickness. The effects of protrusion shape, size, and number were investigated. Calculations were done for incompressible flow of a Newtonian fluid with developing momentum and thermal boundary layers under uniform and discrete heating conditions. It was found that the local Nusselt number near a protrusion changes significantly with the variations of Reynolds number, height, width, and distance between protrusions, and the distribution of discrete heat sources. The results presented in the paper demonstrate that More >

Zheng Miao^a, Ya-Ling He^a,*, Tian-Shou Zhao^b, Wen-Quan Tao^a

Frontiers in Heat and Mass Transfer, Vol.2, No.1, pp. 1-10, 2011, DOI:10.5098/hmt.v2.1.3001

Abstract A non-isothermal two-phase mass transport model is developed in this paper to investigate the heat generation and transport phenomena in a direct methanol fuel cell with anisotropic gas diffusion layers (GDLs). Thermal contact resistances at the GDL/CL (catalyst layer) and GDL/Rib interfaces, and the deformation of GDLs are considered together with the inherent anisotropy of the GDL. Latent heat effects due to condensation/evaporation of water and methanol between liquid and gas phases are also taken into account. Formulation of the two-phase mass transport across the membrane electrode assembly (MEA) is mainly based on the classical More >

Morant AE, HD Merchán, EE Lutz

Phyton-International Journal of Experimental Botany, Vol.80, pp. 113-117, 2011, DOI:10.32604/phyton.2011.80.113

Abstract The wheat vernalization response is controlled by three recessive alleles identified and located, that allows to characterize varieties through genetic analysis. However, it is unknown whether the same genetic constitution at a loci scale in different varieties implies the same (1) requirement of cold hours, and (2) interaction with the photoperiod for induction. Therefore, we conducted an experiment with varieties carrying the alleles (vrn-A1, vrn-B1 vrn-D1), extreme condition of vernalization requirements, to compare the duration of the vegetative phase under different photoperiods. The study was conducted in a greenhouse with four varieties of double purpose wheat.… More >

Jurado E¹, M Márquez-Linares², J Flores³

Phyton-International Journal of Experimental Botany, Vol.80, pp. 101-105, 2011, DOI:10.32604/phyton.2011.80.101

Abstract We evaluated the effect of cold storage and fire-related cues on seed germination of Arctostaphylos pungens HBK (Mexican Manzanita), a common shrub in poorly managed pine-oak forests in Durango, Mexico. Because this shrub has a high density in previously burnt forests, we investigated the effect that high temperatures, smoke and charcoal might have on seed germination of this species. Seeds were collected fresh from the shrubs. The highest germination was 30% for seeds that had been cold stored, heat shocked, past through smoke and watered with diluted charcoal. More >

Morant AE, HD Merchán, EE Lutz

Phyton-International Journal of Experimental Botany, Vol.80, pp. 5-8, 2011, DOI:10.32604/phyton.2011.80.005

Abstract This study aimed to characterize wheat cultivars for their chilling requirements for differentiation and their relationship to flowering time, to establish a dual purpose ideotype. Seeds of eight genotypes (cultivars and advanced lines) of bread wheat were exposed to constant temperature (4 °C) in germination chambers for 8, 6, 4 and 2 weeks. A control treatment was kept at room temperature. Four replicates of each treatment were placed in the greenhouse in 250 cc pots containing 4 seedlings each, with irrigation and natural photoperiod, following a randomized complete block design. The greenhouse temperature was constant… More >

K.N. Song¹

Structural Durability & Health Monitoring, Vol.7, No.4, pp. 297-306, 2011, DOI:10.3970/sdhm.2011.007.297

Abstract The IHX (Intermediate Heat Exchanger) of a VHTR (Very High Temperature Reactor) transfers 950° heat generated from the VHTR to a hydrogen production plant. The Korea Atomic Energy Research Institute (KAERI) has manufactured a small-scale prototype of a PCHE (Printed Circuit Heat Exchanger) under consideration as a candidate of the IHX. In this study, as a part of high-temperature structural integrity evaluation of the small-scale PCHE prototype, we carried out a macroscopic structural behavior analysis including structural analysis modeling and thermal/elastic structural analysis under small-scale gas loop test conditions as a precedent study to a More >

Weichung Yeih, Chia-Min Fan, Zen-Chin Chang,Chen-Yu Ku

The International Conference on Computational & Experimental Engineering and Sciences, Vol.20, No.2, pp. 43-44, 2011, DOI:10.3970/icces.2011.020.043

Abstract In this paper, the Cauchy problem of the nonlinear steady-state heat conduction is solved by using the polynomial expansion method and the exponentially convergent scalar homotopy method (ECSHA). The nonlinearity involves the thermal dependent conductivity and mixed boundary conditions having radiation term. Unlike the regular boundary conditions, Cauchy data are given on part of the boundary and a sub-boundary without any information exists in the formulation. We assume that the solution for a two-dimensional problem can be expanded by polynomials as: where T is the temperature distribution, np is the maximum order of polynomial expansion,… More >

Du Chan Kim, Sang Jin Kim, Jung Kwan Seo, Bong Ju Kim, Jeom Kee Paik, Satya N. Atluri

The International Conference on Computational & Experimental Engineering and Sciences, Vol.19, No.3, pp. 67-68, 2011, DOI:10.3970/icces.2011.019.067

Abstract In offshore plant and FPSO topsides, the probability against fire hazard is existed due to complicated processing such as production, storage and offloading oil and gas. High temperature and heat flux from fire accident cause a serious damage on human, environment and primary structures.
The aim of this study is to analyze behaviors and reduction effect of thermal radiation by various heat shields through computational and experimental method.
In this test, flat plate type, corrugated plate type, perforated plate type and wire mesh type heat shield were used. Heat flux and temperature were measured More >

De-Shin Liu, Kuo-Liang Cheng, Zhen-Wei Zhuang, T. C. Lee

The International Conference on Computational & Experimental Engineering and Sciences, Vol.19, No.2, pp. 41-42, 2011, DOI:10.3970/icces.2011.019.041

Abstract High speed spindle is the key component for high precision machine center. The optimum design of spindle cooling system have to achieve to avoid the high heat produce by the build-in motor that can make great damage to the spindle bearing systems. This paper presents a new solid-fluid coupling computing method for design high speed spindle cooling system. Energy equation has been formed for a control volume within the cooling channel to describe the heat absorbing by the coolant moving in a constant speed. Finite different method is applied to solve temperature rising in the More >