scholarly journals Flow and Heat Transfer Property of Oldroyd-B-Fluid-Based Nanofluids Containing Cylindrical Particles in a Pipe

Processes ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 647
Author(s):  
Wenqian Lin ◽  
Peijie Zhang ◽  
Jianzhong Lin
Keyword(s):  
Heat Transfer ◽  
Circular Cross Section ◽  
Energy Performance ◽  
Weissenberg Number ◽  
Particle Orientation ◽  
Particle Volume ◽  
Transfer Property ◽  
Flow And Heat Transfer ◽  
Heat Transfer Property ◽  
Cylindrical Particles

Flow and heat transfer property of Oldroyd-B-fluid-based nanofluids containing cylindrical particles are studied in a pipe with circular cross-section in the range of Reynolds number (Re) from 100 to 2000, Weissenberg number (We) from 0.1 to 2, particle aspect ratio (β) from 2 to 16 and particle volume concentration (Φ) from 0.1% to 2.5%. The motion equation of Oldroyd-B fluid with particles, the equation for probability density function of particle orientation and convection-diffusion equation for particles are solved numerically. The numerical method used in the simulation is validated by comparing with the available results. The effects of Re, We, β and Φ on the friction factor (f), Nusselt number (Nu) and ratio of energy performance evaluation criterion (PECt/PECf) for Oldroyd-B-fluid-based nanofluids to that for Oldroyd-B fluids are discussed. The results showed that the values of f and Nu of Oldroyd-B-fluid-based nanofluids are larger than that of water-based nanofluids and that of pure Oldroyd-B fluids. The values of f increase with increasing Re, We and Φ, but with decreasing β. The values of Nu and PECt/PECf are enhanced with increasing Re, We, β and Φ. The increase of f is larger than that of Nu at lower Re, but is less than that of Nu at higher Re. It is more effective to use Oldroyd-B-fluid-based nanofluids with cylindrical nanoparticles to improve the heat transfer at the conditions of higher Re, We, β and Φ. Finally, the correlation formula of PECt/PECf as a function of Re, We, β and Φ is derived.

Numerical study of fluid dynamics and heat transfer property of dual fluidized bed gasifier

Energy ◽  
2021 ◽  
pp. 121246
Author(s):  
Feihu Fan ◽  
Min Zheng ◽  
Shiliang Yang ◽  
Hua Wang
Keyword(s):  
Heat Transfer ◽  
Fluid Dynamics ◽  
Fluidized Bed ◽  
Numerical Study ◽  
Transfer Property ◽  
Heat Transfer Property ◽  
Dual Fluidized Bed ◽  
Fluidized Bed Gasifier

scholarly journals Heat Transfer Study of the Ferrofluid Flow in a Vertical Annular Cylindrical Duct under the Influence of a Transverse Magnetic Field

Fluids ◽  
2021 ◽  
Vol 6 (3) ◽  
pp. 120
Author(s):  
Panteleimon Bakalis ◽  
Polycarpos Papadopoulos ◽  
Panayiotis Vafeas
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Field Strength ◽  
Circular Cross Section ◽  
Transverse Magnetic ◽  
Uniform Grid ◽  
Volumetric Concentration ◽  
Flow And Heat Transfer ◽  
Axial Pressure Gradient ◽  
Transfer Study

We studied the laminar fully developed ferrofluid flow and heat transfer phenomena of an otherwise magnetic fluid into a vertical annular duct of circular cross-section and uniform temperatures on walls which were subjected to a transverse external magnetic field. A computational algorithm was used, which coupled the continuity, momentum, energy, magnetization and Maxwell’s equations, accompanied by the appropriate conditions, using the continuity–vorticity–pressure (C.V.P.) method and a non-uniform grid. The results were obtained for different values of field strength and particles’ volumetric concentration, wherein the effects of the magnetic field on the ferrofluid flow and the temperature are revealed. It is shown that the axial velocity distribution is highly affected by the field strength and the volumetric concentration, the axial pressure gradient depends almost linearly on the field strength, while the heat transfer significantly increases due to the generated secondary flow.

