The Experts below are selected from a list of 300 Experts worldwide ranked by ideXlab platform
Ibrahim Dincer - One of the best experts on this subject based on the ideXlab platform.
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estimation of Dimensionless Temperature distributions in spherical products during hydrocooling
International Communications in Heat and Mass Transfer, 1995Co-Authors: Ibrahim DincerAbstract:Abstract Experiments and computations were performed for Temperature distributions within a single spherical product cooled in water flow. Experimental center, half radius and surface Temperature distributions of the individual tomatoes during cooling at a water Temperature of 1°C and a flow velocity of 0.05 m/s were measured. The heat transfer coefficients determined by Dincer model for a single product were used in the computations. Comparisons between experimental results and theoretical predictions were observed in a very good agreement form.
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Transient Temperature distributions in spherical and cylindrical food products subjected to hydrocooling
International Journal of Energy Research, 1994Co-Authors: Ibrahim DincerAbstract:Analytical models were proposed to estimate the Dimensionless Temperature distributions of spherically and cylindrically shaped objects during cooling. In order to test the analytical model, an experimental investigation was carried out to measure Temperatures at the centre, half radius and surface positions of the spherical and cylindrical products (pears and eggplants) subjected to hydrocooling. The measured Temperature distributions were compared with the computed Temperature distributions and very good agreement was observed.
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Determination of Temperature distributions and heat transfer rates during precooling of spherical foodstuffs
International Communications in Heat and Mass Transfer, 1992Co-Authors: Ibrahim DincerAbstract:Abstract This paper presents both the experimental and theoretical results on the Temperature distribution and heat transfer rate during hydrocooling, a precooling method, of tomatoes as spherical products. Temperature values measured at the center and mass-average of the products were converted to the Dimensionless form to obtain the Dimensionless Temperature distributions and variations of heat transfer rate. The theoretical Dimensionless Temperature values and heat transfer rates were computed with a mathematical model using the method of separation of variables according to the boundary condition of third kind in the transient heat transfer, due to the Biot number lies between 0 and 100. These measured and computed Dimensionless Temperature distributions and heat transfer rates were compared and a good agreement was found.
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Methodology to determine Temperature distributions in cylindrical products exposed to hydrocooling
International Communications in Heat and Mass Transfer, 1992Co-Authors: Ibrahim DincerAbstract:Abstract A heat transfer analysis for determination of the Temperature distributions during hydrocooling experiments of cylindrical products is presented. Experimentally determined Dimensionless Temperature values of cylindrical products at water Temperature of 1°C for three cases, namely center, half radius, and surface are presented in graphical form and compared with the theoretical Dimensionless Temperature results computed from the boundary condition of the third kind in the transient heat transfer. In almost all cases examined, typical results indicate that a very good agreement was found between the measurements and predictions.
Qiuwang Wang - One of the best experts on this subject based on the ideXlab platform.
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Optimization of thermal performance in thermocline tank thermal energy storage system with the multilayered PCM(s) for CSP tower plants
Applied Energy, 2019Co-Authors: K.e. Elfeky, N. Ahmed, Xinyi Li, Lin Lu, Qiuwang WangAbstract:Abstract The current paper presents two parametric studies (inverse Stefan number and Dimensionless Temperature difference) to optimize the values of latent heat and melting Temperature of multilayered phase change materials (MLPCM(s)) in thermocline tank for concentrating solar power (CSP) plants. Spherical capsules filled with PCM(s) of different thermo-physical properties are used to fill the bed region, and the molten salt is used as heat transfer fluid (HTF). The numerical model that has been developed uses the Dispersion-Concentric (D-C) equations. By using MATLAB, the governing equations are solved and validated against the experimental results. The results show that in the optimal configuration of the case (B), the values of InvSte number and Dimensionless Temperature (θm) are equal to 1.2 and 0.8 for the top PCM layer, respectively; 0.75 and 0.55 for the middle PCM layer, respectively; and 0.65 and 0.3 for the bottom PCM layer, respectively. Moreover, it is also found that to obtain the best design and distribution of Temperature for a thermocline tank consisting of three layers of PCM, the top PCM layer should melts by ΔT = 55.4 °C below the HTF charging inlet Temperature, the PCM layer at the bottom should solidifies by ΔT = 83.1 °C above HTF discharging inlet Temperature.
