Searched for: author:"Liu, D."
(1 - 20 of 24)

Pages

document
Šavija, B. (author), Smith, G.E. (author), Liu, D (author), Schlangen, H.E.J.G. (author), Flewitt, P.E.J. (author)
Deformation and fracture of materials are usually considered in terms of brittle and ductile modes. However, there is an intermediate class between these limits that is termed quasi-brittle where there is measurable inelastic deformation prior to final graceful ‘brittle’ failure. In previous work, we presented deformation and fracture data...
journal article 2018
document
Liu, Nan (author), Liu, D. (author), Wang, Weifei (author), Hollmann, F. (author), Xu, Long (author), Ma, Yunjian (author), Yang, Bo (author), Bai, Weidong (author), Sun, Xiaotao (author), Wang, Yonghua (author)
α‐Linolenic acid‐rich diacylglycerol has been demonstrated with promising health promotion functions. This study examined the production, immobilization of lipase PCL, and its application in the synthesis of diacylglycerol by esterification of α‐linolenic acid with glycerol. The resin ECR8806 was selected as an effective support for the...
journal article 2018
document
Liu, D. (author), Tito, Nicholas B. (author), Broer, Dirk J. (author)
Coatings with a dynamic surface topography are of interest for applications in haptics, soft robotics, cell growth in biology, hydro- and air dynamics and tribology. Here we propose a design for creating oscillating surface topographies in thin liquid crystal polymer network coatings under an electric field. By applying an alternating...
journal article 2017
document
Liu, D. (author)
In recent years, superconducting synchronous generators (SCSGs) have been proposed as an alternative to permanent magnet synchronous generators (PMSGs). They are expected to reduce the top head mass and the nacelle size for such large wind turbines. In 2012, the INNWIND.EU project initiated this research to investigate SCSGs for 10-20MWdirect...
doctoral thesis 2017
document
Liu, D. (author), Polinder, H. (author), Abrahamsen, Asger B. (author), Ferreira, J.A. (author)
This paper aims at assessing the potential of partially superconducting generators for 10 MW direct-drive wind turbines by investigating their performance for a very wide range of excitation currents. Performance indicators such as shear stress and efficiency and other generator characteristics are compared for 12 different generator topologies....
journal article 2017
document
Abrahamsen, Asger Bech (author), Liu, D. (author), Magnusson, Niklas (author), Thomas, A (author), Z., Azar (author), Stehouwer, Ewoud (author), Hendriks, E (author), Penzkofer, A. (author), Atallah, K (author), Dragan, R.R. (author), .Clark, R.E. (author), Deng, F. (author), Chen, Z (author), Karwatzki, D. (author), Mertens, A. (author), Parker, M. (author), Finney, SJ (author), Polinder, H. (author)
Innovative drive trains targeted at 10-20 MW offshore turbines are investigated in the INNWIND.EU project in order to determine the impact on the Levelized Cost of Energy (LCoE) resulting when installed in the ,North sea at 50 m of water [1]. The two main technologies studied are superconducting direct drive (SCDD)[2] and the magnetic pseudo...
abstract 2017
document
Wang, X. (author), Liu, D. (author), Lahaye, D.J.P. (author), Polinder, H. (author), Ferreira, J.A. (author)
The brushless doubly-fed induction machine (DFIM) has great potential as a variable-speed generator for wind turbine applications. This special machine has a richer space-harmonic spectrum due to its special nested-loop rotor construction compared with conventional induction machines. It may result in higher iron losses, higher torque ripple and...
conference paper 2017
document
Liu, D. (author), Kenjeres, S. (author)
In the present study, we address the development and application of an efficient tool for conversion of results obtained by an integrated computational fluid dynamics (CFD) and computational reaction dynamics (CRD) approach and their visualization in the Google Earth. We focus on results typical for environmental fluid mechanics studies at a...
journal article 2017
document
Liu, D (author), Šavija, B. (author), Smith, G.E. (author), Flewitt, P.E.J. (author), Lowe, T. (author), Schlangen, H.E.J.G. (author)
In this work, porosity-property relationships of quasi-brittle materials are explored through a combined experimental and numerical approach. In the experimental part, hemihyrate gypsum plaster powder (CaSO 4 ⋅1/2H 2 O CaSO4⋅1/2H2O) and expanded spherical polystyrene beads (1.5–2.0 mm dia.) have been mixed to form a model material with...
journal article 2017
document
Song, X. (author), Liu, D. (author), Polinder, H. (author), Mijatovic, Nenad (author), Holbøll, Joachim (author), Jensen, Bogi Bech (author)
Direct drive high temperature superconducting (HTS) wind turbine generators have been proposed to tackle challenges for ever increasing wind turbine ratings. Due to smaller reactances in HTS generators, higher fault currents and larger transient torques could occur if sudden short circuits happen at generator terminals. In this paper, a finite...
