Transient Temperature Involving Oscillatory Heat Source With Application in Fretting Contact

2007 ◽  
Vol 129 (3) ◽  
pp. 517-527 ◽  
Author(s):  
Jun Wen ◽  
M. M. Khonsari
Keyword(s):  
Heat Source ◽  
Oscillation Amplitude ◽  
The Body ◽  
Transient Temperature ◽  
Dimensionless Frequency ◽  
Heat Sources ◽  
Infinite Body ◽  
Fitting Method ◽  
Wide Range ◽  
Analytical Expressions

An analytical approach for treating problems involving oscillatory heat source is presented. The transient temperature profile involving circular, rectangular, and parabolic heat sources undergoing oscillatory motion on a semi-infinite body is determined by integrating the instantaneous solution for a point heat source throughout the area where the heat source acts with an assumption that the body takes all the heat. An efficient algorithm for solving the governing equations is developed. The results of a series simulations are presented, covering a wide range of operating parameters including a new dimensionless frequency ω¯=ωl2∕4α and the dimensionless oscillation amplitude A¯=A∕l, whose product can be interpreted as the Peclet number involving oscillatory heat source, Pe=ω¯A¯. Application of the present method to fretting contact is presented. The predicted temperature is in good agreement with published literature. Furthermore, analytical expressions for predicting the maximum surface temperature for different heat sources are provided by a surface-fitting method based on an extensive number of simulations.

Green’s Functions in Generalized Micropolar Thermoelasticity

1993 ◽  
Vol 46 (11S) ◽  
pp. S316-S326
Author(s):  
Ranjit S. Dhaliwal ◽  
Jun Wang
Keyword(s):  
General Solution ◽  
Heat Source ◽  
Body Force ◽  
The Body ◽  
Arbitrary Distribution ◽  
Heat Sources ◽  
Infinite Body ◽  
Body Forces ◽  
Micropolar Thermoelasticity ◽  
Short Time

General solution of the generalized micropolar thermoelastic equations has been obtained for arbitrary distribution of the body couples, body forces, and heat sources in an infinite body. Short time solutions have been obtained for the cases of impulsive body force and heat source acting at a point. Numerical values of the short time solutions have been displayed graphically.

Semi-infinite vortex trails, and their relation to oscillating airfoils

1972 ◽  
Vol 54 (4) ◽  
pp. 679-690 ◽  
Author(s):  
D. Weihs
Keyword(s):  
Iterative Procedure ◽  
Constant Width ◽  
Oscillation Amplitude ◽  
The Body ◽  
Vortex Strength ◽  
Spacing Ratio ◽  
Vortex Streets ◽  
Dimensional Parameters ◽  
Initial Spacing ◽  
Analytical Expressions

Semi-infinite double rows of vortices are used to study the periodic wake of both oscillating and stationary two-dimensional bodies immersed in a uniform incompressible stream. Analytical expressions for the induced Velocities on the body, for trails with constant spacing, which are valid for small values of the oscillation amplitude are presented while, for the general case of vortex shedding, an iterative procedure for the representation of trails of variable spacing is developed and used. Vortex streets due to oscillating bodies are obtained as a function of three non-dimensional parameters: the Strouhal number (initial spacing ratio), a non-dimensional vortex strength and the downstream spacing ratio. Criteria establishing when such trails are expected to widen, become narrow or stay of constant width are presented, as well as expressions for the induced velocities.The trails and their induced velocities enable the calculation of the vortex strength from measurable quantities. Thus they can serve as a method for estimating the hydrodynamic forces on the airfoil due to large amplitude oscillations, such as those observed in the propulsive movements of fish and cetaceans, as well as the small amplitude oscillations due to hydroelastic interactions.

scholarly journals Bayesian Inference for 3D Volumetric Heat Sources Reconstruction from Surfacic IR Imaging

2020 ◽  
Vol 10 (5) ◽  
pp. 1607
Author(s):  
Marie-Marthe Groz ◽  
Emmanuelle Abisset-Chavanne ◽  
Anissa Meziane ◽  
Alain Sommier ◽  
Christophe Pradère
Keyword(s):  
Heat Source ◽  
Temperature Response ◽  
Optical Excitation ◽  
Thermal Characterization ◽  
Transient Temperature ◽  
Geometrical Shape ◽  
Heat Sources ◽  
Destructive Testing ◽  
Joule Effect ◽  
Ir Camera

