3-D Inverse Heat Transfer in a Composite Target Subject to High-Energy Laser Irradiation

2011 ◽  
Author(s):  
Jianhua Zhou ◽  
Yuwen Zhang ◽  
J. K. Chen ◽  
Z. C. Feng
Keyword(s):  
Heat Transfer ◽  
Gas Flow ◽  
Heat Conduction Problem ◽  
High Energy ◽  
Inverse Heat Conduction Problem ◽  
Back Surface ◽  
Composite Target ◽  
Inverse Heat Transfer ◽  
Energy Laser ◽  
High Energy Laser

A new numerical model is developed to simulate the 3-D inverse heat transfer in a composite target with pyrolysis and outgassing effects. The gas flow channel size and gas addition velocity are determined by the rate equation of decomposition chemical reaction. The thermophysical properties of the composite considered are temperature-dependent. A nonlinear conjugate gradient method (CGM) is applied to solve the inverse heat conduction problem for high-energy laser-irradiated composite targets. It is shown that the front-surface temperature can be recovered with satisfactory accuracy based on the temperature/heat flux measurements on the back surface and the temperature measurement at an interior plane.

Three-Dimensional Inverse Heat Transfer in a Composite Target Subject to High-Energy Laser Irradiation

2012 ◽  
Vol 134 (11) ◽  
Author(s):  
Jianhua Zhou ◽  
Yuwen Zhang ◽  
J. K. Chen ◽  
Z. C. Feng
Keyword(s):  
Heat Transfer ◽  
Gas Flow ◽  
Heat Conduction Problem ◽  
High Energy ◽  
Inverse Heat Conduction Problem ◽  
Back Surface ◽  
Composite Target ◽  
Inverse Heat Transfer ◽  
Energy Laser ◽  
High Energy Laser

A new numerical model is developed to simulate the 3D inverse heat transfer in a composite target with pyrolysis and outgassing effects. The gas flow channel size and gas addition velocity are determined by the rate equation of decomposition chemical reaction. The thermophysical properties of the composite considered are temperature-dependent. A nonlinear conjugate gradient method (CGM) is applied to solve the inverse heat conduction problem for high-energy laser-irradiated composite targets. It is shown that the front-surface temperature can be recovered with satisfactory accuracy based on the temperature/heat flux measurements on the back surface and the temperature measurement at an interior plane.

scholarly journals Solving the inverse heat conduction problem using NVLink capable Power architecture

2017 ◽  
Vol 3 ◽  
pp. e138 ◽  
Author(s):  
Sándor Szénási
Keyword(s):  
Heat Transfer ◽  
Data Transfer ◽  
Heat Conduction Problem ◽  
Inverse Heat Conduction Problem ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Inverse Heat Transfer ◽  
Long Time ◽  
History Of ◽  
The Cost

The accurate knowledge of Heat Transfer Coefficients is essential for the design of precise heat transfer operations. The determination of these values requires Inverse Heat Transfer Calculations, which are usually based on heuristic optimisation techniques, like Genetic Algorithms or Particle Swarm Optimisation. The main bottleneck of these heuristics is the high computational demand of the cost function calculation, which is usually based on heat transfer simulations producing the thermal history of the workpiece at given locations. This Direct Heat Transfer Calculation is a well parallelisable process, making it feasible to implement an efficient GPU kernel for this purpose. This paper presents a novel step forward: based on the special requirements of the heuristics solving the inverse problem (executing hundreds of simulations in a parallel fashion at the end of each iteration), it is possible to gain a higher level of parallelism using multiple graphics accelerators. The results show that this implementation (running on 4 GPUs) is about 120 times faster than a traditional CPU implementation using 20 cores. The latest developments of the GPU-based High Power Computations area were also analysed, like the new NVLink connection between the host and the devices, which tries to solve the long time existing data transfer handicap of GPU programming.

scholarly journals Thermal effects of high energy and ultrafast lasers

2015 ◽  
Author(s):  
◽  
Nazia Afrin
Keyword(s):  
Heat Transfer ◽  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Heat Transport ◽  
Phonon Scattering ◽  
Heated Surface ◽  
High Energy ◽  
Electron Interaction ◽  
Energy Laser ◽  
High Energy Laser

