Shadowing Effect Analyzing for Propeller-Ice Milling Condition With Peridynamics

Author(s):  
Wei Peng Xiong ◽  
Wang Chao

During the research of propeller-ice contact process, we found that shadowing effect has great influence on the ice loads of propeller blade. Therefore, more study in the shadowing effect would be helpful to solve the complicated propeller-ice contact problem. A numerical simulation model is established based on the coupling of peridynamics and panel method in this paper, and ice force for the whole blade and for blade back and blade face separately are obtained through the calculation of the simulation model. The influence law to ice loads of shadowing effect would be revealed clearly by comparing the loads of blade face with the loads of blade back .On this basis, more research is carried out on the mechanism of shadowing effect. In addition, a new calculation formula for shadowing coefficient is put forward in this paper. The results show that the influence of shadowing effect on propeller loads is well predicted by the calculation result of shadowing coefficient formula.

2014 ◽  
Vol 134 (7) ◽  
pp. 604-613 ◽  
Author(s):  
Toshiya Ohtaka ◽  
Tomo Tadokoro ◽  
Masashi Kotari ◽  
Tadashi Amakawa

1997 ◽  
Vol 36 (8-9) ◽  
pp. 397-402
Author(s):  
Yasuhiko Wada ◽  
Hiroyuki Miura ◽  
Rituo Tada ◽  
Yasuo Kodaka

We examined the possibility of improved runoff control in a porous asphalt pavement by installing beneath it an infiltration pipe with a numerical simulation model that can simulate rainfall infiltration and runoff at the porous asphalt pavement. From the results of simulations about runoff and infiltration at the porous asphalt pavement, it became clear that putting a pipe under the porous asphalt pavement had considerable effect, especially during the latter part of the rainfall.


2020 ◽  
pp. 014459872098361
Author(s):  
Zhongbao Wu ◽  
Qingjun Du ◽  
Bei Wei ◽  
Jian Hou

Foam flooding is an effective method for enhancing oil recovery in high water-cut reservoirs and unconventional reservoirs. It is a dynamic process that includes foam generation and coalescence when foam flows through porous media. In this study, a foam flooding simulation model was established based on the population balance model. The stabilizing effect of the polymer and the coalescence characteristics when foam encounters oil were considered. The numerical simulation model was fitted and verified through a one-dimensional displacement experiment. The pressure difference across the sand pack in single foam flooding and polymer-enhanced foam flooding both agree well with the simulation results. Based on the numerical simulation, the foam distribution characteristics in different cases were studied. The results show that there are three zones during foam flooding: the foam growth zone, stable zone, and decay zone. These characteristics are mainly influenced by the adsorption of surfactant, the gas–liquid ratio, the injection rate, and the injection scheme. The oil recovery of polymer-enhanced foam flooding is estimated to be 5.85% more than that of single foam flooding. Moreover, the growth zone and decay zone in three dimensions are considerably wider than in the one-dimensional model. In addition, the slug volume influences the oil recovery the most in the foam enhanced foam flooding, followed by the oil viscosity and gas-liquid ratio. The established model can describe the dynamic change process of foam, and can thus track the foam distribution underground and aid in optimization of the injection strategies during foam flooding.


2005 ◽  
Vol 45 (4) ◽  
pp. 500-505 ◽  
Author(s):  
Junya KANO ◽  
Eiki KASAI ◽  
Fumio SAITO ◽  
Takazo KAWAGUCHI

Author(s):  
Hairui Wang ◽  
Chunfang Guo ◽  
Yujie Li ◽  
Yahua Liu ◽  
Minjie Wang ◽  
...  

With the advantage of high adaptability, Miura-origami structure with curvature shows various engineering applications such as a sandwich between two stiff facings with curvature requirements and structural support to form a circular tube. In this research, a forming method of polymer circular tube with single-curved surface origami expressed by five parameters was established and its corresponding theory was solved considering forming rationality in actual manufacturing. The components of circular tube were fabricated by the vacuum forming process and then spliced together. We conducted numerical simulation to analyze the structural performance of the tube with five parameters and shown that these parameters have a great influence on energy absorbed performance. Finally, a male mold of a part with Arc Miura-origami structure was designed and fabricated. The parts with Arc Miura-origami were manufactured using vacuum forming process and then spliced and bonded together into a two-layer tube. This research may provide a method to design and fabricate Miura-origami structure with high efficiency and quality.


