Design methodology and self-turning velocity control for high-speed slim sensorless brushless direct current motors with self-lubricated bearings

2015 ◽  
Vol 84 ◽  
pp. 134-144 ◽  
Author(s):  
Hsing-Cheng Yu ◽  
Chau-Shin Jang ◽  
Wen-Yang Peng
Keyword(s):  
Direct Current ◽  
High Speed ◽  
Design Methodology ◽  
Velocity Control

Comparison of the reluctance laminated and solid rotor synchronous machine operating at high temperatures

2019 ◽  
Vol 38 (4) ◽  
pp. 1111-1119 ◽  
Author(s):  
Marcin Lefik ◽  
Krzysztof Komeza ◽  
Ewa Napieralska-Juszczak ◽  
Daniel Roger ◽  
Piotr Andrzej Napieralski
Keyword(s):  
High Speed ◽  
Design Methodology ◽  
Three Dimensional ◽  
Synchronous Machine ◽  
Point Of View ◽  
Heat Sources ◽  
Model Calculations ◽  
Content Type ◽  
Thermal Phenomenon ◽  
Practical Implications

Purpose The purpose of this paper is to present a comparison between reluctance synchronous machine-enabling work at high internal temperature (HT° machine) with laminated and solid rotor. Design/methodology/approach To obtain heat sources for the thermal model, calculations of the electromagnetic field were made using the Opera 3D program including effect of rotation and the resulting eddy current losses. To analyse the thermal phenomenon, the 3D coupled thermal-fluid (CFD) model is used. Findings The presented results show clearly that laminated construction is much better from a point of view of efficiency and temperature. However, solid construction can be interesting for high speed machines due to their mechanical robustness. Research limitations/implications The main problem, despite the use of parallel calculations, is the long calculation time. Practical implications The obtained simulation and experimental results show the possibility of building a machine operating at a much higher ambient temperature than it was previously produced for example in the vicinity of the aircraft turbines. Originality/value The paper presents the application of fully three-dimensional coupled electromagnetic and thermal analysis of new machine constructions designed for elevated temperature.

High-Performance Motion Control With Slosh: A Constrained Sliding Mode Approach

2008 ◽  
Author(s):  
Hanz Richter ◽  
Kedar B. Karnik
Keyword(s):  
High Speed ◽  
High Performance ◽  
Design Methodology ◽  
Closed Loop ◽  
Sliding Mode ◽  
Initial Conditions ◽  
Rectilinear Motion ◽  
Industrial Setting ◽  
Open Container ◽  
Nominal Performance

The problem of controlling the rectilinear motion of an open container without exceeding a prescribed liquid level and other constraints is considered using a recently-developed constrained sliding mode control design methodology based on invariant cylinders. A conventional sliding mode regulator is designed first to address nominal performance in the sliding mode. Then an robustly-invariant cylinder is constructed and used to describe the set of safe initial conditions from which the closed-loop controller can be operated without constraint violation. Simulations of a typical transfer illustrate the usefulness of the method in an industrial setting. Experimental results corresponding to a high-speed transfer validate the theory.

Comprehensive design methodology for an engine journal bearing

2000 ◽  
Vol 214 (4) ◽  
pp. 401-412 ◽  
Author(s):  
H Hirani ◽  
K Athre ◽  
S Biswas
Keyword(s):  
Film Thickness ◽  
High Speed ◽  
Design Methodology ◽  
Design Procedure ◽  
Maximum Pressure ◽  
Connecting Rod ◽  
Automotive Engine ◽  
Reciprocating Engine ◽  
High Power Output ◽  
Minimum Film Thickness

The trend towards high power output, high speed and low power loss in engines requires a better understanding of bearing behaviour. Research in this area is directed more towards different aspects involved in bearing analyses, rather than providing a comprehensive guideline on design of bearing. This effort compiles the design methodology for selection of diametral clearance and bearing length by limiting the minimum film thickness, maximum pressure and temperature. The design procedure is summarized on the basis of the existing rapid bearing analyses for evaluation of the journal trajectory, minimum film thickness and maximum pressure and simplified thermal analysis. A flow chart is provided for step-by-step bearing design. Finally, two case studies of engine bearings are described: one investigates the VEB bigend connecting-rod bearing for a large industrial reciprocating engine and the other a main crankshaft bearing for an automotive engine. The methodology translates into easy-to-use expressions and the overall procedure is outlined, using practical data to demonstrate how this can be employed effectively by users.

