Numerical Simulation for Flow and Heat Transfer Characteristics of LType Chaotic Channel

2015 ◽  
Vol 8 (1) ◽  
pp. 351-355
Author(s):  
Kan Cao ◽  
Minshan Liu ◽  
Yongqing Wang ◽  
Zunchao Liu
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Temperature Field ◽  
Flow Field ◽  
Cross Sections ◽  
Straight Channel ◽  
Flow And Heat Transfer ◽  
Periodic Model ◽  
Chaotic Convection ◽  
Better Than

In this paper, the author conducted numerical simulation on fluid flow and heat transfer of L-type chaotic channel with the use of periodic model, compared with common straight channel, analyzed and gained microscopic information flow field and temperature field distribution inside the channel, researched synergy of flow field and temperature field inside the channel with the use of synergy principle, and discussed influences of different Re figures on fluid heat transfer and flow inside the chaotic channel. Results show that L-type chaotic structure can generate chaotic convection under lower flow velocity, which increases disturbing degree of fluid inside the channel, so as to promote mixture and heat transfer of cold and hot fluid; synergy degree of velocity and temperature gradient on cross section of chaotic channel are better than that of straight channel, and average synergy angles for outlet cross sections of such two channels are respectively 66.3° and 88.0°; Nu number of L-type chaotic channel increases with the increase of Re. Particularly, increasing range is more obvious at low Reynolds number, but at the same time, friction coefficient inside the channel will increase.

Numerical Simulation on Process of Flow and Heat Transfer in Upright Magnesium Reducing Furnace

2011 ◽  
Vol 383-390 ◽  
pp. 6657-6662 ◽  
Author(s):  
Jun Xiao Feng ◽  
Qi Bo Cheng ◽  
Si Jing Yu
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Temperature Field ◽  
Flue Gas ◽  
Gas Flow ◽  
Three Dimensional ◽  
Reaction Heat ◽  
Flow And Heat Transfer ◽  
Major Factors ◽  
High Chemical Reaction

Based on the analysis of structural characteristic superiority, the process of combustion, flue gas flow and heat transfer in the upright magnesium reducing furnace, the three dimensional mathematical model is devoloped. And numerical simulation is performed further with the commercial software FLUENT. Finally, the flow and temperature field in furnace and temperature field in reducing pot have been obtained. The results indicate that the upright magnesium reducing furnace has perfect flue gas flow field and temperature field to meet the challenge of the magnesium reducing process; the major factors that affect the magnesium reducing reaction are the low thermal conductivity of slag and the high chemical reaction heat absorption.

Natural Convection of Nanofluid in a Triangle Cavity with Different Angular Positions

2020 ◽  
Vol 12 (3) ◽  
pp. 325-329
Author(s):  
Mohsen Rostami ◽  
Mohammad Saleh Abadi
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Natural Convection ◽  
Flow Field ◽  
Boundary Conditions ◽  
Angular Position ◽  
Numerical Results ◽  
Heat Transfer Characteristics ◽  
Current Structure ◽  
Flow And Heat Transfer

The effects of the angular position on the flow and heat transfer of the nanofluid in a triangular cavity is investigated numerically. A triangular cavity is chosen with the same boundary conditions as the published results are available. The comparison between the current numerical results with the available data is made to show the accuracy of the numerical simulation. The current structure of triangular cavity is rotated to investigate the effects of various angular positions on the flow and heat transfer characteristics of nanofluid. For this purpose, the equations of continuity, momentum and energy are solved numerically. The results show that the hot fluid is more freely penetrated into the domain by increasing of the angular position. The velocity of fluid in the flow field becomes maximum for the angle of 120 . Also, the creation of vortices in the flow field depends on the value of angular position.

Study on the Numerical Simulation of Surface Flow and Heat Transfer in Inclined Wave Fin-and-Tube Heat Exchanger

2013 ◽  
Vol 353-356 ◽  
pp. 3081-3084
Author(s):  
Jun Zhai ◽  
Meng Qin ◽  
Feng Guo Liu
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Heat Exchanger ◽  
Finned Tube ◽  
Surface Flow ◽  
Inlet Velocity ◽  
Tube Heat Exchanger ◽  
Flow And Heat Transfer ◽  
Pressure Resistance ◽  
Better Than

With the CFD calculation software FLUENT, numerical simulation has been conducted to study the surface flow and heat transfer in inclined wave fin-and-tube heat exchanger, including uniform angle wave fin and inclined increase-angle wave fin. Velocity field, pressure field and the distribution of temperature field on the air side of fin surface were obtained. Heat transfer performance of the two kinds of fin were discussed and the curve of both heat exchange and pressure drop related to the inlet velocity were analyzed. The results indicates that in the same conditions, heat transfer effect is better than uniform angle wave fin. When the inlet velocity is 4 m/s ,the heat transfer of inclined increase-angle wave fin is about 1.1 times higher than that of uniform angle wave fin meanwhile the pressure resistance is as much as around 1.2 times, which provides a theoretical basis on heat transfer enhancement of wave finned tube.

