Begell House Inc.
Heat Transfer Research
HTR
1064-2285
47
12
2016
JOULE HEATING EFFECTS IN MHD FLOW OF BURGERS' FLUID
1083-1092
Tasawar
Hayat
Department of Mathematics, Quaid-I-Azam University 45320, Islamabad 44000, Pakistan; Nonlinear Analysis and Applied Mathematics (NAAM) Research Group, Faculty of Science,
King Abdulaziz University, P.O. Box 80257, Jeddah 21589, Saudi Arabia
Shafqat
Ali
Faculty of Engineering Sciences, Ghulam Ishaq Khan Institute of Engineering Sciences and Technology, Topi, Pakistan
Muhammad
Awais
Department of Mathematics, COMSATS Institute of Information Technology, Attock 43600, Pakistan
Ahmed
Alsaedi
Nonlinear Analysis and Applied Mathematics (NAAM) Research Group, Department of Mathematics, Faculty of Science, King Abdulaziz University, P. O. Box. 80257,
Jeddah 21589, Saudi Arabia
This article models the problem of two-dimensional magnetohydrodynamic (MHD) boundary layer flow of Burgers'
fluid over a stretching surface with Joule heating. Series solutions are generated after transforming the governing
equations through dimensionless variables. The series solutions are dependent on the auxiliary parameters controlling the convergence analysis. To interpret the obtained solutions, the results of velocity, temperature, and of the local Nusselt number are included for different pertinent parameters.
ACTIVE COOLING PERFORMANCE OF ALL-COMPOSITE LATTICE TRUSS CORE SANDWICH STRUCTURE
1093-1108
Liang
Gao
Key Laboratory of Advanced Structural Materials, Ministry of Education, Changchun University of Technology, Changchun 130012, PR China
Yuguo
Sun
Center for Composite Materials and Structures, Harbin Institute of Technology, Harbin 150001, PR China
Lixin
Cong
Center for Composite Materials and Structures, Harbin Institute of Technology, Harbin 150001, PR China
A theoretical and numerical study of fluid flow and heat transfer characteristics of an all-composite lattice truss core sandwich structure with a constant localized internal heat source under forced water convection is presented. The local fluid characteristics and the mechanism of active cooling are explored by a velocity field analysis. Further, based on the temperature field analysis, the responses of the structural maximum temperature to flow velocity and heat flux are revealed. Three dimensionless parameters scaled by the structural channel height are used to characterize and assess the active cooling performance of the structure. In comparison with numerous heat dissipation media, the result shows that the ultralightweight all-composite lattice truss core sandwich structure has an excellent comprehensive active cooling performance.
INFLUENCE OF VAPOR BUBBLES ON THE THERMAL PERFORMANCE OF A TWO-PHASE CLOSED THERMOSYPHON LOOP WITH A LIQUID HEAT TRANSFER AGENT
1109-1120
Lingjiao
Wei
Institute of Engineering Thermophysics, Chinese Academy of Sciences, Beĳing 100190, China; University of Chinese Academy of Sciences, Beĳing 100049, China
Dazhong
Yuan
Institute of Engineering Thermophysics, Chinese Academy of Sciences, Beĳing 100190, China
Chaohong
Guo
Institute of Engineering Thermophysics, Chinese Academy of Sciences, Beĳing 100190, China
Dawei
Tang
Institute of Engineering Thermophysics, Chinese Academy of Sciences, 11 Beisihuanxi Road, Beijing 100190, China
In this paper, an experimental investigation on the thermal performance of a two-phase closed thermosyphon loop with
a liquid heat transfer agent (TPCTLL) is considered for the first time. TPCTLLs have shown interesting heat transfer
characteristics, though it has not attracted very much attention from researchers. In this work, repetitive experiments were conducted on the designed closed thermosyphon loop with a filling ratio of 95% and with the focus on the heat transfer performance along with increasing heat input. The experimental results of the TPCTLL reveal three types of heat transfer phenomena, including natural convection around the heating section at low heating power, quasisteady-state flow with periodic fluctuations at a medium heating power, and stable flow with consecutively generated vapor bubbles at a high heating power. In addition, an experiment on the thermal performance of a SPCTL is conducted for comparison purposes.
The analysis indicates that the stable and outstanding operation of the TPCTLL appears at high input heat which exceeds the heat transfer limitation of the SPCTL with the same structure and working fluid, and the heat transfer coefficient of the TPCTLL becomes higher than that of the SPCTL.