Study on Arc and Drop Transfer Behaviors of DCEN MAG Welding

2014 ◽  
Vol 887-888 ◽  
pp. 1290-1293
Author(s):  
Xu Ming Wang ◽  
Qing Xia Bi
Keyword(s):  
Direct Current ◽  
High Speed ◽  
Welding Process ◽  
Mag Welding ◽  
High Speed Camera ◽  
High Current ◽  
Current Electrode ◽  
The Stability

By means of the high speed camera, the arc and drop transfer behaviours of direct current electrode negative MAG welding process are researched. The influences of luminous arc ball on the stability of MAG welding process are analyzed. On this basis, the process interval of DCEN MAG welding is determined. And the influences of wire polarity on wire melting coefficient are compared. By using the shield gas 98%Ar + 2%O2, the stable drop transfer manner can be divided into two kinds: dropwise transfer with low current, and streaming transfer with high current.

scholarly journals Preparation of Nickel Nanoparticles by Direct Current Arc Discharge Method and Their Catalytic Application in Hybrid Na-Air Battery

Nanomaterials ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 684 ◽  
Author(s):  
Fengmei Su ◽  
Xuechao Qiu ◽  
Feng Liang ◽  
Manabu Tanaka ◽  
Tao Qu ◽  
...  
Keyword(s):  
Direct Current ◽  
Composite Structures ◽  
High Speed ◽  
Large Scale ◽  
Nickel Nanoparticles ◽  
Arc Discharge ◽  
Band Pass Filter ◽  
Pass Filter ◽  
Air Battery ◽  
Discharge Method

Nickel nanoparticles were prepared by the arc discharge method. Argon and argon/hydrogen mixtures were used as plasma gas; the evaporation of anode material chiefly resulted in the formation of different arc-anode attachments at different hydrogen concentrations. The concentration of hydrogen was fixed at 0, 30, and 50 vol% in argon arc, corresponding to diffuse, multiple, and constricted arc-anode attachments, respectively, which were observed by using a high-speed camera. The images of the cathode and anode jets were observed with a suitable band-pass filter. The relationship between the area change of the cathode/anode jet and the synchronous voltage/current waveform was studied. By investigating diverse arc-anode attachments, the effect of hydrogen concentration on the features of nickel nanoparticles were investigated, finding that 50 vol% H2 concentration has high productivity, fine crystallinity, and appropriate size distribution. The synthesized nickel nanoparticles were then used as catalysts in a hybrid sodium–air battery. Compared with commercial a silver nanoparticle catalyst and carbon black, nickel nanoparticles have better electrocatalytic performance. The promising electrocatalytic activity of nickel nanoparticles can be ascribed to their good crystallinity, effective activation sites, and Ni/NiO composite structures. Nickel nanoparticles prepared by the direct current (DC) arc discharge method have the potential to be applied as catalysts on a large scale.

Development and Application of a Multi-Disciplinary Multi-Regime Design Methodology of a Low-Noise Contra-Rotating Open-Rotor

2015 ◽  
Author(s):  
Michaël Leborgne ◽  
Timothée Lonfils ◽  
Ingrid Lepot
Keyword(s):  
Noise Reduction ◽  
High Speed ◽  
Design Methodology ◽  
Design Procedure ◽  
Low Noise ◽  
Design Parameters ◽  
Mechanical Constraints ◽  
Open Rotor ◽  
Mechanical Optimization ◽  
Lifting Line

This paper focuses on the development and exploitation of a multi-disciplinary, optimization-assisted, design methodology for contra-rotating open-rotors. The design procedure relies on a two-step approach. An aero-mechanical optimization is first performed to generate a geometry with good performances over several high-speed points representative of a mission. This geometry is subsequently used as the baseline of an aero-mechanical-acoustic optimization focusing on interaction noise reduction at Cutback and Sideline low-speed points. In terms of design parameters, both rotors are modified for the first phase but only the upper part of the front rotor is altered for the noise minimization. A fully-automatic high-fidelity aero-mechanical-acoustic computational chain with fluid-structure coupling is exploited in combination with evolutionary algorithms assisted by surrogate models for the constrained-optimization process. The acoustic footprint is estimated by a simplified but fast and relevant formulation combining an unsteady lifting-line and an acoustic propagation method. The best geometry of the first design gains 1.2pt in weighted efficiency while respecting all the aero-mechanical constraints. The acoustic optimization shows that noise reduction at Sideline and Cutback points is strongly antagonistic. However, significant Sideline noise reduction from 3.5 to 5.5dB depending on the harmonics is achieved while maintaining Cutback noise and without major degradation of high-speed efficiency.

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