ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    facet.materialart.
    Unknown
    A New Type Hi-Speed BLDC Control System Base on Indirect Current Control Strategy (2017)
    Institute of Physics (IOP)
    Details
    Publication Date: 2017-05-10
    Description: High speed BLDC has the characteristic as larger air gap smaller armature inductance, traditional PWM modulation will produce a great number of high frequency current harmonics which led problem like large torque ripple and serious motor heat. In the meantime traditional PWM modulation use the diode rectifier which cause harmonic pollution in electric power net. To solve the problem above, proposes a new motor controller topology. Using the IGBT device to replace the diode on frequency converter rectifier side, apply the power factor correction technology, reduce the pollution on the grid. Using busbar current modulation on the inverter, driving bridge-arm use 3-phase 6-state open as driving Mode, realize the control on a 10000r/min,10kw BLDC. The results of Simulation on matlab show the topological structure as proposed can effectively improve the network side power factor and reduce the motor armature winding harmonic and motor torque ripple.
    Print ISSN: 1755-1307
    Electronic ISSN: 1755-1315
    Topics: Geography , Geosciences , Physics
    Published by Institute of Physics (IOP)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 2
    facet.materialart.
    Unknown
    Influence of blade angle distribution along leading edge on cavitation performance of a centrifugal pump (2015)
    Institute of Physics (IOP)
    Details
    Publication Date: 2015-01-16
    Description: The influence of blade angle distribution along leading edge on cavitation performance of centrifugal pumps is analysed in the present paper. Three sets of blade angle distribution along leading edge for three blade inlet angles are chosen to design nine centrifugal pump impellers. The RNG k- ##IMG## [http://ej.iop.org/icons/Entities/epsilon.gif] {epsilon} turbulence model and the Zwart-Gerber-Belamri cavitation model are employed to simulate the cavitation flows in centrifugal pumps with different impellers and the same volute. The numerical results are compared with the experimental data, and the comparison proves that the numerical simulation can accurately predict the cavitation performance of centrifugal pumps. On the basis of the numerical simulations, the pump head variations with pump inlet pressure, and the flow details in centrifugal pump are revealed to demonstrate the influence of blade an...
    Print ISSN: 1757-8981
    Electronic ISSN: 1757-899X
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Published by Institute of Physics (IOP)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 3
    facet.materialart.
    Unknown
    Cavitation performance and flow characteristic in a centrifugal pump with inlet guide vanes (2015)
    Institute of Physics (IOP)
    Details
    Publication Date: 2015-01-16
    Description: The influence of prewhirl regulation by inlet guide vanes (IGVs) on cavitation performance and flow characteristic in a centrifugal pump is investigated. At the impeller inlet, the streamlines are regulated by the IGVs, and the axial velocity distribution is also influenced by the IGVs. Due to the total pressure loss on the IGVs, the cavitation performance of the centrifugal pump degrades. The cavitation area in impeller with IGVs is larger than one without IGVs. The specify values of total pressure loss between the suction pipe inlet and impeller inlet for three cavitation conditions show that the IGVs will generate additional pressure loss, which is related to the IGVs angles and cavitation conditions.
    Print ISSN: 1757-8981
    Electronic ISSN: 1757-899X
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Published by Institute of Physics (IOP)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 4
    facet.materialart.
    Unknown
    Numerical simulation of plunger valve of colliding energy dissipation in the condition of low backpressure and high pressure difference (2018)
    Institute of Physics (IOP)
    Details
    Publication Date: 2018-07-31
    Description: The plunger valve of colliding energy dissipation is one of the important parts in pipeline system. In the operation condition of low backpressure and high pressure difference, cavitation phenomenon is easy to come into being, which may result in noise and vibration and even lead to damage to valve. This article aims to decrease and even eliminate the cavitation phenomenon in plunger valve which may occur in this operation condition. Mathematical models including basic control equation, standard k-ε model, equation model of fluid, cavitation model and so on, are used to calculate flow field. Then, the physical model of plunger valve of colliding energy dissipation is built and numerical simulation study on valve’s inside flow is conducted in using software on the view of hydraulics. The physical model of plunger valve is built by using Pro/E, ICEM CFD and finally simulation is carried out by using Pumplinx software. Two calculations are performed in this study. One is calculatio...
    Print ISSN: 1755-1307
    Electronic ISSN: 1755-1315
    Topics: Geography , Geosciences , Physics
    Published by Institute of Physics (IOP)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 5
    facet.materialart.