Heat transfer describes the exchange of thermal energy, between physical systems depending on the temperature and pressure, by dissipating heat. The fundamental modes of heat transfer are conduction or diffusion, convection and radiation. Heat and mass transfer are kinetic processes that may occur and be studied separately or jointly. Studying them apart is simpler, but both processes are modeled by similar mathematical equation in the case of diffusion and convection. There are complex problems where heat and mass transfer processes are combined with chemical reactions, as in combustion. The resulting behavior of heat transport in microscale will be very different from macroscale heat transfer based on the averages taken over hundreds of thousands of grains (in space) and collision (in time). From the microscopic point of view, the process of heat transport is governed by phonon-electron interaction in metallic films and by phonon scattering in dielectric films, insulators and semi-conductors. For extremely heated surfaces by high energy laser pulse, it is very difficult to measure temperature of flux at the heated surface because of the unendurable capacity of the conventional sensors. Laser is the tool of choice when drill holes ranging in diameter from several millimeters to less than one micro-meter. Instead of having advanced melting and resolidification modeling process recently, the inherent uncertainties of the input parameters can directly cause unstable characteristics of the output results which means the parametric uncertainties may influence the characteristics of the phase change processes (melting and resolidification) which will affect the predictions of interfacial properties i.e., temperature, velocity and mainly the location of solid-liquid interface. All of those processes can be considered under high energy laser interaction with materials.

scholarly journals Database for Research Projects to Solve the Inverse Heat Conduction Problem

Data ◽  
2019 ◽  
Vol 4 (3) ◽  
pp. 90
Author(s):  
Sándor Szénási ◽  
Imre Felde
Keyword(s):  
Heat Transfer ◽  
Machine Learning ◽  
Transfer Problem ◽  
Heat Conduction Problem ◽  
Inverse Heat Conduction Problem ◽  
Training Data ◽  
Work Piece ◽  
Heuristic Search Algorithms ◽  
Inverse Heat Transfer ◽  
Inverse Heat Transfer Problem

To achieve the optimal performance of an object to be heat treated, it is necessary to know the value of the Heat Transfer Coefficient (HTC) describing the amount of heat exchange between the work piece and the cooling medium. The prediction of the HTC is a typical Inverse Heat Transfer Problem (IHCP), which cannot be solved by direct numerical methods. Numerous techniques are used to solve the IHCP based on heuristic search algorithms having very high computational demand. As another approach, it would be possible to use machine-learning methods for the same purpose, which are capable of giving prompt estimations about the main characteristics of the HTC function. As known, a key requirement for all successful machine-learning projects is the availability of high quality training data. In this case, the amount of real-world measurements is far from satisfactory because of the high cost of these tests. As an alternative, it is possible to generate the necessary databases using simulations. This paper presents a novel model for random HTC function generation based on control points and additional parameters defining the shape of curve segments. As an additional step, a GPU accelerated finite-element method was used to simulate the cooling process resulting in the required temporary data records. These datasets make it possible for researchers to develop and test their IHCP solver algorithms.

Alpha-Lamp Integration (ALI) program progressing toward integrated High Energy Laser (HEL) test

1997 ◽  
Author(s):  
David Loomis ◽  
Charles Nefzger ◽  
Ben Platt ◽  
David Loomis ◽  
Charles Nefzger ◽  
...  
Keyword(s):  
High Energy ◽  
Energy Laser ◽  
High Energy Laser

Development of High-Energy Laser for FIREX Program

2005 ◽  
Vol 33 (Supplement) ◽  
pp. 55-56
Author(s):  
N. Miyanaga ◽  
H. Azechi ◽  
K.A. Tanaka ◽  
T. Jitsuno ◽  
H. Shiraga ◽  
...  
Keyword(s):  
High Energy ◽  
Energy Laser ◽  
High Energy Laser

Structural transformations of carbon black by high-energy laser and electron irradiation

2015 ◽  
Vol 10 (9-10) ◽  
pp. 696-700 ◽  
Author(s):  
O. V. Ivashchenko ◽  
M. V. Trenikhin ◽  
Yu. G. Kryazhev ◽  
B. P. Tolochko ◽  
V. S. Eliseev ◽  
...  
Keyword(s):  
Carbon Black ◽  
Electron Irradiation ◽  
High Energy ◽  
Structural Transformations ◽  
Energy Laser ◽  
High Energy Laser
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