Skin Temperature Probe

1979 ◽  
Vol 101 (4) ◽  
pp. 232-238 ◽  
Author(s):  
S. D. Mahanty ◽  
R. B. Roemer
Keyword(s):  
Numerical Model ◽  
Skin Temperature ◽  
Skin Surface ◽  
Experimental Calibration ◽  
Temperature Probe ◽  
Surface Temperatures ◽  
Model Predictions

A probe which is capable of applying known, controlled pressures to the skin, and measuring the subsequent tissue deflections and skin surface temperatures has been designed and tested. This paper describes the design of the probe, with emphasis on the thermal aspects. The fin effect of the probe superstructure is compensated for by providing an appropriately sized reflective area on that portion of the probe which contacts the skin. Experimental calibration results and numerical model predictions are presented.

Comparison of Four Friction Models: Feature Prediction

2015 ◽  
Vol 11 (3) ◽  
Author(s):  
Yun-Hsiang Sun ◽  
Tao Chen ◽  
Christine Qiong Wu ◽  
Cyrus Shafai
Keyword(s):  
Numerical Model ◽  
Viscous Friction ◽  
Friction Model ◽  
Dynamic Features ◽  
Numerical Predictions ◽  
Wide Range ◽  
Model Predictions ◽  
Friction Models ◽  
Parameter Identifications ◽  
Model Structures

In this paper, we provide not only key knowledge for friction model selection among candidate models but also experimental friction features compared with numerical predictions reproduced by the candidate models. A motor-driven one-dimensional sliding block has been designed and fabricated in our lab to carry out a wide range of control tasks for the friction feature demonstrations and the parameter identifications of the candidate models. Besides the well-known static features such as break-away force and viscous friction, our setup experimentally demonstrates subtle dynamic features that characterize the physical behavior. The candidate models coupled with correct parameters experimentally obtained from our setup are taken to simulate the features of interest. The first part of this work briefly introduces the candidate friction models, the friction features of interest, and our experimental approach. The second part of this work is dedicated to the comparisons between the experimental features and the numerical model predictions. The discrepancies between the experimental features and the numerical model predictions help researchers to judge the accuracy of the models. The relation between the candidate model structures and their numerical friction feature predictions is investigated and discussed. A table that summarizes how to select the most optimal friction model among a variety of engineering applications is presented at the end of this paper. Such comprehensive comparisons have not been reported in previous literature.

scholarly journals Effects of skin heat conduction on aircraft icing process

2020 ◽  
pp. 095441002097257
Author(s):  
Xiaobin Shen ◽  
Yu Zeng ◽  
Guiping Lin ◽  
Zuodong Mu ◽  
Dongsheng Wen
Keyword(s):  
Heat Conduction ◽  
Temperature Distribution ◽  
Skin Temperature ◽  
Accretion Rate ◽  
Skin Surface ◽  
Ice Thickness ◽  
Ice Accretion ◽  
Aircraft Icing ◽  
Outer Skin ◽  
Lateral Heat

During the aircraft icing process caused by super-cooled droplet impingement, the surface temperature and heat flux distributions of the skin would vary due to the solid substrate heat conduction. An unsteady thermodynamic model of the phase transition was established with a time-implicit solution algorithm, in which the solid heat conduction and the water freezing were analyzed simultaneously. The icing process on a rectangular skin segment was numerically simulated, and the variations of skin temperature distribution, thicknesses of ice layer and water film were obtained. Results show that the presented model could predict the icing process more accurately, and is not sensitive to the selection of time step. The latent heat released by water freezing affects the skin temperature, which in turn changes the icing characteristics. The skin temperature distribution would be affected notably by the boundary condition of the inner skin surface, the lateral heat conduction and thermal property of the skin. It was found that the ice accretion rate of the case that the inner surface boundary is in natural convection at ambient temperature is much smaller than that with constant ambient temperature there; due to the skin lateral heat conduction, the outer skin surface temperature increases first and then decreases with uneven distribution, leading to an unsteady ice accretion rate and uneven ice thickness distribution; a smaller heat conductivity would lead to a more uneven temperature distribution and a lower ice accretion rate in most regions, but the maximum ice thickness could be larger than that of higher heat conductivity skin. Therefore, in order to predict the aircraft icing phenomenon more accurately, it is necessary to consider the solid heat conduction and the boundary conditions of the skin substrate, instead of applying a simple boundary condition of adiabatic or a fixed temperature for the outer skin surface.