The domain of non-destructive testing (NDT) or thermal characterization is currently often done by using contactless methods based on the use of an IR camera to monitor the transient temperature response of a system or sample warmed by using any heat source. Though many techniques use optical excitation (flash lamps, lasers, etc.), some techniques use volumetric sources such as acoustic or induction waves. In this paper, we propose a new inverse processing method, which allows for the estimation of 3D fields of heat sources from surface temperature measurements. This method should be associated with volumetric heat source generation. To validate the method, a volumetric source was generated by the Joule effect in a homogeneous PVC sample using an electrical thin cylindrical wire molded in the material. The inverse processing allows us to retrieve the depth of the wire and its geometrical shape and size. This tool could be a new procedure for retrieving 3D defects on NDT.

An Experimental Study of Transient Heat Transfer From Discrete Heat Sources in Water Cooled Vertical Rectangular Channel

2004 ◽  
Vol 127 (3) ◽  
pp. 193-199 ◽  
Author(s):  
H. Bhowmik ◽  
K. W. Tou
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Heat Source ◽  
Rectangular Channel ◽  
Convection Heat Transfer ◽  
Uniform Heat Flux ◽  
Heat Sources ◽  
Discrete Heat Sources ◽  
Wide Range ◽  
Transfer Behavior

Experiments are performed to study the single-phase transient forced convection heat transfer on an array of 4×1 flush-mounted discrete heat sources in a vertical rectangular channel during the pump-on transient operation. Water is the coolant media and the flow covers the wide range of laminar flow regime with Reynolds number, based on heat source length, from 800 to 2625. The applied uniform heat flux ranges from 1 to 7W∕cm2. For flush-mounted heaters the heat transfer characteristics are studied and correlations are presented for four chips as well as for overall data in the transient regime. The experimental results indicate that the heat transfer coefficient is affected strongly by the number of chips and the Reynolds number. Finally the general impacts of heat source protrusions (B=1, 2 mm) on heat transfer behavior of four chips are investigated by comparing the results obtained from flush-mounted (B=0) heaters.

Mixed Convection Heat Transfer From Thermal Sources Mounted on Horizontal and Vertical Surfaces

1990 ◽  
Vol 112 (4) ◽  
pp. 975-987 ◽  
Author(s):  
S. S. Tewari ◽  
Y. Jaluria
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Heat Source ◽  
Mixed Convection ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Finite Width ◽  
Heat Sources ◽  
Wide Range ◽  
Thermal Sources

An experimental study is carried out on the fundamental aspects of the conjugate, mixed convective heat transfer from two finite width heat sources, which are of negligible thickness, have a uniform heat flux input at the surface, and are located on a flat plate in the horizontal or the vertical orientation. The heat sources are wide in the transverse direction and, therefore, a two-dimensional flow circumstance is simulated. The mixed convection parameter is varied over a fairly wide range to include the buoyancy-dominated and the mixed convection regimes. The circumstances of pure natural convection are also investigated. The convective mechanisms have been studied in detail by measuring the surface temperatures and determining the heat transfer coefficients for the two heated strips, which represent isolated thermal sources. Experimental results indicate that a stronger upstream heat source causes an increase in the surface temperature of a relatively weaker heat source, located downstream, by reducing its convective heat transfer coefficient. The influence of the upstream source is found to be strongly dependent on the surface orientation, especially in the pure natural convection and the buoyancy dominated regimes. The two heat sources are found to be essentially independent of each other, in terms of thermal effects, at a separation distance of more than about three strip widths for both the orientations. The results obtained are relevant to many engineering applications, such as the cooling of electronic systems, positioning of heating elements in furnaces, and safety considerations in enclosure fires.

