Numerical Inverse Heat Transfer Analysis for Temperature-Sensitive-Paint Measurements in Hypersonic Tunnels

2011 ◽  
Vol 25 (1) ◽  
pp. 59-67 ◽  
Author(s):  
Zemin Cai ◽  
Tianshu Liu ◽  
Bo Wang ◽  
Justin Rubal ◽  
John P. Sullivan
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Analysis ◽  
Temperature Sensitive ◽  
Inverse Heat Transfer ◽  
Temperature Sensitive Paint

Temperature-Sensitive Paint Applications in the Heat Transfer Analysis of 90° Elbow Microchannel Flow with Sharp and Curved Turns

2020 ◽  
Vol 36 (4) ◽  
pp. 551-565
Author(s):  
Chih-Yung Huang ◽  
Jhih-Ren Lin ◽  
Tong-Miin Liou
Keyword(s):  
Heat Transfer ◽  
Surface Temperature ◽  
Constant Heat Flux ◽  
Heat Transfer Analysis ◽  
Temperature Sensitive ◽  
Microchannel Flow ◽  
Flux Boundary Condition ◽  
Micro Heat Exchanger ◽  
Axial Heat ◽  
Temperature Sensitive Paint

ABSTRACTThis study presents the heat transfer analysis of 90° elbow microchannel flow with sharp and curved turn designs. Experimental technique of temperature-sensitive paint was adapted in the experiment for measuring both fluid and surface temperature. The detailed information of fluid and surface temperature data were successfully acquired with a microscope system at Reynolds number varying from 50.5 to 101.1. Micro heaters were fabricated and positioned underneath the microchannel to provide the constant heat flux boundary condition. The utilization of micro heaters can prevent the axial heat conduction. The Nusselt number contours were obtained in this study with sharp and curved corners, which can provide detailed information of localized region with high and low heat transfer. The experimental approach performed in this study could be applied in the future for micro heat exchanger or heat sink design with complex microchannel systems.

Characterization of Tissue Thermal Conductivity During a Tissue Joining Process

2016 ◽  
Author(s):  
Che-Hao Yang ◽  
Yang Liu ◽  
Wei Li ◽  
Roland K. Chen
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Tissue Sample ◽  
Heat Transfer Analysis ◽  
Vessel Sealing ◽  
Inverse Heat Transfer ◽  
Thermal Spread ◽  
Higher Temperature ◽  
Postoperative Problems ◽  
Joining Process

Electrosurgical vessel sealing, a tissue joining process, has been widely used in surgical procedures, such as prostatectomies for bleeding control. The heat generated during the process may cause thermal damages to the surrounding tissues which can lead to detrimental postoperative problems. Having better understanding about the thermal spread helps to minimize these undesired thermal damages. The purpose of this study is to investigate the changes of tissue thermal conductivity during the joining process. We propose a hybrid method combining experimental measurement with inverse heat transfer analysis to determine thermal conductivity of thin tissue sample. Instead of self-heating the tissue by the thermistor, we apply an external cold boundary on the other side of the tissue sample to stimulate a higher temperature gradient without denaturing the tissue in comparison to the heated method. The inverse heat transfer technique was then applied to determine the tissue thermal conductivity. Tissue thermal conductivity at different levels (0%, 25%, 50%, 75%, and 100%) of the joining process was measured. The results show a decreasing trend in tissue thermal conductivity with increasing joining level. When the tissue is fully joined, an average of 60% reduction in tissue thermal conductivity was found.

Thermal Conductivity and Specific Heat Evaluation of Tissue Using Laser

2020 ◽  
Vol 1002 ◽  
pp. 303-310
Author(s):  
Sudad Issam Younis ◽  
Haqi I. Qatta ◽  
Mohammed Jalal Abdul Razzaq ◽  
Khalid S. Shibib
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Thermal Properties ◽  
Specific Heat ◽  
Iterative Procedure ◽  
Input Data ◽  
Maximum Error ◽  
Heat Transfer Analysis ◽  
Long Wavelength ◽  
Inverse Heat Transfer

In this work, an inverse heat transfer analysis was used to determine thermal conductivity and specific heat of tissue using special iteration. A laser with a long wavelength was utilized to impose heat to the tissue. The heat that induced in the sample causes an increase in the temperature of a tissue which is measured by a thermocouple. The readings were used together with that analytically obtained from the solution of the heat equation in an iterative procedure to obtain the thermal properties of tissue. By using this method, accurate thermal conductivity and specific heat of tissue could be obtained. It was found that the maximum error in output result and the error in input data were in the same order and that there was a linear relationship between output and input errors.

Inverse Heat Transfer Analysis of Micro Heater Strength and Locations for Hyperthermia Treatment of Brain Tumors

2007 ◽  
Author(s):  
Maral Biniazan ◽  
Kamran Mohseni
Keyword(s):  
Heat Transfer ◽  
Brain Tumors ◽  
Transfer Problem ◽  
The Body ◽  
Least Square ◽  
Bioheat Transfer ◽  
Heat Transfer Analysis ◽  
Whole Body ◽  
Transient Temperature ◽  
Inverse Heat Transfer

Hyperthermia, also called thermal therapy or thermotherapy, is a type of cancer treatment in which the aim is to maintain the surrounding healthy tissue at physiologically normal temperatures and expose the cancerous region to high temperatures between 43°C–45°C. Several methods of hyperthermia are currently under study, including local, regional, and whole-body hyperthermia. In local hyperthermia, Interstitial techniques are used to treat tumors deep within the body, such as brain tumors. heat is applied to the tumor, usually by probes or needles which are inserted into the tumor. The heat source is then inserted into the probe. Invasive interstitial heating technique offer a number of advantages over external heating approaches for localizing heat into small tumors at depth. e. g interstitial technique allows the tumor to be heated to higher temperatures than external techniques. This is why an innovative internal hyperthermia research is being conducted in the design of an implantable microheater [1]. To proceed with this research we need complete and accurate data of the strength, number and location of the micro heaters, which is the objective of this paper. The location, strength, and number of implantable micro heaters for a given tumor size is calculated by solving an Inverse Heat Transfer Problem (IHTP). First we model the direct problem by calculating the transient temperature field via Pennies bioheat transfer equation. A nonlinear least-square method, modified by addition of a regularization term, Levenberg Marquardt method is used to determine the inverse problem [2].

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