scholarly journals Preparation of Hollow Silica by Spray Drying of Nano Silica Particles and Its Heat Transfer Property

2012 ◽  
Vol 22 (10) ◽  
pp. 531-538 ◽  
Author(s):  
Chan Ki Youn ◽  
Hyung Mi Lim ◽  
Sujin Cha ◽  
Dae Sung Kim ◽  
Seung-Ho Lee
Keyword(s):  
Heat Transfer ◽  
Spray Drying ◽  
Silica Particles ◽  
Nano Silica ◽  
Transfer Property ◽  
Hollow Silica ◽  
Heat Transfer Property

scholarly journals A Computational Visualization of Three Dimensional Flow: Finding Optimum Heat Transfer and Pressure Drop Characteristics From Short Cross-Pin Arrays and Comparison With Two Dimensional Calculations

1999 ◽  
Author(s):  
E. E. Donahoo ◽  
C. Camci ◽  
A. K. Kulkarni ◽  
A. D. Belegundu
Keyword(s):  
Heat Transfer ◽  
Turbine Blade ◽  
Structural Integrity ◽  
Turbine Blades ◽  
Circular Cross Section ◽  
Internal Cooling ◽  
Flow And Heat Transfer ◽  
High Heat Transfer ◽  
Spacing Ratio ◽  
Cooling Passage

There are many heat transfer augmentation methods that are employed in turbine blade design, such as impingement cooling, film cooling, serpentine passages, trip strips, vortex chambers, and pin fins. The use of crosspins in the trailing edge section of turbine blades is commonly a viable option due to their ability to promote turbulence as well as supply structural integrity and stiffness to the blade itself. Numerous crosspin shapes and arrangements are possible, but only certain configurations offer high heat transfer capability while maintaining taw total pressure loss. This study preseots results from 3-D numerical simulations of airflow through a turbine blade internal cooling passage. The simulations model viscous flow and heat transfer over full crosspins of circular cross-section with fixed height-to-diameter ratio of 0.5, fixed transverse-to-diameter spacing ratio of 1.5, and varying streamwise spacing. Preliminary analysis indicates that endwall effects dominate the flow and heat transfer at lower Reynolds numbers. The flow dynamics involved with the relative dose proximity of the endwalls for such short crosspins have a definite influeoce on crosspin efficiency for downstream rows.

Laminar flow and heat transfer in a periodic serpentine channel with semi-circular cross-section

2006 ◽  
Vol 49 (17-18) ◽  
pp. 2912-2923 ◽  
Author(s):  
Nathan R. Rosaguti ◽  
David F. Fletcher ◽  
Brian S. Haynes
Keyword(s):  
Heat Transfer ◽  
Laminar Flow ◽  
Cross Section ◽  
Circular Cross Section ◽  
Serpentine Channel ◽  
Flow And Heat Transfer

A Multiobjective Parameter Study of Two-Phase Flow Channel Design

2020 ◽  
Author(s):  
Nicholas A. Evich ◽  
Nicholas R. Larimer ◽  
Mary I. Frecker ◽  
Matthew J. Rau
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Two Phase Flow ◽  
Circular Cross Section ◽  
Parameter Study ◽  
Phase Flow ◽  
Two Phase ◽  
Flow And Heat Transfer ◽  
High Heat Transfer ◽  
Manufacturing Techniques

Abstract Advanced manufacturing techniques have improved dramatically in recent years and design freedom for engineered components and systems has never been greater. Despite these advancements, the majority of our design tools for thermal-fluids systems are still rooted within traditional architectures and manufacturing techniques. In particular, the complex nature of two-phase flow and heat transfer has made the development of design methods that can accommodate these complex geometries enabled by new manufacturing techniques challenging. Here, we investigate a new design method for two-phase flow systems. We conduct a multiobjective parameter study considering two-phase flow and heat transfer through a single channel with a circular cross section. To increase our design degrees of freedom, we allow the channel to increase or decrease in cross-sectional area along its flow length, but constrain the channel inlet and outlet to a constant hydraulic diameter. Maximizing heat transfer and minimizing pressure drop are the two design objectives, which we evaluate using two-phase heat transfer correlations and the Homogeneous Equilibrium Model. We find that using small expansion angles can greatly reduce two-phase flow pressure drop and also provide high heat transfer coefficients when compared to straight channel designs. We present a set of feasible designs for varying input heat fluxes, liquid mass flow rates, and channel orientation angles and show how the ideal expansion channel angle varies with these operational conditions.

