Effect of Forced Convection on the Skin Thermal Expression of Breast Cancer

2004 ◽  
Vol 126 (2) ◽  
pp. 204-211 ◽  
Author(s):  
Lu Hu ◽  
Ashish Gupta ◽  
Jay P. Gore ◽  
Lisa X. Xu
Keyword(s):  
Forced Convection ◽  
Conjugate Heat Transfer ◽  
Transfer Problem ◽  
Skin Surface ◽  
Bioheat Transfer ◽  
Image Subtraction ◽  
Steady State Temperature ◽  
Parametric Studies ◽  
Airflow Field ◽  
Thermal Signature

A bioheat-transfer-based numerical model was utilized to study the energy balance in healthy and malignant breasts subjected to forced convection in a wind tunnel. Steady-state temperature distributions on the skin surface of the breasts were obtained by numerically solving the conjugate heat transfer problem. Parametric studies on the influences of the airflow on the skin thermal expression of tumors were performed. It was found that the presence of tumor may not be clearly shown due to the irregularities of the skin temperature distribution induced by the airflow field. Nevertheless, image subtraction techniques could be employed to eliminate the effects of the flow field and thermal noise and significantly improve the thermal signature of the tumor on the skin surface. Inclusion of the possible skin vascular response to cold stress caused by the airflow further enhances the signal, especially for deeply embedded tumors that otherwise may not be detectable.

Numerical Simulation of Enhanced Skin Thermal Signature of Female Breast Tumor Subjected to Forced Convection

2003 ◽  
Author(s):  
A. Gupta ◽  
L. Hu ◽  
J. P. Gore ◽  
L. X. Xu
Keyword(s):  
Heat Transfer ◽  
Flow Field ◽  
Skin Temperature ◽  
Forced Convection ◽  
Infrared Imaging ◽  
Transfer Problem ◽  
Blood Perfusion ◽  
Skin Surface ◽  
Temperature Distributions ◽  
Thermal Signature

Early detection is considered to be the best defense against breast cancer and imaging plays a very important role in screening and in the diagnosis of symptomatic women. Infrared thermal imaging of skin temperature changes caused by a malignant tumor in breast is a rapidly developing detection modality with potential for functional detection. Knowledge and control of environmental factors which affect the skin temperature can reduce misinterpretations and false diagnosis associated with infrared imaging. A bio heat transfer based numerical model was utilized to study the energy balance in healthy and malignant breasts subjected to low velocity forced convection in a wind tunnel. Existing estimates of metabolic heating rates and previous measurements of temperature distributions along the radial direction in a region intersecting a known tumor and a comparable region in the healthy breast of the same patient were used to estimate the blood perfusion rates for the tumor. A simplified structural and thermal model was used for representing the changes within and around the tumor. Steady state temperature distributions on the skin surface of the breasts were obtained by numerically solving the conjugate heat transfer problem. Parametric studies on the influences of the airflow on the skin thermal expression of tumors were performed. It was found that the presence of tumor may not be clearly shown due to the irregularity of the skin temperature distribution induced by the flow field. Image processing techniques could be employed to eliminate the effects of the flow field and thermal noise and significantly improve the thermal signature of the tumor on the skin surface.

scholarly journals A finite element analysis on combined convection and conduction in a channel with a thick walled cavity

2014 ◽  
Vol 24 (8) ◽  
pp. 1888-1905 ◽  
Author(s):  
M.M. Rahman ◽  
Hakan Oztop ◽  
S. Mekhilef ◽  
R. Saidur ◽  
A. Chamkha ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Finite Element ◽  
Mixed Convection ◽  
Conjugate Heat Transfer ◽  
Transfer Problem ◽  
Thick Wall ◽  
Thermal Conductivity Ratio ◽  
Element Analysis ◽  
Content Type ◽  
Combined Convection

Purpose – The purpose of this paper is to examine the effects of thick wall parameters of a cavity on combined convection in a channel. In other words, conjugate heat transfer is solved. Design/methodology/approach – Galerkin weighted residual finite element method is used to solve the governing equations of mixed convection. Findings – The streamlines, isotherms, local and average Nusselt numbers are obtained and presented for different parameters. It is found heat transfer is an increasing function of dimensionless thermal conductivity ratio. Originality/value – The literature does not have mixed convection and conjugate heat transfer problem in a channel with thick walled cavity.

