The Temperature Field Caused by Sphere Inclusion in Dielectric Irradiated by Multi-Pulse Laser

2013 ◽  
Vol 423-426 ◽  
pp. 452-455
Author(s):  
Cai Hua Huang ◽  
Xiao Hua Sun ◽  
Yi Hua Sun
Keyword(s):  
Differential Equation ◽  
Temperature Field ◽  
Heat Conduction ◽  
Finite Difference Method ◽  
Pulse Duration ◽  
Pulse Laser ◽  
Single Pulse ◽  
Inclusion Size ◽  
Equation Of Heat Conduction ◽  
Repetition Interval

The thermal effect caused by absorbing inclusions irradiated by multi-pulse laser is different from that of single pulse laser. The temperature field induced by multi-pulse laser depends markedly on both inclusion size and pulse duration, and repetition interval of pulse. Based on the differential equation of heat conduction, the temperature field caused by single absorbing inclusion is solved by use of finite difference method. The effect of inclusion size, pulse duration and repetition interval of pulse on the evolution of temperature field at the center of inclusion and interface between inclusion and dielectric are discussed qualitatively.

The Temperature Field Caused by Sphere Inclusion in Dielectric Irradiated by Single Pulse Laser

2013 ◽  
Vol 423-426 ◽  
pp. 448-451
Author(s):  
Cai Hua Huang ◽  
Xiao Hua Sun ◽  
Yi Hua Sun
Keyword(s):  
Temperature Field ◽  
Heat Conduction ◽  
Thermal Effect ◽  
Pulse Duration ◽  
Optical Materials ◽  
Laser Intensity ◽  
Single Pulse ◽  
Equation Of Heat Conduction ◽  
Unsteady Heat Conduction ◽  
Main Factor

The thermal effect arisen from absorbing inclusions is the main factor which causes the damage of optical materials or component irradiated by the longer pulse duration laser. The unsteady heat conduction depends markedly on both the thermal properties of inclusions and the parameters of laser. Based on the differential equation of heat conduction, the temperature distribution caused by single absorbing inclusion is solved by use of finite difference method. The effect of the laser intensity and the pulse duration on temperature field is analyzed in detail. The result demonstrates that the smaller size inclusion and the smaller pulse duration cause relative safe thermal effect, consequently, the less probability to be damaged by thermal effect.

scholarly journals Simplified Grinding Temperature Model Study

2019 ◽  
Vol 6 (2) ◽  
pp. a1-a7
Author(s):  
N. V. Lishchenko ◽  
V. P. Larshin ◽  
H. Krachunov
Keyword(s):  
Differential Equation ◽  
Heat Conduction ◽  
Heat Source ◽  
Boundary Conditions ◽  
Grinding Temperature ◽  
Temperature Model ◽  
One Dimensional ◽  
Heating And Cooling ◽  
Equation Of Heat Conduction ◽  
The One

A study of a simplified mathematical model for determining the grinding temperature is performed. According to the obtained results, the equations of this model differ slightly from the corresponding more exact solution of the one-dimensional differential equation of heat conduction under the boundary conditions of the second kind. The model under study is represented by a system of two equations that describe the grinding temperature at the heating and cooling stages without the use of forced cooling. The scope of the studied model corresponds to the modern technological operations of grinding on CNC machines for conditions where the numerical value of the Peclet number is more than 4. This, in turn, corresponds to the Jaeger criterion for the so-called fast-moving heat source, for which the operation parameter of the workpiece velocity may be equivalently (in temperature) replaced by the action time of the heat source. This makes it possible to use a simpler solution of the one-dimensional differential equation of heat conduction at the boundary conditions of the second kind (one-dimensional analytical model) instead of a similar solution of the two-dimensional one with a slight deviation of the grinding temperature calculation result. It is established that the proposed simplified mathematical expression for determining the grinding temperature differs from the more accurate one-dimensional analytical solution by no more than 11 % and 15 % at the stages of heating and cooling, respectively. Comparison of the data on the grinding temperature change according to the conventional and developed equations has shown that these equations are close and have two points of coincidence: on the surface and at the depth of approximately threefold decrease in temperature. It is also established that the nature of the ratio between the scales of change of the Peclet number 0.09 and 9 and the grinding temperature depth 1 and 10 is of 100 to 10. Additionally, another unusual mechanism is revealed for both compared equations: a higher temperature at the surface is accompanied by a lower temperature at the depth. Keywords: grinding temperature, heating stage, cooling stage, dimensionless temperature, temperature model.