scholarly journals Analyzing the Heat Transfer Property of Heat Pipe Influenced by Integrated Cooling Apparatus

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Chen-Ching Ting ◽  
Chien-Chih Chen
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Heat Pipe ◽  
Cooling Water ◽  
Cooling Power ◽  
Capillary Structure ◽  
Transfer Property ◽  
Face To Face ◽  
Heat Transfer Property ◽  
Circulating Cooling Water

Heat pipe with discrete heat transfer property is often called thermal superconductor because it has extremely large thermal conductivity. This special heat transfer property is destroyed by integrating cooling apparatus and further reducing the cooling power of a heat pipe cooler. This paper experimentally studied the heat transfer property of heat pipe influenced by integrated cooling apparatus. To simplify the investigating process, a home-made square heat pipe with the dimensions of L×W×H=10×10×100 mm3 was built with two pieces of copper plates and two pieces of glass plates face to face, respectively. The two pieces of copper plates were constructed with inside walls of capillary structure and the two pieces of glasses were with antifog inside walls for observing the inner phenomenon. Moreover, isothermal circulating cooling water was applied outside the heat pipe instead of cooling fin. The results show that heat vapor in the heat pipe is condensed earlier and cannot reach the remote section of condenser. In other words, the heat transfer property of heat pipe is destroyed by integrating cooling water. This phenomenon causes the unfavorable cooling power of the heat pipe cooler.

Simulation Study on Heat Insulating Material Used in Refrigerated Cargo Hold Shipboard of Fishing Vessel

2011 ◽  
Vol 311-313 ◽  
pp. 1953-1956
Author(s):  
Jing Fu Jia ◽  
Wei He
Keyword(s):  
Heat Transfer ◽  
Three Dimensional ◽  
Heat Transfer Process ◽  
Transfer Model ◽  
Fishing Vessel ◽  
Transfer Property ◽  
Insulating Material ◽  
Temperature Distributions ◽  
Heat Transfer Property ◽  
Computational Fluid Dynamics Cfd

To choose the suitable heat insulating material for refrigerated cargo hold shipboard of fishing vessel, a steady state three-dimensional mathematical model of heat transfer is developed in this paper. The heat-transfer model is simplified reasonably in order to facilitate analyzing and solving. After defining the boundary conditions of the model according to the heat-transfer process of the shipboard, numerical simulations with different heat insulating material are performed using computational fluid dynamics (CFD) software PHOENICS. The obtained temperature distributions of the model in each case are analyzed. The suitable one is pointed out according to the degree of influence of the heat insulating material on heat-transfer property of the shipboard.

Design and Heat Transfer Property of the Warming Compound Blocks Contained Slag Concrete

2013 ◽  
Vol 712-715 ◽  
pp. 869-872
Author(s):  
Jiang San Zheng ◽  
Gao Zhan Zhang ◽  
Shao Feng Zhu
Keyword(s):  
Heat Transfer ◽  
Thermal Resistance ◽  
Thermal Property ◽  
Transfer Property ◽  
Heat Transfer Property ◽  
New Type ◽  
Aerated Concrete

In this paper, a new type of warming compound blocks with slag concrete was designed and prepared. The effect of specification, hole pattern and form of warming compound blocks on the thermal property of the blocks was researched. The results show that, with the addition of slag, EPS and aerated concrete, the thermal property will be improved greatly. The thermal resistance of warming compound blocks with three rows of EPS would reach 1.13 m2•K/W, and the thermal resistance of warming compound blocks with three rows of aerated concrete would reach 0.83 m2•K/W.

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