A Tool to Design DC Inductor Using Core Geometry Method

Abstract The supercritical carbon dioxide (SCO2) Brayton cycle is one of the most promising power cycles due to its high efficiency, compactness and environmentally friendliness. The centrifugal compressor is a key component of small and medium SCO2 Brayton cycles, and its efficiency has a significant impact on the cycle efficiency. Since the required electric load of power cycles always fluctuates over the year, the SCO2 compressor will operate away from its design point and the narrow stable operating range of a compressor is always a restriction. In this paper, the variable-geometry method, which refers to the combination of a variable inlet-guide-vanes and variable diffuser vanes is proposed for the operating range extension of SCO2 compressors. A set of one-dimensional (1D) loss correlations has been found to accurately predict various losses of the SCO2 compressor components. Based on the 1D thermodynamic model, two programs with internal MATLAB codes coupled with the NIST REFPROP database have been developed for preliminary optimization design and off-design performance predictions of the variable geometry SCO2 compressor. The contributions from the variable-inlet prewhirl and variable diffuser vanes to the shifts of the surge line and choke line are discussed in this paper. The results show the variable-geometry SCO2 compressor has a superior performance at off-design conditions and a wider operating range.

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Geometry Method of Camera Self-Calibration Based on a Rectangle

Acta Optica Sinica ◽

10.3788/aos201434.1115002 ◽

2014 ◽

Vol 34 (11) ◽

pp. 1115002 ◽

Cited By ~ 3

Author(s):

徐嵩 Xu Song ◽

孙秀霞 Sun Xiuxia ◽

刘希 Liu Xi ◽

蔡鸣 Cai Ming

Keyword(s):

Self Calibration ◽

Geometry Method

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The Jacobi Stability of a Lorenz-Type Multistable Hyperchaotic System with a Curve of Equilibria

International Journal of Bifurcation and Chaos ◽

10.1142/s0218127419500627 ◽

2019 ◽

Vol 29 (05) ◽

pp. 1950062 ◽

Cited By ~ 5

Author(s):

Yuming Chen ◽

Zongbin Yin

Keyword(s):

Differential Geometry ◽

Vector Field ◽

Periodic Orbit ◽

Curvature Tensor ◽

Hyperchaotic System ◽

Geometry Method ◽

Parameter Condition

In this paper, a 4D Lorenz-type multistable hyperchaotic system with a curve of equilibria is investigated by using differential geometry method, i.e. with KCC-theory. Due to the deviation curvature tensor and its eigenvalues, the curve of equilibria of this hyperchaotic system is proved analytically to be Jacobi unstable under a certain parameter condition, and a periodic orbit of this system is proved numerically to be also Jacobi unstable. Furthermore, the dynamics of contravariant vector field near the curve of equilibria and the periodic orbit are studied, respectively, and their results comply absolutely with the above analysis of Jacobi stability.

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A Three-Dimensional Visualization Framework for Underground Geohazard Recognition on Urban Road-Facing GPR Data

ISPRS International Journal of Geo-Information ◽

10.3390/ijgi9110668 ◽

2020 ◽

Vol 9 (11) ◽

pp. 668

Author(s):

Zhenwu Wang ◽

Benting Wan ◽

Mengjie Han

Keyword(s):

Three Dimensional ◽

Pso Algorithm ◽

Sampling Point ◽

Compute Unified Device Architecture ◽

Point Selection ◽

Triangulated Irregular Network ◽

Device Architecture ◽

Ground Penetrating ◽

Geometry Method ◽

Difficult Issue

The identification of underground geohazards is always a difficult issue in the field of underground public safety. This study proposes an interactive visualization framework for underground geohazard recognition on urban roads, which constructs a whole recognition workflow by incorporating data collection, preprocessing, modeling, rendering and analyzing. In this framework, two proposed sampling point selection methods have been adopted to enhance the interpolated accuracy for the Kriging algorithm based on ground penetrating radar (GPR) technology. An improved Kriging algorithm was put forward, which applies a particle swarm optimization (PSO) algorithm to optimize the Kriging parameters and adopts in parallel the Compute Unified Device Architecture (CUDA) to run the PSO algorithm on the GPU side in order to raise the interpolated efficiency. Furthermore, a layer-constrained triangulated irregular network algorithm was proposed to construct the 3D geohazard bodies and the space geometry method was used to compute their volume information. The study also presents an implementation system to demonstrate the application of the framework and its related algorithms. This system makes a significant contribution to the demonstration and understanding of underground geohazard recognition in a three-dimensional environment.

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