Applying Surface Fitting in the Medical Thermal Texture Maps

2012 ◽  
Vol 263-266 ◽  
pp. 2448-2453
Author(s):  
Fu Li Ye ◽  
Gui Lian Shi
Keyword(s):  
Early Detection ◽  
Heat Source ◽  
Curve Fitting ◽  
Early Detection Of Cancer ◽  
Single Point ◽  
Surface Fitting ◽  
Heat Sources ◽  
Point Heat Source ◽  
Fitting Method ◽  
Fitting In

This paper studies the application of surface fitting technology in medical tomography. In clinical research, in the result of early detection of cancer increasingly critical, the accuracy and efficiency become the most important issues in medical tomography. However, recent research on medical tomography only use curve fitting technology and only can fit single point heat source, which cause the analyzed result not accurate enough and complex the process of medical tomography. To improve the problem, surface fitting technology is applied in medical tomography, and then information of multiple heat sources can be directly fitted out. The experiments have confirmed: using Custom Equation fitting method in the Curve Fitting Toolbox of MATLAB can accurately fit out heats as well as locations of multiple heat sources (information of diseases area). The result improves the accuracy and efficiency of the Tomography and provides the base for the design.

Temperature in Semi-Infinite and Cylindrical Bodies Subjected to Moving Heat Sources and Surface Cooling

1970 ◽  
Vol 92 (3) ◽  
pp. 456-464 ◽  
Author(s):  
N. R. DesRuisseaux ◽  
R. D. Zerkle
Keyword(s):  
Heat Source ◽  
Cylindrical Body ◽  
Heat Sources ◽  
Surface Cooling ◽  
Machining Processes ◽  
Infinite Body ◽  
Entire Surface ◽  
Convective Cooling ◽  
Temperature Distributions ◽  
Analytical Results

The theory of moving heat sources is applied to two models to determine the effect of convective surface cooling on temperature distributions. The models chosen consist of a translating semi-infinite body and a rotating cylindrical body, each having a band heat source acting on a portion of the surface and convective cooling acting over the entire surface. The analytical results can be utilized to predict temperature distributions occurring in certain machining processes or other processes involving heat sources.

The nonlinear problem of a gliding body with gravity

2013 ◽  
Vol 727 ◽  
pp. 132-160 ◽  
Author(s):  
Y. A. Semenov ◽  
G. X. Wu
Keyword(s):  
Free Surface ◽  
Body Surface ◽  
Breaking Waves ◽  
The Body ◽  
Surface Shape ◽  
Parameter Plane ◽  
Hodograph Method ◽  
Wide Range ◽  
Free Surface Shape ◽  
Analytical Expressions

AbstractAnalysis based on the velocity potential free flow theory with the fully nonlinear boundary condition is made for the steady flow generated by a body gliding along a free surface. Employing the integral hodograph method, we derive analytical expressions for the complex velocity and for the derivative of the complex potential with the coordinate of a parameter plane. The boundary value problem is transformed into a system of two integro-differential equations for the velocity modulus on the free surface and for the slope of the wetted body surface in the parameter plane. The same slope and curvature of the free surface and the body surface at the intersection are adopted to determine the separation points of the flow and from the body. Numerical results are provided for a gliding flat plate and a circular cylinder. The pressure distribution along the body and the free surface shape are presented for a wide range of Froude numbers, within the limit for which the solution corresponding to non-breaking waves downstream can be obtained.

Moving Heat Sources in a Half Space: Effect of Source Geometry

2009 ◽  
Author(s):  
Mohsen Akbari ◽  
David Sinton ◽  
Majid Bahrami
Keyword(s):  
Temperature Distribution ◽  
Heat Source ◽  
Half Space ◽  
Source Area ◽  
Heat Sources ◽  
Shape Variation ◽  
Wide Range ◽  
Space Effect ◽  
Moving Plane ◽  
Transient And Steady State

The time dependent temperature distribution due to a moving plane heat source of hyperelliptical geometry is analytically studied in this work. The effect of the heat source shape is investigated starting from the general solution of a moving heat source on a half space. Selecting the square root of the heat source area as a length scale, it is observed that the temperature distribution becomes a weak function of the heat source shape. Variation of temperature field with respect to the source aspect ratio, velocity and depth is studied. The analysis presented in this work is valid for both transient and steady-state conditions. In addition, the hyperellipse formulation provided here covers a wide range of shapes including star, rhombic, ellipse, circle, square, rectangle and rectangle with rounded corners.

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