    Unknown
    Numerical study on extracting energy efficiency by autorotation of elliptic cylinder from low velocity flow (2018)
    Institute of Physics (IOP)
    Details
    Publication Date: 2018-07-31
    Description: A new concept of power generator using autorotation of elliptic cylinder to extract energy from fluid is proposed in the present study. Numerical simulation studies Fluid-Structure Interaction of the fixed-axis autorotation of rigid elliptic cylinder using a coupled Computational Fluid Dynamics (CFD) – Rigid Body Dynamics (RBD) solver. This solver requires no solid mesh to setup FSI (Fluid Structure Interaction) simulation. Based on solving two-dimensional unsteady incompressible N-S equations and SST k - ω turbulent governing equations, the power generator of elliptic cylinder was investigated in different axis rations, eccentric distance ratios and Reynolds number conditions. Numerical results reveal that autorotation of elliptic cylinder can achieve energy extraction. With optimal parameters, the power generator can reach maximum energy extraction efficiency of 34%. The investigation results provided fundamental support for utilization of ocean current energy.
    Print ISSN: 1755-1307
    Electronic ISSN: 1755-1315
    Topics: Geography , Geosciences , Physics
    Published by Institute of Physics (IOP)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 6
    facet.materialart.
    Unknown
    Simulating-optimizing coupled method for pumping well layout at a nitrate-polluted groundwater site (2018)
    Institute of Physics (IOP)
    Details
    Publication Date: 2018-11-06
    Description: The unreasonable pumping scheme of the pump-treat technology can lead to high repair cost and poor performance in contaminated groundwater remediation. In order to improve the cost effectiveness of the technology, we took a heavily nitrate-polluted informal domestic waste landfill site in North China as an example, and optimized the pumping scheme using Visual MODFlOW software combined with genetic algorithm (GA) in MGO module. By designing the constant pumping rate scheme and phased pumping rate scheme, optimal layout of pumping wells were determined with the minimum total pumping capacity as the optimal target. The result showed that the two wells which located near the central axis and in the middle and lower reaches of the plume with a constant pumping rate of 13.2 m 3 /d and continuous pumping for 75 days was the optimal pumping solution in constant pumping rate scheme. While the pump schedule as Q 1 = 19.8 m 3 /d, Q 2 =...
    Print ISSN: 1755-1307
    Electronic ISSN: 1755-1315
    Topics: Geography , Geosciences , Physics
    Published by Institute of Physics (IOP)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 7
    facet.materialart.
    Unknown
    Numerical investigation on pressure fluctuations in centrifugal compressor with different inlet guide vanes pre-whirl angles (2013)
    Institute of Physics (IOP)
    Details
    Publication Date: 2013-12-22
    Description: The pressure fluctuations in a centrifugal compressor with different inlet guide vanes (IGV) pre-whirl angles were investigated numerically, as well as the pre-stress model and static structural of blade. The natural frequency was evaluated by pre-stress model analysis. The results show that, the aero-dynamic pressure acting on blade surface is smaller than rotation pre-stress, which wouldn't result in large deformation of blade. The natural frequencies with rotation pre-stress are slightly higher than without rotation pre-stress. The leading mechanism of pressure fluctuations for normal conditions is the rotor-stator (IGVs) interaction, while is serious flow separations for conditions that are close to surge line. A few frequency components in spectra are close to natural frequency, which possibly result in resonant vibration if amplitude is large enough, which is dangerous for compressor working, and should be avoided.
    Print ISSN: 1757-8981
    Electronic ISSN: 1757-899X
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Published by Institute of Physics (IOP)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 8
    facet.materialart.
    Unknown
    Preparation and thermal properties of carbon Nanotubes/5-Amino-1H-Tetrazole energetic composites (2017)
    Institute of Physics (IOP)
    Details
    Publication Date: 2017-07-07
    Description: Carbon nanotubes were prepared in large quantities by fluidized bed method and nitrogen-doped carbon nanotubes were prepared by chemical vapor deposition method. Carbon nanotubes/5-amino-1H-tetrazole composites were prepared by ultrasonic resonance method. The appearance characteristics and thermal properties of composites were analyzed by scanning electron microscope (SEM), transmission electron microscope (TEM), thermogravimetry (TG) and differential scanning calorimeter (DSC).
    Print ISSN: 1757-8981
    Electronic ISSN: 1757-899X
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Published by Institute of Physics (IOP)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...