Effect of External Magnetic Field on the Flow and Heat Transfer in DC Arc Plasma Torch

2010 ◽  
Vol 97-101 ◽  
pp. 2797-2800
Author(s):  
Da Pei Tang ◽  
Qing Gao ◽  
Ying Hui Li ◽  
Fan Xiu Lu
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Temperature Field ◽  
External Magnetic Field ◽  
Flow Field ◽  
Electric Field ◽  
Diamond Film ◽  
Plasma Torch ◽  
Current Intensity ◽  
Flow And Heat Transfer

A multiple fields’ coupled model of new magnetic controlled DC plasma torch, which was used for CVD diamond film, was presented. In this model, the effects of electric field and magnetic field on the flow field and temperature field were taken into account, and the fluid dynamics equations were modified by the addition of some source terms relating to electromagnetic field, such as Lorentz force, joule heating, and radiative cooling. Conversely, the generalized ohm’s law was used to solve the current density, which reflected the effects of flow field and temperature field on the electric field and magnetic field. In addition, the rest Maxwell’s equations and external solenoid magnetic field equation were also modeled. In order to know the effect of external magnetic field on the torch, the current intensity of external solenoid was chosen to simulate its influence on the flow and heat transfer in the torch. Results show that external magnetic field plays a part in stirring the plasma, which is advantageous for the preparation of diamond film. The larger the external solenoid current intensity is, the better the uniformity of the temperature and velocity of plasma is.

scholarly journals Microscale flow and heat transfer between the rotor and the flank for rotary engine

2019 ◽  
pp. 330-330
Author(s):  
Zhaoju Qin
Keyword(s):  
Heat Transfer ◽  
Temperature Field ◽  
Flow Field ◽  
Velocity Slip ◽  
Coupling Model ◽  
Rotary Engine ◽  
Flow And Heat Transfer ◽  
Microscale Flow ◽  
Commercial Code ◽  
Steady Laminar

This paper is to investigate microscale flow and transfer between the rotor and the flank for rotary engine. The rotor and flank is simplified to two disks in order to study flow field and temperature field conveniently. The paper takes analysis of steady laminar flow and heat transfer between two disks separated by a gas-filled gap due to machining tolerance. A 3-D multi-physical coupling model is used, involving velocity slip, temperature jump, rarefaction and dissipation. A solution based on commercial code COMSOL is derived and the results are used to illustrate the effects to velocity field, temperature distribution, disks' torque and Nusselt number based on the governing parameters. The paper also investigates the effects of different modified Knudsen number on flow field and temperature field.

Fully Developed Flow and Heat Transfer in Ducts Having Streamwise-Periodic Variations of Cross-Sectional Area

1977 ◽  
Vol 99 (2) ◽  
pp. 180-186 ◽  
Author(s):  
S. V. Patankar ◽  
C. H. Liu ◽  
E. M. Sparrow
Keyword(s):  
Heat Transfer ◽  
Temperature Field ◽  
Flow Field ◽  
Cross Sectional Area ◽  
Bulk Temperature ◽  
Sectional Area ◽  
Cross Sectional ◽  
Reduced Pressure ◽  
Fully Developed Flow ◽  
Flow And Heat Transfer

The concepts of fully developed flow and heat transfer have been generalized to accommodate ducts whose cross-sectional area varies periodically in the streamwise direction. The identification of the periodicity characteristics of the velocity components and of a reduced pressure function enables the flow field analysis to be confined to a single isolated module, without involvement with the entrance region problem. A similar modular analysis can be made for the temperature field, but the periodicity conditions are of a different nature depending on the thermal boundary conditions. For uniform wall temperature, profiles of similar shape recur periodically. On the other band, for prescribed wall heat flux which is the same for all modules, the temperature field itself is periodic provided that a linear term related to the bulk temperature change is subtracted. The concepts and solution procedure for the periodic fully developed regime were applied to a heat exchanger configuration consisting of successive ranks of isothermal plate segments placed transverse to the mainflow direction. The computed laminar flow field was found to be characterized by strong blockage effects and massive recirculation zones. The fully developed Nusselt numbers are much higher than those for conventional laminar duct flows and show a marked dependence on the Reynolds number.

Fundamental Issues and Recent Advancements in Analysis of Aircraft Brake Natural Convective Cooling

1998 ◽  
Vol 120 (4) ◽  
pp. 840-857 ◽  
Author(s):  
M. P. Dyko ◽  
K. Vafai
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Flow Field ◽  
Three Dimensional ◽  
Convective Cooling ◽  
Cooling Flow ◽  
Physical Mechanisms ◽  
Braking System ◽  
Flow And Heat Transfer ◽  
Convection Cooling

A heightened awareness of the importance of natural convective cooling as a driving factor in design and thermal management of aircraft braking systems has emerged in recent years. As a result, increased attention is being devoted to understanding the buoyancy-driven flow and heat transfer occurring within the complex air passageways formed by the wheel and brake components, including the interaction of the internal and external flow fields. Through application of contemporary computational methods in conjunction with thorough experimentation, robust numerical simulations of these three-dimensional processes have been developed and validated. This has provided insight into the fundamental physical mechanisms underlying the flow and yielded the tools necessary for efficient optimization of the cooling process to improve overall thermal performance. In the present work, a brief overview of aircraft brake thermal considerations and formulation of the convection cooling problem are provided. This is followed by a review of studies of natural convection within closed and open-ended annuli and the closely related investigation of inboard and outboard subdomains of the braking system. Relevant studies of natural convection in open rectangular cavities are also discussed. Both experimental and numerical results obtained to date are addressed, with emphasis given to the characteristics of the flow field and the effects of changes in geometric parameters on flow and heat transfer. Findings of a concurrent numerical and experimental investigation of natural convection within the wheel and brake assembly are presented. These results provide, for the first time, a description of the three-dimensional aircraft braking system cooling flow field.

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