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Numerical investigation of the melting Temperature effect on the performance of thermocline thermal energy storage tank for CSP
Energy Procedia, 2019Co-Authors: K.e. Elfeky, N. Ahmed, S.m.a. Naqvi, Qiuwang WangAbstract:Abstract The current paper presents parametric study to evaluate the effect of the melting Temperature on the performance of multi-layered solid-PCM (MLSPCM) thermocline tank for concentrated solar power plants (CSP) applications. The model is developed using the Concentric-Dispersion (C-D) equations. The results obtained are validated against the experimental data from the literature. The governing equations are solved in MATLAB using finite difference method. The results show that an optimal three-layer cascaded thermocline tank should include a top PCM layer that has a Dimensionless Temperature (θ) equal to 0.8, a middle PCM layer that has a Dimensionless Temperature (θ) equal to 0.5, and a bottom PCM layer that has a Dimensionless Temperature (θ) equal to 0.35. Moreover, the results show that an optimal three-layer cascaded latent heat thermocline tank should include a top PCM layer that melts slightly above the molten salt hot supply threshold and a bottom PCM layer that melts slightly below the cold return threshold.
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Characteristics of the Dimensionless Temperature in Tubes With Axial Wall Heat Conduction
Volume 2: Heat Transfer Equipment; Heat Transfer in Multiphase Systems; Heat Transfer Under Extreme Conditions; Nanoscale Transport Phenomena; Theory , 2017Co-Authors: Shicong Li, Xue-fang Xu, Qiuwang WangAbstract:Characteristics of the Dimensionless Temperature, θ, are performed to investigate in laminar circular tube flow by numerical simulation with the presence of axial heat conduction. A uniform heat flux is imposed on outside wall surface. The smallest inner diameter of circular tube is only 200 μm. The heat transfer and flow can be described by traditional Navier-Stokes and energy equations. The results shows that θ is identical under the condition of different specified heat flux on the outside wall surface at the same Peclet number. Furthermore, the Dimensionless Temperature at the tube entrance θ(0) is independent on wall thickness, tube material, working fluid and boundary condition. Hence, the Dimensionless Temperature at the tube entrance θ(0) is only a function of Peclet number and the corresponding correlation of θ(0) in circular tube is obtained from numerical results and validated by other available cases. Moreover, the correlation of θ(0) is also applied with different cross-sectional shapes of heated solid surface when inner diameter of fluid region is not less than 2.0 mm.
Tasawar Hayat - One of the best experts on this subject based on the ideXlab platform.
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analysis of thixotropic nanomaterial in a doubly stratified medium considering magnetic field effects
International Journal of Heat and Mass Transfer, 2016Co-Authors: Tasawar Hayat, Muhammad Waqas, Muhammad Ijaz Khan, A AlsaediAbstract:Abstract Here characteristics of double stratification in magnetohydrodynamic (MHD) boundary layer flow of thixotropic nanofluid in presence of mixed convection are reported. Heat generation/absorption, Brownian motion and thermophoresis effects are also present. Dimensional nonlinear equations are converted into Dimensionless expressions by employing suitable transformations. Homotopic procedure is implemented to solve the governing Dimensionless problems. The variations in Dimensionless Temperature and nanoparticle concentration profiles corresponding to multiple values of physical parameters are shown and analyzed through graphs. Numerical values of local Nusselt and Sherwood numbers are tabulated and interpreted for several values of sundry parameters. It is found that thermal and concentration stratified parameters result in the reduction of Temperature and concentration distributions respectively.
