Developing high-performance reflective coatings for the tunable filter and the high-order interferometer of the 3D-NTT

2008 ◽  
Author(s):  
Marie-Maude de Denus-Baillargeon ◽  
La"titia Abel-Tibérini ◽  
Michel Lequime ◽  
Claude Carignan ◽  
Benoît Épinat ◽  
...  
Keyword(s):  
High Performance ◽  
Tunable Filter ◽  
High Order ◽  
Reflective Coatings

scholarly journals A massively parallel time-domain coupled electrodynamics–micromagnetics solver

2022 ◽  
pp. 109434202110579
Author(s):  
Zhi Yao ◽  
Revathi Jambunathan ◽  
Yadong Zeng ◽  
Andrew Nonaka
Keyword(s):  
Time Domain ◽  
High Performance ◽  
Tunable Filter ◽  
Coupling Scheme ◽  
Temporal Coupling ◽  
Electromagnetic Waveguide ◽  
Plasma Wakefield Accelerator ◽  
Plasma Wakefield ◽  
Wakefield Accelerator ◽  
Difference Time

We present a high-performance coupled electrodynamics–micromagnetics solver for full physical modeling of signals in microelectronic circuitry. The overall strategy couples a finite-difference time-domain approach for Maxwell’s equations to a magnetization model described by the Landau–Lifshitz–Gilbert equation. The algorithm is implemented in the Exascale Computing Project software framework, AMReX, which provides effective scalability on manycore and GPU-based supercomputing architectures. Furthermore, the code leverages ongoing developments of the Exascale Application Code, WarpX, which is primarily being developed for plasma wakefield accelerator modeling. Our temporal coupling scheme provides second-order accuracy in space and time by combining the integration steps for the magnetic field and magnetization into an iterative sub-step that includes a trapezoidal temporal discretization for the magnetization. The performance of the algorithm is demonstrated by the excellent scaling results on NERSC multicore and GPU systems, with a significant (59×) speedup on the GPU using a node-by-node comparison. We demonstrate the utility of our code by performing simulations of an electromagnetic waveguide and a magnetically tunable filter.

scholarly journals Parallel 3-D marine controlled-source electromagnetic modelling using high-order tetrahedral Nédélec elements

2019 ◽  
Vol 219 (1) ◽  
pp. 39-65
Author(s):  
Octavio Castillo-Reyes ◽  
Josep de la Puente ◽  
Luis Emilio García-Castillo ◽  
José María Cela
Keyword(s):  
High Performance ◽  
Computational Cost ◽  
Low Frequency ◽  
Computation Time ◽  
Multiple Scale ◽  
High Order ◽  
Physical Parameters ◽  
Adaptive Meshing ◽  
Controlled Source ◽  
High Order Schemes

SUMMARY We present a parallel and high-order Nédélec finite element solution for the marine controlled-source electromagnetic (CSEM) forward problem in 3-D media with isotropic conductivity. Our parallel Python code is implemented on unstructured tetrahedral meshes, which support multiple-scale structures and bathymetry for general marine 3-D CSEM modelling applications. Based on a primary/secondary field approach, we solve the diffusive form of Maxwell’s equations in the low-frequency domain. We investigate the accuracy and performance advantages of our new high-order algorithm against a low-order implementation proposed in our previous work. The numerical precision of our high-order method has been successfully verified by comparisons against previously published results that are relevant in terms of scale and geological properties. A convergence study confirms that high-order polynomials offer a better trade-off between accuracy and computation time. However, the optimum choice of the polynomial order depends on both the input model and the required accuracy as revealed by our tests. Also, we extend our adaptive-meshing strategy to high-order tetrahedral elements. Using adapted meshes to both physical parameters and high-order schemes, we are able to achieve a significant reduction in computational cost without sacrificing accuracy in the modelling. Furthermore, we demonstrate the excellent performance and quasi-linear scaling of our implementation in a state-of-the-art high-performance computing architecture.

scholarly journals An Improved Super-Twisting High-Order Sliding Mode Observer for Sensorless Control of Permanent Magnet Synchronous Motor

Energies ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 6047
Author(s):  
Yujiao Zhao ◽  
Haisheng Yu ◽  
Shixian Wang
Keyword(s):  
Permanent Magnet ◽  
High Performance ◽  
Sliding Mode ◽  
Sensorless Control ◽  
Permanent Magnet Synchronous Motor ◽  
High Order ◽  
Sliding Mode Observer ◽  
Estimation Accuracy ◽  
Permanent Magnet Synchronous Motors ◽  
Rotor Position

This article presents an improved super-twisting high-order sliding mode observer for permanent magnet synchronous motors to achieve high-performance sensorless control. The proposed observer is able to simultaneously estimate rotor position and speed, as well as track parameter disturbances online. Then, according to the back-EMF model, the sensorless observer is further constructed to improve the estimation effect. The estimated rotor position and speed are used to replace the actual values detected by the sensor, and the estimated parameter disturbances are considered as feedback values to compensate the command voltage. In this way, not only is the estimation accuracy improved, but the robustness against uncertainties is also enhanced. Simulation and experimental results show that the proposed observer can effectively track the rotor position and speed and obtain good dynamic and steady-state performance.

On the Effect of Inflow Disturbances on the Flow Past a Linear LPT Vane Using Spectral/hp Element Methods

2019 ◽  
Author(s):  
Andrea Cassinelli ◽  
Hui Xu ◽  
Francesco Montomoli ◽  
Paolo Adami ◽  
Raul Vazquez Diaz ◽  
...  
Keyword(s):  
High Performance ◽  
Leading Edge ◽  
High Order ◽  
Software Framework ◽  
Analysis Tool ◽  
Suction Surface ◽  
Present Contribution ◽  
Analysis And Design ◽  
Transition Mechanism ◽  
Moderate Reynolds Number

Abstract The recent development and increasing integration of high performance computing, scale resolving CFD and high order unstructured methods offers a potential opportunity to deliver a simulation-based capability (i.e. virtual) for aerodynamic research, analysis and design of industrial relevant problems in the near future. In particular, the tendency towards high order spectral/hp element methods is motivated by their desirable dispersion-diffusion properties, that are combined to accuracy and flexibility for complex geometries. Previous work from the Authors focused on developing guidelines for the use of these methods as a virtual cascade for turbomachinery applications. Building on such experiments, the present contribution analyzes the performance of a representative industrial cascade at moderate Reynolds number with various levels and types of inflow disturbances, adopting the incompressible Navier-Stokes solver implemented in the Nektar++ software framework. The introduction of a steady/unsteady spanwise-nonuniform momentum forcing in the leading edge region was tested, to break the flow symmetry upstream of the blade and investigate the change in transition mechanism in the aft portion of the suction surface. To provide a systematic synthetic turbulence generation tool, a parallelised version of Davidson’s method is incorporated and applied for the first time in the software framework to a low pressure turbine vane. The clean results of the cascade are compared to various levels of momentum forcing and inflow turbulence, looking at blade wall distributions, wake profiles and boundary layer parameters. Low levels of background disturbances are found to improve the agreement with experimental data. The results support the confidence for using high order spectral methods as a standalone performance analysis tool but, at the same time, underline the sensitivity at these flow regimes to disturbances or instabilities in the real environment when comparing to rig data.

Sign in / Sign up

Export Citation Format

Share Document