journal article 2017
document
Wang, X. (author), Liu, D. (author), Lahaye, D.J.P. (author), Polinder, H. (author), Ferreira, J.A. (author)
Permanent-magnet machines with fractional slot concentrated windings are easy to manufacture. Their popularity therefore is steadily increasing. Without a proper design, however, the induced eddy-current losses in the solid rotor get rather high. The modeling and the prediction of eddy-current losses for these machines are thus very important...
conference paper 2016
document
Song, X. (author), Polinder, H. (author), Liu, D. (author), Mijatovic, Nenad (author), Holbøll, Joachim (author), Jensen, Bogi Bech (author)
Direct drive high temperature superconducting (HTS) wind turbine generators have been proposed to tackle challenges for ever increasing wind turbine ratings. Due to smaller reactances in HTS generators, higher fault currents and larger transient torques could occur if sudden short circuits happen at generator terminals. In this paper, a finite...
conference paper 2016
document
Heard, P (author), Šavija, B. (author), Liu, D (author), Smith, GE (author), Hallam, KR (author), Schlangen, H.E.J.G. (author), Flewitt, P.E.J. (author)
In quasibrittle materials the addition of specific microstructural features such as porosity can lead to departure from linear elastic behaviour prior to maximum force, followed by graceful failure. A simple but extreme example is reticulated vitreous carbon foam, with its opencell structure of brittle ligaments connected in a threedimensional...
conference paper 2016
document
Liu, D. (author), Heard, P. (author), Savija, B. (author), Smith, G. (author), Schlangen, E. (author), Flewitt, P. (author)
In the present work, the microstructure and mechanical properties of Gilsocarbon graphite have been characterized over a range of length-scales. Optical imaging, combined with 3D X-ray computed tomography and 3D high-resolution tomography based on focus ion beam milling has been adopted for microstructural characterization. A range of small...
conference paper 2015
document
Liu, D. (author), Trajanovski, S. (author), Van Mieghem, P. (author)
This paper presents a new and efficient algorithm, ILIGRA, for inverse line graph construction. Given a line graph H, ILIGRA constructs its root graph G with the time complexity being linear in the number of nodes in H. If ILIGRA does not know whether the given graph H is a line graph, it firstly assumes that H is a line graph and starts its...
journal article 2014
document
Abrahamsen, A.B. (author), Magnusson, N. (author), Liu, D. (author), Stehouwer, E. (author), Hendriks, B. (author), Polinder, H. (author)
A superconducting direct drive generator based on field windings of MgB2 superconducting tape is proposed as a solution by mounting the generator in front of the blades using a king-pin nacelle design for offshore turbines with power ratings larger than 10 MW as investigated in the INNWIND.EU project.
conference paper 2014
document
Abrahamsen, A.B. (author), Magnusson, N. (author), Jensen, B.B. (author), Liu, D. (author), Polinder, H. (author)
An MgB2 race track coil intended for demonstrating a down scaled pole of a 10 MW direct drive wind turbine generator has been designed. The coil consists of 10 double pancake coils stacked into a race track coil with a cross section of 84 mm x 80 mm. The length of the straight section is 0.5 m and the diameter of the end sections is 0.3 m....
conference paper 2014
document
Kostopoulos, D. (author), Liu, D. (author), Genani, G. (author), Polinder, H. (author)
Offshore wind is considered a vital component of the future large scale renewable generation portfolio. Intense R&D effort is occurring in both the technology and the supply chain aiming at cost reduction. The drivetrain of wind turbines is an area of continuous evolution with currently no one standard configuration in the industry. It is...
conference paper 2013
document
Liu, D. (author)
The infrastructure networks, including the Internet, telecommunication networks, electrical power grids, transportation networks (road, railway, waterway, and airway networks), gas networks and water networks, are becoming more and more complex. The complex infrastructure networks are crucial to our human society, and it has been a hot research ...
doctoral thesis 2013
document
Liu, D. (author), Trajanovski, S. (author), Van Mieghem, P. (author)
For a fixed number N of nodes, the number of links L in the line graph H(N,L) can only appear in consecutive intervals, called a band of L. We prove that some consecutive integers can never represent the number of links L in H(N,L), and they are called a bandgap of L. We give the exact expressions of bands and bandgaps of L. We propose a model...
journal article 2013
Searched for: author:"Liu, D."
(1 - 20 of 24)

Pages