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magnetic field effect in three dimensional flow of an oldroyd b nanofluid over a radiative surface
Journal of Magnetism and Magnetic Materials, 2016Co-Authors: S A Shehzad, Z Abdullah, F M Abbasi, Tasawar Hayat, A AlsaediAbstract:Abstract This article investigates the convective heat and mass conditions in three-dimensional flow of an Oldroyd-B nanofluid. The stretched flow is electrically conducting in the presence of an applied magnetic field. Thermal radiation effects are accounted in the energy equation. The governing nonlinear problems are computed for the convergent approximate solutions. Influences of different parameters on the Dimensionless Temperature and nanoparticle concentration fields are shown and examined. Quantities of physical interest namely local Nusselt and Sherwood numbers are computed and analyzed numerically. Comparison in a limiting case is made with the previous published result and an excellent agreement is noted.
Arshad Khan - One of the best experts on this subject based on the ideXlab platform.
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Unsteady Free Convection Flow of Casson Nanofluid Over a Nonlinear Stretching Sheet
IEEE Access, 2019Co-Authors: Imran Ullah, Muhammad Qasim, Ilyas Khan, Kottakkaran Sooppy Nisar, Sharidan Shafie, Arshad KhanAbstract:In this work, the buoyancy-driven unsteady flow of Casson nanofluid is analyzed. The effects of Brownian motion and thermophoresis on the flow fields are studied in the presence of magnetic field. Moreover, the convective boundary conditions on Temperature and concentration walls are also considered. The similarity solutions are obtained numerically through Keller-box scheme. The accuracy of numerical results is verified via comparison with the results of accessible literature. Investigations perceived that the Dimensionless Temperature is not much affected with Brownian motion and thermophoretic parameters, whereas the impact of both parameters is noted stronger on nanoparticles concentration. The velocity field is observed more pronounced with the strength of magnetic parameter. Also, the influence of Casson fluid parameter on velocity and nanoparticle concentration is noticed opposite. The influence of magnetic parameter on velocity and Temperature is seen more pronounced as compared to nanoparticle concentration. Further, the impact of Biot number on Dimensionless Temperature and nanoparticles concentration is found identical for both steady and unsteady flows. A reduction in velocity field is also observed with increment in slip parameter.
A Alsaedi - One of the best experts on this subject based on the ideXlab platform.
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analysis of thixotropic nanomaterial in a doubly stratified medium considering magnetic field effects
International Journal of Heat and Mass Transfer, 2016Co-Authors: Tasawar Hayat, Muhammad Waqas, Muhammad Ijaz Khan, A AlsaediAbstract:Abstract Here characteristics of double stratification in magnetohydrodynamic (MHD) boundary layer flow of thixotropic nanofluid in presence of mixed convection are reported. Heat generation/absorption, Brownian motion and thermophoresis effects are also present. Dimensional nonlinear equations are converted into Dimensionless expressions by employing suitable transformations. Homotopic procedure is implemented to solve the governing Dimensionless problems. The variations in Dimensionless Temperature and nanoparticle concentration profiles corresponding to multiple values of physical parameters are shown and analyzed through graphs. Numerical values of local Nusselt and Sherwood numbers are tabulated and interpreted for several values of sundry parameters. It is found that thermal and concentration stratified parameters result in the reduction of Temperature and concentration distributions respectively.
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magnetic field effect in three dimensional flow of an oldroyd b nanofluid over a radiative surface
Journal of Magnetism and Magnetic Materials, 2016Co-Authors: S A Shehzad, Z Abdullah, F M Abbasi, Tasawar Hayat, A AlsaediAbstract:Abstract This article investigates the convective heat and mass conditions in three-dimensional flow of an Oldroyd-B nanofluid. The stretched flow is electrically conducting in the presence of an applied magnetic field. Thermal radiation effects are accounted in the energy equation. The governing nonlinear problems are computed for the convergent approximate solutions. Influences of different parameters on the Dimensionless Temperature and nanoparticle concentration fields are shown and examined. Quantities of physical interest namely local Nusselt and Sherwood numbers are computed and analyzed numerically. Comparison in a limiting case is made with the previous published result and an excellent agreement is noted.