Numerical Simulation for the Effect of Wall Material on Near Wall Conductivity in Hall Thrusters

2010 ◽  
Vol 29-32 ◽  
pp. 519-524
Author(s):  
Zhi Wen Wu ◽  
Shu Shu ◽  
Da Ren Yu ◽  
Xiang Yang Liu ◽  
Ning Fei Wang
Keyword(s):  
High Performance ◽  
Channel Wall ◽  
Secondary Electron Emission ◽  
Potential Drop ◽  
Wall Material ◽  
Hall Thrusters ◽  
Wall Conductivity ◽  
Simulation Results ◽  
Absolute Potential ◽  
Near Wall

The wall material plays an important role for the electron current due to near wall conductivity in Hall Thrusters. A Monte Carlo method combined with a one dimensional steady sheath model is presented and is applied to simulate the electron conductive current due to near wall conductivity for the different channel wall materials of Hall thruster. The simulation results show that the higher the secondary electron emission (SEE) coefficient of the channel wall material is, the greater the electron conductive current is. Based on the simulation, a physical explanation is given from the viewpoint of near wall conductivity. For the channel wall material with low SEE coefficient, the secondary electrons taking part in the near wall conductivity becomes less. In addition, the absolute potential drop in the sheath near the wall increases, which means that the sheath can stop more electrons from colliding with the channel wall. And consequently the electron conductive current due to near wall conductivity is much less. The situation is vice verse for the channel wall material with high SEE coefficient. The simulation results are qualitatively in accordance with the experiments. The results can help to choose and design the wall material of the Hall Thrusters with a high performance.

The Effect of Magnetic Mirror on Near Wall Conductivity in Hall Thrusters

2008 ◽  
Vol 48 (8) ◽  
pp. 543-554 ◽  
Author(s):  
D. Yu ◽  
H. Liu ◽  
Y. Cao ◽  
H. Fu
Keyword(s):  
Magnetic Mirror ◽  
Hall Thrusters ◽  
Wall Conductivity ◽  
Near Wall

Wall material effects in stationary plasma thrusters. II. Near-wall and in-wall conductivity

2003 ◽  
Vol 10 (10) ◽  
pp. 4137-4152 ◽  
Author(s):  
S. Barral ◽  
K. Makowski ◽  
Z. Peradzyński ◽  
N. Gascon ◽  
M. Dudeck
Keyword(s):  
Wall Material ◽  
Wall Conductivity ◽  
Stationary Plasma ◽  
Plasma Thrusters ◽  
Stationary Plasma Thrusters ◽  
Near Wall

Effect of oscillating sheath on near-wall conductivity in Hall thrusters

2007 ◽  
Vol 14 (6) ◽  
pp. 064505 ◽  
Author(s):  
Daren Yu ◽  
Hong Li ◽  
Zhiwen Wu ◽  
Wei Mao
Keyword(s):  
Hall Thrusters ◽  
Wall Conductivity ◽  
Near Wall

scholarly journals 3D Simulation-Based Acoustic Wave Resonator Analysis and Validation Using Novel Finite Element Method Software

Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2715
Author(s):  
Ruth Yadira Vidana Morales ◽  
Susana Ortega Cisneros ◽  
Jose Rodrigo Camacho Perez ◽  
Federico Sandoval Ibarra ◽  
Ricardo Casas Carrillo
Keyword(s):  
Finite Element ◽  
High Performance ◽  
Cloud Services ◽  
3D Simulation ◽  
3D Simulations ◽  
Acoustic Resonators ◽  
Analysis And Design ◽  
Wave Resonator ◽  
Film Bulk ◽  
Simulation Results

This work illustrates the analysis of Film Bulk Acoustic Resonators (FBAR) using 3D Finite Element (FEM) simulations with the software OnScale in order to predict and improve resonator performance and quality before manufacturing. This kind of analysis minimizes manufacturing cycles by reducing design time with 3D simulations running on High-Performance Computing (HPC) cloud services. It also enables the identification of manufacturing effects on device performance. The simulation results are compared and validated with a manufactured FBAR device, previously reported, to further highlight the usefulness and advantages of the 3D simulations-based design process. In the 3D simulation results, some analysis challenges, like boundary condition definitions, mesh tuning, loss source tracing, and device quality estimations, were studied. Hence, it is possible to highlight that modern FEM solvers, like OnScale enable unprecedented FBAR analysis and design optimization.

scholarly journals Optimization of Dynamic Task Location within a Manipulator’s Workspace for the Utilization of the Minimum Required Joint Torques

Electronics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 288
Author(s):  
Adam Wolniakowski ◽  
Charalampos Valsamos ◽  
Kanstantsin Miatliuk ◽  
Vassilis Moulianitis ◽  
Nikos Aspragathos
Keyword(s):  
High Performance ◽  
Human Robot Interaction ◽  
Optimal Position ◽  
End Effector ◽  
Joint Torques ◽  
Dynamic Task ◽  
Arbitrary Position ◽  
Simulation Results ◽  
Set Up ◽  
Task Placement

The determination of the optimal position of a robotic task within a manipulator’s workspace is crucial for the manipulator to achieve high performance regarding selected aspects of its operation. In this paper, a method for determining the optimal task placement for a serial manipulator is presented, so that the required joint torques are minimized. The task considered comprises the exercise of a given force in a given direction along a 3D path followed by the end effector. Given that many such tasks are usually conducted by human workers and as such the utilized trajectories are quite complex to model, a Human Robot Interaction (HRI) approach was chosen to define the task, where the robot is taught the task trajectory by a human operator. Furthermore, the presented method considers the singular free paths of the manipulator’s end-effector motion in the configuration space. Simulation results are utilized to set up a physical execution of the task in the optimal derived position within a UR-3 manipulator’s workspace. For reference the task is also placed at an arbitrary “bad” location in order to validate the simulation results. Experimental results verify that the positioning of the task at the optimal location derived by the presented method allows for the task execution with minimum joint torques as opposed to the arbitrary position.

An Offset Reduction Technique for Latch Type Sense Amplifier in High Performance and High Density SRAM

2012 ◽  
Vol 542-543 ◽  
pp. 769-774
Author(s):  
Qun Ling Yu ◽  
Na Bai ◽  
Yan Zhou ◽  
Rui Xing Li ◽  
Jun Ning Chen ◽  
...  
Keyword(s):  
High Performance ◽  
Circuit Simulation ◽  
Cmos Technology ◽  
Optimal Operation ◽  
Reduction Technique ◽  
Total Speed ◽  
Sense Amplifier ◽  
Simulation Results ◽  
A New Technique ◽  
Total Energy Dissipation

A new technique for reducing the offset of latch-type sense amplifier has been proposed and effect of enable signal voltage upon latch-type sense amplifier offset in SRAM has been investigated in this paper. Circuit simulation results on both StrongARM and Double-tail topologies show that the standard deviation of offset can be reduced by 31.23% (StrongARM SA) and 25.2% (Double-tail SA) , respectively, when the voltage of enable signal reaches 0.6V in TSMC 65nm CMOS technology. For a column of bit-cell (1024 bit-cell), the total speed is improved by 14.98% (StrongARAM SA) and 22.26% (Double-tail SA) at the optimal operation point separately, and the total energy dissipation is reduced by 30.45% and 29.47% with this scheme.

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