HEAT TRANSFER FLOW OF A FOURTH-GRADE FLUID IN A NON-DARCY POROUS MEDIUM WITH THERMOPHYSICAL EFFECTS
1121-1139
Mohammed
Abdulhameed
Center for Research in Computational Mathematics, Faculty of Science, Technology and Human Development, Universiti Tun Hussein Onn, 86400 Batu Pahat, Johor DT, Malaysia
Mahathir
Mohamad
Center for Research in Computational Mathematics, Faculty of Science, Technology and Human Development, Universiti Tun Hussein Onn, 86400 Batu Pahat, Johor DT, Malaysia
Ishak
Hashim
School of Mathematical Sciences & Solar Energy Research Institute, Faculty of Science
& Technology, Universiti Kebangsaan Malaysia 43600 UKM Bangi, Selangor DE, Malaysia
Rozaini
Roslan
Center for Research in Computational Mathematics, Faculty of Science, Technology and Human Development, Universiti Tun Hussein Onn, 86400 Batu Pahat, Johor DT, Malaysia
An optimal homotopy asymptotic modeling for a fourth-grade viscoelastic fluid with thermophysical effects baked into a Forchheimer porous medium is presented. The series solution for both the fluid velocity and temperature distributions are developed and the recurrence relations are given explicitly. The effects of Darcy–Forchheimer parameters on skin friction as well as the Nusselt number are discussed. The results reveal that the proposed modeling is effective and easy to apply for a strongly nonlinear system in a boundary-layer problem.
ON HEAT CONDUCTION PROBLEMS IN A COMPOSITE HALF-SPACE WITH A NONHOMOGENEOUS COATING
1141-1155
Stanislaw
Matysiak
Institute of Hydrogeology and Engineering Geology, Faculty of Geology, University of Warsaw, Al. Zwirki i Wigury 93, 02-089 Warsaw, Poland
Dariusz
Perkowski
Faculty of Mechanical Engineering, Biatystok University of Technology, ul. Wiejska 45C, 15-351 Biatystok, Poland
The paper deals with the problems of heat conduction in a functionally graded material (FGM) layer with the heat conductivity coefficient dependent on the depth from the boundary surface as a power function which is ideally bounded by a layered half-space of microperiodic structure. The boundary plane has a given temperature (a) or is heated by a given heat flux (b). The influence of heat conductivity and geometrical properties of the FGM layer and composite material on temperature and heat flux distributions in the considered bodies were investigated.
DEPENDENCE OF WATER TEMPERATURE GRADIENT ON CONDENSATION IN STRATIFIED TWO-PHASE FLOW
1157-1168
Darius
Laurinavicius
Lithuanian Energy Institute, 3 Breslaujos g., Kaunas, LITHUANIA, LT-44403
Marijus
Seporaitis
Lithuanian Energy Institute, 3 Breslaujos g., Kaunas, LITHUANIA, LT-44403
Stasys
Gasiunas
Lithuanian Energy Institute, 3 Breslaujos str., LT-3035 Kaunas, Lithuania
Mindaugas
Valincius
Lithuanian Energy Institute, 3 Breslaujos str., LT-3035 Kaunas, Lithuania
The dependence of water behavior on condensing steam was examined in stratified cocurrent two-phase flow in a relatively short and narrow horizontal rectangular channel. The main scope of investigation was the process of heat removal from the horizontal water surface to the bulk. A high resolution IR measurement technique was employed to measure the water temperature field. Experiments were conducted at different inflow velocities of steam (6, 8, 10, and 12 m/s) and water (0.014, 0.028, 0.042, and 0.056 m/s). The data analysis was performed by comparing calculated vertical thermal gradients of water, bulk heating power distribution, density of steam condensation mass flux, and a modified Jacob criterion. The
results showed very strong dependence of condensation on the steam velocity. The optimal condensation regime was found at a steam-to-water velocity ratio of 300–400.
EXERGY TRANSFER RESEARCH ON THE SANDIA FLAME D − A TURBULENT PILOTED METHANE − AIR JET FLAME
1169-1186
Yaning
Zhang
School of Energy Science and Engineering, Harbin Institute of Technology, Harbin, 150001, China;
Department of Bioproducts and Biosystems Engineering, University of Minnesota, St. Paul, 55108, USA
Xiangyu
Yu
School of Energy Science and Engineering, Harbin Institute of Technology, Harbin, China
Bingxi
Li
School of Energy Science and Engineering, Harbin Institute of Technology, Harbin 150000, Heilongjiang, China
The Sandia Flame D is a typical and popular turbulent piloted nonpremixed methane-air jet flame. It is extensively studied through both experiments and simulations, however, no exergy analysis of the Sandia Flame D has been reported. This study reports the exergy transfer of the Sandia Flame D for the first time by demonstrating the local kinetic, chemical, thermal, and total exergy of gas in the computational domain. The results obtained from this study show that the local kinetic, chemical, thermal, and total exergy values vary in the ranges of 0.0003–1.974, 1.734–8032.531, 0.003–1568.504, and 1.791–8034.545 kJ/kg, respectively. Both the local kinetic and chemical exergy show the highest values near the gas inlet, and they diffuse and diminish in both the axial and radial directions whereas the local thermal exergy has higher values around the flame marginal and lower values beyond. When the combustion of methane goes on, the chemical exergy transfers to the thermal exergy and it consequently reduces monotonically, whereas the thermal exergy increases first and then diminishes, these collectively making the total exergy reduce monotonically on the whole. The results obtained from this study illustrate well what the local exergy characteristics of the Sandia Flame D are as well as how the exergy transfers and loses.
Index Volume 47, 2016
1187-1195