Author(s):  
Qiao Luo ◽  
Xiaobing Zhang

Purpose – In engineering applications, gas-solid two-phase reaction flow with multi-moving boundaries is a common phenomenon. The launch process of multiple projectiles is a typical example. The flow of adjacent powder chambers is coupled by projectile’s motion. The purpose of this paper is to study this flow by numerical simulation. Design/methodology/approach – A one-dimensional two-phase reaction flow model and MacCormack difference scheme are implemented in a computational code, and the code is used to simulate the launch process of a system of multiple projectiles. For different launching rates and loading conditions, the simulated results of the launch process of three projectiles are obtained and discussed. Findings – At low launching rates, projectiles fired earlier in the series have little effect on the launch processes of projectiles fired later. However, at higher launching rates, the projectiles fired first have a great influence on the launch processes of projectiles fired later. As the launching rate increases, the maximum breech pressure for the later projectiles increases. Although the muzzle velocities increase initially, they reach a maximum at some launching rate, and then decrease rapidly. The muzzle velocities and maximum breech pressures of the three projectiles have an approximate linear relationship with the charge weight, propellant web size and chamber volume. Originality/value – This paper presents a prediction tool to understand the physical phenomenon of the gas-solid two-phase reaction flow with multi-moving boundaries, and can be used as a research tool for future interior ballistics studies of launch system of multiple projectiles.


2014 ◽  
Vol 501-504 ◽  
pp. 248-253
Author(s):  
Liu Yong Cheng ◽  
Shan Xiong Chen ◽  
Xi Chang Xu ◽  
Xiao Jie Chu ◽  
Tong Bing Lei

The regular pattern of the lateral friction transmission is one of the most critical influences on the ultimate uplift bearing capacity. The pile foundation in the incline under the pulling force has a wide variety of characteristics which is different with the normal pile. Numerical simulation is done by the use of FLAC3D in this paper. The regular pattern of the lateral friction transmission of the pile in the incline under the pulling force is studied. And the influence factors on the lateral friction transmission such as the slope gradient, the length and location of piles are discussed. The results show that the incline has a great influence on the lateral friction transmission. The lateral friction which is away from the incline-side is about 30% to 50% bigger than the incline-side. The slope gradient and the location of piles all have a great influence on the lateral friction transmission.


2011 ◽  
Vol 339 ◽  
pp. 624-629
Author(s):  
Lian Cheng Ren ◽  
Zheng Liang ◽  
Jiang Meng ◽  
Lin Yang ◽  
Jia Lin Tian

On the base of numerical simulation and theoretical analysis, the flow field of a conventional single-tangential-inlet Hydrocyclone and a newly put forward axial-symmetry double-tangential-inlet hydrocyclone were contrasted. The study shows that the inlet structure of the Hydrocylone has a great influence on the radial velocity of the flow field in the hydrocyclone and that the radial velocity in the hydrocyclone with single-tangential-inlet is not symmetry about the axis of the hydrocyclone; and on the other hand the radial velocity in the hydrocyclone with axial-symmetry double-tangential-inlet is symmetry about the axis of the hydrocyclone. The magnitude of the radial velocity of the flow in the hydrocyclone with single-tangential-inlet is greater than that in the hydrocyclone with axial-symmetry double-tangential-inlet hydrocyclone, which means the hydrocyclone with axial-symmetry double-tangential-inlet has greater capability than the rival one with single-tangential inlet. The symmetry about the axis of the hydrocyclone of the radial velocity means the radial velocities in the place where the radio is the same are constant, which means the hydrocyclone has a great separation efficiency. The conclusion is that changing the conventional hydrocyclone into the one with axial-symmetry double-tangential-inlet structure can offer greater separation capability and efficiency.


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