scholarly journals Transient Analysis of Silicon Devices Using the Hydrodynamic Model

VLSI Design ◽  
1998 ◽  
Vol 6 (1-4) ◽  
pp. 283-286 ◽  
Author(s):  
Luigi Colalongo ◽  
Marina Valdinoci ◽  
Antonio Gnudi ◽  
Massimo Rudan
Keyword(s):  
Hydrodynamic Model ◽  
Transient Analysis ◽  
Velocity Overshoot ◽  
Silicon Devices ◽  
Switching Behaviour ◽  
Submicron Devices ◽  
Transient Case ◽  
Drain Region ◽  
Ballistic Diode ◽  
Mos Device

The analysis of the switching behaviour of submicron devices brings about the necessity of extending the solution of the hydrodynamic model to the transient case. The implementation of such model has been carried out and a few examples of simulation are presented here, showing the velocity-overshoot of a ballistic diode and the temperature spread in the drain region of a realistic MOS device.

Transient Analysis of Air Flow in a Channel for Unconventional Radiator

2018 ◽  
Author(s):  
Wahidul Islam ◽  
Jobaidur Rahman Khan
Keyword(s):  
Steady State ◽  
Transient Analysis ◽  
Air Flow ◽  
Axial Flow ◽  
Flow Distribution ◽  
Transient State ◽  
Short Channel ◽  
Final Design ◽  
Uniform Flow Distribution ◽  
Transient Case

A number of cars are found to have an unconventional radiator. The radiator is placed at the back of the car instead of front, for which the radiator does not get the incoming airflow to cool the engine down and the engine gets overheated very easily. In order to deal with this problem, a channel has been mounted at the top of the vehicle to navigate incoming air flow and direct it through the radiator to cool down the engine. Three channels are tested computationally with three different lengths, which indicates the different way of studying this problem. Transient state analysis has been performed. Each length has its own characteristics. For example, a longer channel creates little circulation but more axial flow towards the radiator, while shorter channel creates smooth but less axial flow towards the radiator. All these cases in the steady state have the same domain and will have similar inlet variables like velocity, shape, size, and position. A transient state simulation, most of the circulation were shown in the left-mid plane especially in longer channels. Transient state gives more uniform flow distribution. For longer channels in transient case, the flow is symmetric and smooth, while the flow is not found symmetric for short channel. The results were all made and developed in ANSYS for the final design where the data were simulated.

scholarly journals A Hydrodynamic Model for Transport in Semiconductors without Free Parameters

VLSI Design ◽  
1998 ◽  
Vol 8 (1-4) ◽  
pp. 527-532 ◽  
Author(s):  
P. Falsaperla ◽  
M. Trovato
Keyword(s):  
Monte Carlo ◽  
Distribution Function ◽  
Maximum Principle ◽  
Energy Flux ◽  
Hydrodynamic Model ◽  
Entropy Maximum ◽  
Monte Carlo Computation ◽  
Submicron Devices ◽  
Stress Energy ◽  
Free Parameters

We derive, using the Entropy Maximum Principle, an expression for the distribution function of carriers as a function of a set of macroscopic quantities (density, velocity, energy, deviatoric stress, energy flux). Given the distribution function, we obtain, for these macroscopic quantities, a hydrodynamic model in which all the constitutive functions (fluxes and collisional productions) are explicitely computed starting from their kinetic expressions. We have applied our model to the simulation of some onedimensional submicron devices in a temperature range of 77–300 K, obtaining results comparable with Monte Carlo. Computation times are of order of few seconds for a picosecond of simulation.

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