Simulation and Analysis of Three-Dimensional Arterial Trees

2013 ◽  
Vol 475-476 ◽  
pp. 1603-1606
Author(s):  
Yan Zhang ◽  
Hai Wei Xie
Keyword(s):  
Heat Transfer ◽  
Bifurcation Point ◽  
Three Dimensional ◽  
Mass Conservation ◽  
Heat Transfer Analysis ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Arterial Tree ◽  
Hemodynamic Simulation ◽  
Bifurcation Law

For hemodynamic simulation and heat transfer analysis of blood, it is necessary to generate a three-dimensional model of arterial tree. Referring to the approach of Constrained Constructive Optimization (CCO), a new method based on bifurcation law, Poiseuilles law and mass conservation was proposed to model arterial trees directly in simulation objects. The formulas for calculating the bifurcation ratios and the way to determine the location of bifurcation point were presented in the paper. In this model, the radius of the root segment was constant, the terminal pressure was unknown and the bifurcation exponent was variable. In order to demonstrate the feasibility of this method, an arterial tree was constructed in a spherical tissue.

Flow and Heat Transfer Computations in a Rotating Cavity With Tangential Seal Air Flow

1997 ◽  
Author(s):  
Prabhat Tekriwal
Keyword(s):  
Heat Transfer ◽  
Air Flow ◽  
Three Dimensional ◽  
Thermomechanical Analysis ◽  
Heat Transfer Analysis ◽  
Symmetric Model ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Life Study ◽  
Analysis And Design

Axi-symmetric and three-dimensional CFD models for a rotating open interdisk cavity have been developed to predict flow, heat transfer, windage power loss and cavity air temperatures as a part of the rotor thermomechanical analysis and design life study. The cavity has a tangential (axial and circumferential) seal air flow above it. The rotational Reynolds number is 4.8 × 106 and the non-dimensional seal flow rate is 9.8 × 104. Measured wall temperatures are used as boundary conditions in the model. The axi-symmetric model smears the cavity bolts as 360° continuous rings and therefore ignores the bolts pumping effect. The windage loss calculation from the axi-symmetric model is in good agreement with the experimental data in the literature. The heat transfer coefficient values from the axi-symmetric and three-dimensional models are comparable in most of the regions apart from near the bolts. Also, the three-dimensional model simulates the bolt pumping effects and yields a much higher windage loss value, which in turn raises the cavity air temperature. It is concluded that a three-dimensional model is necessary for an accurate heat transfer analysis.

scholarly journals UNSTEADY HEAT TRANSFER IN A HORIZONTAL GROUND HEAT EXCHANGER

2018 ◽  
Vol 40 (4) ◽  
pp. 34-40
Author(s):  
B.I. Basok ◽  
B.V. Davidenko ◽  
I.K. Bozhko ◽  
M.V. Moroz
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Three Dimensional ◽  
Heat Transfer Agent ◽  
Ground Heat Exchanger ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Unsteady Heat Transfer ◽  
Pump System ◽  
Heat Pump System

By the three-dimensional model of heat transfer in the system "ground - horizontal ground heat exchanger - heat transfer agent", an analysis of the efficiency of the horizontal multi-loop heat exchanger, which is an element of the heat pump system, was carried out. Based on the results of numerical simulation, the time dependence of the heat transfer agent temperature at the outlet from the ground heat exchanger and the amount of heat extracted from the ground is determined. The results of calculations by the presented model are satisfactorily agree with the experimental data.

Performance Evaluation of Thermal Attributes in Impinging Jet Heat Sink using Airfoil Pillars with and without Nano Fluid

2021 ◽  
Vol 7 (5) ◽  
pp. 2808-2820
Author(s):  
Deepak Kumar ◽  
Mohammad Zunaid ◽  
Samsher Gautam
Keyword(s):  
Heat Transfer ◽  
Heat Sink ◽  
Three Dimensional ◽  
Thermal Characteristics ◽  
Exchange Coefficient ◽  
Dimensional Model ◽  
Heat Exchange Coefficient ◽  
Three Dimensional Model ◽  
Nano Fluid ◽  
Nano Fluids

Objectives: In the current research three techniques have been operated to enhance the rate of heat transfer in a heat sink. The amalgamation of Impingement of jet, airfoil pillars and Nano fluids are used. Nano fluids has a lot of potential to enhance the heat transportation in contrast to the water. The investigation has been executed with the help of three dimensional numerical model using Computational fluid Dynamics. At the onset the model has been validated with the inspection carried out already in experimental form. The observations in the form of thermal attributes are investigated. From the results the conclusion is made that the use of airfoil pillars and Nano fluids has increased the thermal characteristics of the three dimensional model in the form of heat exchange coefficient by almost 28.2%. The Nano fluid has been utilized for the 0.5% concentration.

The Effects of Side-Wall Conduction on Natural Convection in a Slot

1987 ◽  
Vol 109 (2) ◽  
pp. 419-426 ◽  
Author(s):  
G. D. Mallinson
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Radiation Effects ◽  
Three Dimensional ◽  
Side Wall ◽  
Thermal Coupling ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
High Prandtl Number ◽  
Side Walls

A numerical model for the interaction between natural convection in a slot and conduction in the side walls that are parallel to the plane of the slot is described. Two-dimensional equations containing source terms which account for the viscous and thermal coupling between the fluid and the walls are solved by a finite difference method. The model neglects radiation effects. Solutions for a slot of square cross section filled with a high Prandtl number fluid and heated from below are compared with the results of a Galerkin analysis made by Frick [8] and with solutions obtained by a fully three-dimensional model. Solutions for a slot filled with air and heated from the side are also validated by comparison with three-dimensional solutions. The data produced by the model predict that the more conventional Hele Shaw analysis overestimates heat transfer when the slot aspect ratio is greater than 0.05. Perfectly conducting walls are shown to reduce the rate of heat transfer by the fluid but to increase the strength of the flow. Some effects of walls that are neither adiabatic nor perfectly conducting are assessed.

Liquid Flow Characteristics in Microchannels

2011 ◽  
Vol 130-134 ◽  
pp. 1484-1490
Author(s):  
Yan Feng Liu ◽  
Hong Wei Li ◽  
Jing Wei Zhang ◽  
Jin Xue
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Fluid Flow ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Simulation Methods ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Simulation Results ◽  
Poiseuille Number

A three-dimensional model was developed to simulate the laminar flow and convective heat transfer in rectangular silicon microchannels，which have hydraulic diameter of 95.3，92.3 ,85.8 , 80 and 75μm respectively．The rationality of the simulation methods and results were validated by comparing with experimental data. The simulation results indicate that the aspect ratio has a significant impact on the Poiseuille number. Conventional fluid flow theory is fit for researching the fluid flow in microchannels, Po is a constant that is not dependent on the Reynolds number.

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