Analysis of Energy Transport Equations at Micro/Nanoscales

Author(s):  
Bekir Sami Yilbas ◽  
Saad Bin Mansoor ◽  
Haider Ali
2020 ◽  
Vol 142 (4) ◽  
Author(s):  
Vladimir Kulish

Abstract In 2000, Kulish and Lage proposed an elegant method, which allows one to obtain analytical (closed-form) solutions to various energy transport problems. The solutions thus obtained are in the form of the Volterra-type integral equations, which relate the local values of an intensive property (e.g., temperature, mass concentration, and velocity) and the corresponding energy flux (e.g., heat flux, mass flux, and shear stress). The method does not require one to solve for the entire domain, and hence, is a nonfield analytical method. Over the past 19 years, the method was shown to be extremely effective when applied to solving numerous energy transport problems. In spite of all these developments, no general theoretical justification of the method was proposed until now. The present work proposes a justification of the procedure behind the method and provides a generalized technique of splitting the differential operators in the energy transport equations.


2008 ◽  
Vol 18 (12) ◽  
pp. 2125-2150 ◽  
Author(s):  
MARKUS BRUNK ◽  
ANSGAR JÜNGEL

A coupled model with optoelectronic semiconductor devices in electric circuits is proposed. The circuit is modeled by differential-algebraic equations derived from modified nodal analysis. The transport of charge carriers in the semiconductor devices (laser diode and photo diode) is described by the energy-transport equations for the electron density and temperature, the drift-diffusion equations for the hole density, and the Poisson equation for the electric potential. The generation of photons in the laser diode is modeled by spontaneous and stimulated recombination terms appearing in the transport equations. The devices are coupled to the circuit by the semiconductor current entering the circuit and by the applied voltage at the device contacts, coming from the circuit. The resulting time-dependent model is a system of nonlinear partial differential-algebraic equations. The one-dimensional transient transport equations are numerically discretized in time by the backward Euler method and in space by a hybridized mixed finite-element method. Numerical results for a circuit consisting of a single-mode heterostructure laser diode, a silicon photo diode, and a high-pass filter are presented.


1988 ◽  
Vol 31 (5) ◽  
pp. 1288 ◽  
Author(s):  
K. C. Shaing ◽  
Y. Nakamura ◽  
M. Wakatani

1982 ◽  
Vol 25 (6) ◽  
pp. 1007 ◽  
Author(s):  
Young-ping Pao

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