A Two-Dimensional Conjugate Heat Transfer Model for Forced Air Cooling of an Electronic Device

1989 ◽  
Vol 111 (1) ◽  
pp. 41-45 ◽  
Author(s):  
A. Zebib ◽  
Y. K. Wo
Keyword(s):  
Heat Transfer ◽  
Conjugate Heat Transfer ◽  
Electronic Device ◽  
Transfer Problem ◽  
Maximum Temperature ◽  
Transfer Model ◽  
Air Cooling ◽  
Two Dimensional ◽  
Component Design ◽  
Forced Air

Thermal analysis of forced air cooling of an electronic component is modeled as a two-dimensional conjugate heat transfer problem. The velocity field in a constricted channel is first computed. Then, for a typical electronic module, the energy equation is solved with allowance for discontinuities in the thermal conductivity. Variation of the maximum temperature with the average air velocity is presented. The importance of our approach in evaluating possible benefits due to changes in component design and the limitations of the two-dimensional model are discussed.

scholarly journals Two conjugate convection boundary-layers of counter forced flow

2018 ◽  
Vol 22 (2) ◽  
pp. 835-846
Author(s):  
Mohamed Mosaad
Keyword(s):  
Heat Transfer ◽  
Boundary Layers ◽  
Conjugate Heat Transfer ◽  
Transfer Problem ◽  
Forced Flow ◽  
Relative Importance ◽  
Counter Flow ◽  
Wide Range ◽  
Convection Boundary ◽  
Laminar Forced Convection

In this study, the conjugate heat transfer problem of two laminar forced convection boundary-layers of counter flow on the opposite sides of a conductive wall is analyzed by employing the integral method. The analysis is conducted in a dimensionless framework to generalize the solution. The dimensionless parameters affecting the thermal interaction between the two convection layers are deduced from the analysis. These parameters give a measure of the relative importance of interactive heat transfer modes. Mean Nusselt number data are obtained for a wide range of the main affecting parameters.

Solution of the Inverse Bioheat Transfer Problem for the Detection of Tumors by Genetic Algorithms

2017 ◽  
pp. 441-452
Author(s):  
Antonio Marcio Gonçalo Filho ◽  
Lucas Lagoa Nogueira ◽  
Joao Victor Caetano Silveira ◽  
Michelli Marlane Silva Loureiro ◽  
Felipe dos Santos Loureiro
Keyword(s):  
Genetic Algorithms ◽  
Transfer Problem ◽  
Bioheat Transfer

Uncoupling the Conjugate Heat Transfer Problem in a Horizontal Plate Under the Influence of a Laminar Flow

2003 ◽  
Author(s):  
Ricardo S. Va´squez ◽  
Antonio J. Bula
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Conjugate Heat Transfer ◽  
Energy Equation ◽  
Transfer Problem ◽  
Heat Transfer Problem ◽  
Interface Temperature ◽  
Horizontal Plate ◽  
Steady State Condition ◽  
Heated Body

The conjugate heat transfer process of cooling a horizontal plate in steady state condition is studied. The model considers both solid and fluid regions in Cartesian coordinates. The problem was solved analytically, considering the fluid flowing in a laminar condition and hydrodynamically developed before any interaction with the heated body. The height of the fluid considered was enough to allow the generation of a thermal boundary layer without any restriction. The conservation of mass, momentum and energy equations were considered to turn the problem into a non dimensional form. The heated body presented a constant heat flux at the bottom side, and convective heat transfer at the top side in contact with the fluid. The other two boundary conditions are adiabatic. The energy equation was considered in the solid to turn it into a non dimensional form. The interface temperature was obtained from a regression using the Chebyshev polynomial approximation. As the problem deals with the cooling of a electronics components, the solution presents the mathematical solution of the energy equation for the solid, including the isothermal lines. The non dimensional form allows a thorough analysis of the problem, considering the influence of the different parameters in the conjugate heat transfer problem. The solution is compared with numerical solution of different problems, and the parameters considered are Reynolds number, plate thickness, Prandtl number, and solid thermal conductivity. The results obtained present isothermal lines, local Nusselt number, and average Nusselt number.

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