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Wyszukujesz frazę "Ding, Z." wg kryterium: Autor


Wyświetlanie 1-3 z 3
Tytuł:
Design of large-scale streamlined head cars of high-speed trains and aerodynamic drag calculation
Autorzy:
Wu, Z.
Yang, E.
Ding, W.
Powiązania:
https://bibliotekanauki.pl/articles/224065.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
high speed train
NURBS
aerodynamic drag
streamlined head car
numerical simulation
pociąg ekspresowy
opór aerodynamiczny
symulacja numeryczna
Opis:
Aerodynamic drag plays an important role in high-speed trains, and how to reduce the aerodynamic drag is one of the most important research subjects related to modern railway systems. This paper investigates a design method for large-scale streamlined head cars of high-speed trains by adopting NURBS theory according to the outer surface characteristics of trains. This method first created the main control lines of the driver cab by inputting control point coordinates; then, auxiliary control lines were added to the main ones. Finally, the reticular region formed by the main control lines and auxiliary ones were filled. The head car was assembled with the driver cab and sightseeing car in a virtual environment. The numerical simulation of train flow field was completed through definition of geometric models, boundary conditions, and space discretization. The calculation results show that the aerodynamic drag of the high-speed train with large-scale streamlined head car decreases by approximately 49.3% within the 50-300 km/h speed range compared with that of the quasi-streamlined high-speed train. This study reveals that the high-speed train with large-scale streamlined head car could achieve the purpose of reducing running aerodynamic drag and saving energy, and aims to provide technical support for the subsequent process design and production control of high-speed train head cars.
Źródło:
Archives of Transport; 2017, 44, 4; 89-97
0866-9546
2300-8830
Pojawia się w:
Archives of Transport
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Bionic shape design of electric locomotive and aerodynamic drag reduction
Autorzy:
Wu, Z.
Huo, Y.
Ding, W.
Xie, Z.
Powiązania:
https://bibliotekanauki.pl/articles/224333.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
electric locomotive
bionic shape design
aerodynamic drag
numerical simulation
crocodile bionic electric locomotive
lokomotywa elektryczna
bioniczny design
opór aerodynamiczny
symulacja numeryczna
Opis:
Bionics has been widely used in many fields. Previous studies on the application of bionics in locomotives and vehicles mainly focused on shape optimisation of high-speed trains, but the research on bionic shape design in the electric locomotive field is rare. This study investigated a design method for streamlined electric locomotives according to the principles of bionics. The crocodiles were chosen as the bionic object because of their powerful and streamlined head shape. Firstly, geometric characteristic lines were extracted from the head of a crocodile by analysing the head features. Secondly, according to the actual size requirements of the electric locomotive head, a free-hand sketch of the bionic electric locomotive head was completed by adjusting the position and scale of the geometric characteristic lines. Finally, the non-uniform rational B-splines method was used to establish a 3D digital model of the crocodile bionic electric locomotive, and the main and auxiliary control lines were created. To verify the drag reduction effect of the crocodile bionic electric locomotive, numerical simulations of aerodynamic drag were performed for the crocodile bionic and bluff body electric locomotives at different speeds in open air by using the CFD software, ANSYS FLUENT16.0. The geometric models of crocodile bionic and bluff body electric locomotives were both marshalled with three cars, namely, locomotive + middle car + locomotive, and the size of the two geometric models was uniform. Dimensions and grids of the flow field were defined. And then, according to the principle of motion relativity, boundary conditions of flow field were defined. The results indicated that the crocodile bionic electric locomotive demonstrated a good aerodynamic performance. At the six sampling speeds in the range of 40–240 km/h, the aerodynamic drag coefficient of the crocodile bionic electric locomotive decreased by 7.7% on the average compared with that of the bluff body electric locomotive.
Źródło:
Archives of Transport; 2018, 48, 4; 99-109
0866-9546
2300-8830
Pojawia się w:
Archives of Transport
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Computational Investigation on the Structure and Performance of Novel 4,7-dinitro-furazano-[3,4-d]-pyridazine Derivatives
Autorzy:
Wang, K.
Shu, Y.
Liu, N.
Ding, X.
Wu, Z.
Lu, Y.
Powiązania:
https://bibliotekanauki.pl/articles/358090.pdf
Data publikacji:
2017
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
4,7-dinitro-furazano-[3,4-d]-pyridazine
heat of formation
density
detonation performance
bond dissociation energy
Opis:
Seven novel energetic 4,7-dinitro-furazano-[3,4-d]-pyridazine derivatives were designed, and their optimized structures and performances were studied by density functional theory (DFT) at B3LYP/6-311g(d,p) level. The detonation performances were estimated by the Kamlet-Jacobs equations. The results show that these compounds have high crystal densities (1.818-1.925 g·cm−3), detonation velocities (8.51-9.56 km·s−1) and detonation pressures (32.28-41.70 GPa). The bond dissociation energies (BDEs) of the weakest bond (N–O bond) vary from 70.889 kJ·mol−1 to 173.283 kJ·mol−1, and some of them exhibit higher BDEs than that of RDX (N–NO2 bond, 149.654 kJ·mol−1) and HMX (N–NO2 bond, 154.905 kJ·mol−1). M4 and M5 exhibit similar and higher detonation performance than RDX (8.81 km·s−1, 34.47 GPa). The detonation performance of M7 (9.56 km·s−1, 41.70 GPa) even surpasses that of HMX (9.10 km·s−1, 39.00 GPa). Otherwise, the specific impulse values of M1-M7 (266-279 s) outperform HMX (266 s) by 0-13 s, which indicates that M1-M7 may show better performance as monopropellants. It is concluded that density, heat of formation, stability, detonation performance and specific impulse of the designed compounds depend on the position and number of the N→O oxidation bonds.
Źródło:
Central European Journal of Energetic Materials; 2017, 14, 1; 26-46
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-3 z 3

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