Entropy generation rate during laser pulse heating: Effect of laser pulse parameters on entropy generation rate

2008 ◽  
Vol 46 (1) ◽  
pp. 27-33 ◽  
Author(s):  
H. Al-Qahtani ◽  
B.S. Yilbas
2016 ◽  
Vol 94 (1) ◽  
pp. 130-138 ◽  
Author(s):  
H. Ali ◽  
B.S. Yilbas ◽  
A.Y. Al-Dweik

Laser short-pulse heating of a nano-size wire is considered and entropy generation rate is predicted during the heating pulse. The analytical solution of the heat equation is obtained using the Lie point symmetry for the laser short-pulse heating. The nano-size wire is assumed to be symmetric along its y-axis. Laser pulse intensity is considered to be Gaussian at the irradiated surface while the exponential decay of the laser pulse is incorporated in the time domain. It is found that surface temperature variation in the lattice subsystem almost follows the laser pulse intensity distribution at the surface. Entropy generation rate attains low values along the symmetry axis and it increases considerably in the region of the nano-size wire edges. This behavior is associated with the temperature gradient, which attains high values in the region close to the nano-size wire edge.


2013 ◽  
Vol 98 (12) ◽  
pp. 2497-2502 ◽  
Author(s):  
Stephen F. Bartolucci ◽  
Karen E. Supan ◽  
Jeffrey S. Wiggins ◽  
Lawrence LaBeaud ◽  
Jeffrey M. Warrender

1994 ◽  
Vol 7 (3) ◽  
pp. 175-188 ◽  
Author(s):  
Taiqing Qiu ◽  
Chang-Lin Tien ◽  
Mark A. Shannon ◽  
Richard E. Russo

Author(s):  
Harshad Sanjay Gaikwad ◽  
Pranab Kumar Mondal ◽  
Dipankar Narayan Basu ◽  
Nares Chimres ◽  
Somchai Wongwises

In this article, we perform an entropy generation analysis for the micro channel heat sink applications where the flow of fluid is actuated by combined influences of applied pressure gradient and electric field under electrical double layer phenomenon. The upper and lower walls of the channels are kept at different constant temperatures. The temperature-dependent viscosity of the fluid is considered and hence the momentum equation and energy equations are coupled in this study. Also, a hydrodynamic slip condition is employed on the viscous dissipation. For complete analysis of the entropy generation, we use a perturbation approach with lubrication approximation. In this study, we discuss the results depicting variations in the velocity and temperature distributions and their effect on local entropy generation rate and Bejan number in the system. It can be summarized from this analysis that the enhanced velocity gradients in the flow field due to combined effect of temperature-dependent viscosity and Joule heating and viscous dissipative effects, leads to an enhancement in the local entropy generation rate in the system.


Author(s):  
Wei Wang ◽  
Jun Wang ◽  
Xiao-Pei Yang ◽  
Yan-Yan Ding

Abstract An entropy analysis and design optimization methodology is combined with airfoil shape optimization to demonstrate the impact of entropy generation on aerodynamics designs. In the work herein, the entropy generation rate is presented as an extra design objective along with lift-drag ratio, while the lift coefficient is the constraint. Model equation, which calculates the local entropy generation rate in turbulent flows, is derived by extending the Reynolds-averaging of entropy balance equation. The class-shape function transform (CST) parametric method is used to model the airfoil configuration and combine the radial basis functions (RBFs) based mesh deformation technique with flow solver to compute the quantities such as lift-drag ratio and entropy generation at the design condition. From the multi-objective solutions which represent the best trade-offs between the design objectives, one can select a set of airfoil shapes with a low relative energy cost and with improved aerodynamic performance. It can be concluded that the methodology of entropy generation analysis is an effective tool in the aerodynamic optimization design of airfoil shape with the capability of determining the amount of energy cost.


Carbon ◽  
2002 ◽  
Vol 40 (11) ◽  
pp. 2031-2034 ◽  
Author(s):  
M Joseph ◽  
N Sivakumar ◽  
P Manoravi

Sign in / Sign up

Export Citation Format

Share Document