scholarly journals Mode-I Fracture Behavior of CFRPs: Numerical Model of the Experimental Results

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 513 ◽  
Author(s):  
Claudia Barile ◽  
Caterina Casavola ◽  
Benedetto Gambino ◽  
Alessandro Mellone ◽  
Marco Spagnolo
Keyword(s):  
Numerical Model ◽  
Composite Laminates ◽  
High Performance ◽  
Mechanical Response ◽  
Numerical Models ◽  
Constitutive Relationship ◽  
Mode I ◽  
Experimental Calibration ◽  
Reinforced Plastics ◽  
High Performance Composite

In the last decades, the increasing use of laminate materials, such as carbon fibre reinforced plastics, in several engineering applications has pushed researchers to deeply investigate their mechanical behavior, especially in consideration of the delamination process, which could affect their performance. The need for improving the capability of the current instruments in predicting some collapse or strength reduction due to hidden damages leads to the necessity to combine numerical models with experimental campaigns. The validation of the numerical models could give useful information about the mechanical response of the materials, providing predictive data about their lifetime. The purpose of the delamination tests is to collect reliable results by monitoring the delamination growth of the simulated in situ cracking and use them to validate the numerical models. In this work, an experimental campaign was carried out on high performance composite laminates with respect to the delamination mode I; subsequently, a numerical model representative of the experimental setup was built. The ANSYS Workbench Suite was used to simulate the delamination phenomena and modeFRONTIER was applied for the numerical/experimental calibration of the constitutive relationship on the basis of the delamination process, whose mechanism was implemented by means of the cohesive zone material (CZM) model.

Ideal Site for Skin Temperature Probe Placement on Infants in the NICU

2017 ◽  
Vol 17 (2) ◽  
pp. 114-122 ◽  
Author(s):  
Rachel A. Joseph ◽  
Sarah Derstine ◽  
Michaela Killian
Keyword(s):  
Skin Temperature ◽  
Temperature Probe ◽  
Probe Placement

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.

The Kettles Hill Project: Field observations, wind-tunnel simulations and numerical model predictions for flow over a low hill

1988 ◽  
Vol 43 (4) ◽  
pp. 309-343 ◽  
Author(s):  
J. R. Salmon ◽  
H. W. Teunissen ◽  
R. E. Mickle ◽  
P. A. Taylor
Keyword(s):  
Numerical Model ◽  
Wind Tunnel ◽  
Field Observations ◽  
Model Predictions

Effect of skin temperature on multifrequency bioelectrical impedance analysis

1996 ◽  
Vol 81 (2) ◽  
pp. 838-845 ◽  
Author(s):  
R. Gudivaka ◽  
D. Schoeller ◽  
R. F. Kushner
Keyword(s):  
Skin Temperature ◽  
Bioelectrical Impedance ◽  
Impedance Analysis ◽  
Skin Surface ◽  
Body Water ◽  
Heating And Cooling ◽  
Water Compartments ◽  
Multifrequency Bioimpedance ◽  
Measured Impedance ◽  
Total Body

This study assessed the effects of changes in skin temperature on multifrequency bioimpedance analysis (MF-BIA) and on the prediction of body water compartments. Skin temperature (baseline 29.3 +/- 2.1 degrees C) of six healthy adults was raised over 50 min to 35.8 +/- 0.6 degrees C, followed by cooling for 20 min to 26.9 +/- 1.3 degrees C, by using an external heating and cooling blanket. MF-BIA was measured at both distal (conventional) and proximal electrode placements. Both distal and proximal impedance varied inversely with a change in skin temperature across all frequencies (5–500 kHz). The change in proximal impedance per degree centigrade change in skin surface temperature was approximately 60% of distal impedance. The change in measured impedance at 50 kHz erroneously increased predicted total body water (TBW) by 2.6 +/- 0.9 liters (P < 0.001) and underpredicted fat mass by 3.3 +/- 1.3 kg (P < 0.0001). Computer modeling of the MF-BIA data indicated changes in predicted water compartments with temperature modifications; however, the ratio of extracellular water (ECW) to TBW did not significantly change (P < 0.4). This change in impedance was not due to a change in the movement of water of the ECW compartment and thus probably represents a change in cutaneous impedance of the skin. Controlled ambient and skin temperatures should be included in the standardization of BIA measurements. The error in predicted TBW is < 1% within an ambient temperature range of 22.3 to 27.7 degrees C (72.1–81.9 degrees F).

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