scholarly journals Ultrashort single-pulse laser ablation of stainless steel, aluminium, copper and its dependence on the pulse duration

2021 ◽  
Vol 29 (10) ◽  
pp. 14561
Author(s):  
Jan Winter ◽  
Maximilian Spellauge ◽  
Jens Hermann ◽  
Constanze Eulenkamp ◽  
Heinz P. Huber ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Laser Ablation ◽  
Pulse Duration ◽  
Pulse Laser ◽  
Pulse Laser Ablation ◽  
Single Pulse ◽  
Aluminium Copper

Research on Thermal Effect Caused by Absorbing Inclusion in Dielectric Irradiated by Pulse Laser

2015 ◽  
Vol 713-715 ◽  
pp. 231-234
Author(s):  
Cai Hua Huang ◽  
Xiao Hua Sun ◽  
Yi Hua Sun ◽  
Jun Zou
Keyword(s):  
Thermal Effect ◽  
Pulse Duration ◽  
Pulse Laser ◽  
Critical Radius ◽  
Peak Temperature ◽  
Repetition Interval

The thermal effect caused by absorbing inclusion irradiated by pulse laser is affected by size of inclusions, pulse duration, repetition interval and number of pulse laser. The temperature both in the center of inclusion and the interface between inclusion and dielectric increases firstly with the increase of the size of inclusion, then trends to a constant value when the size is over the critical radius. Pulse duration and repetition interval of pulse change the energy acumulation in inclusion then have influence on the peak temperature in the center and interface. The temperature fluctuates periodically but the overall assumes the trend of increase.

The Wave Propagation Equation of Heat Conduction in Crystal

2010 ◽  
Author(s):  
Weimin Huang
Keyword(s):  
Wave Propagation ◽  
Temperature Field ◽  
Heat Conduction ◽  
Kinetic Energy ◽  
Gradient Field ◽  
Propagation Equation ◽  
Hamilton Function ◽  
Thermal Oscillation ◽  
Equation Of Heat Conduction ◽  
Oscillation Equation

This paper advances a new statistic way for localized particles of crystal by space configuration of momentum restricting on order of position and proposes the concept of macroscopic “thermal oscillation” in gradient field of temperature. The oscillation equation of “thermal oscillaton” and the wave propagation equation in temperature field of crystal are deduced from the Hamilton function with the oscillation kinetic energy and thermal potential energy. The finite propagation velocity of heat is analytically discussed.

Research on the Variation of Average Temperature of Heat Conduction Process under the Second Boundary Condition

2012 ◽  
Vol 562-564 ◽  
pp. 1951-1954
Author(s):  
Yong Yan Wang ◽  
Chuan Qi Su ◽  
Hong Cai Zheng ◽  
Nan Qin ◽  
Jia Bin Shi
Keyword(s):  
Differential Equation ◽  
Boundary Condition ◽  
Heat Conduction ◽  
Integral Form ◽  
Energy Principle ◽  
Conservation Of Energy ◽  
Average Temperature ◽  
Equation Of Heat Conduction ◽  
Heat Conduction Process ◽  
Adiabatic Boundary Condition

The variation law of the average temperature with time in general case is derived by the differential equation of heat conduction which it is the reflection of the conservation of energy principle. The expression of the average temperature under the second boundary condition is given by the integral form of initial and boundary conditions. And what can be also derived are that the average temperature has a linear relationship with time when the boundary heat flux is constant, and it does not change with time under the adiabatic boundary condition.

scholarly journals Application of Jacobi Polynomial and Multivariable Aleph- Function in Heat Conduction in Non-Homogeneous Moving Rectangular Parallelepiped

2021 ◽  
Vol 45 (03) ◽  
pp. 439-448
Author(s):  
DINESH KUMAR ◽  
FRÉDÉRIC AYANT
Keyword(s):  
Differential Equation ◽  
Heat Conduction ◽  
Temperature Distribution ◽  
Jacobi Polynomial ◽  
Rectangular Parallelepiped ◽  
Equation Of Heat Conduction ◽  
Function Of Two Variables

The present paper deals with an application of Jacobi polynomial and multivariable Aleph-function to solve the differential equation of heat conduction in non-homogeneous moving rectangular parallelepiped. The temperature distribution in the parallelepiped, moving in a direction of the length (x-axis) between the limits x = −1 and x = 1 has been considered. The conductivity and the velocity have been assumed to be variables. We shall see two particular cases and the cases concerning Aleph-function of two variables and the I-function of two variables.

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