Numerical investigation on the mixing mechanism in a cross-torus paddle mixer using the DEM-CFD method

2021 ◽  
Vol 377 ◽  
pp. 89-102
Author(s):  
Shuo Li ◽  
Shintaro Kajiwara ◽  
Mikio Sakai
2021 ◽  
Vol 9 (8) ◽  
pp. 812
Author(s):  
Lin Hong ◽  
Renjie Fang ◽  
Xiaotian Cai ◽  
Xin Wang

This paper conducts a numerical investigation on the hydrodynamic performance of a portable autonomous underwater vehicle (AUV). The portable AUV is designed to cruise and perform some tasks autonomously in the underwater world. However, its dynamic performance is strongly affected by hydrodynamic effects. Therefore, it is crucial to investigate the hydrodynamic performance of the portable AUV for its accurate dynamic modeling and control. In this work, based on the designed portable AUV, a comprehensive hydrodynamic performance investigation was conducted by adopting the computational fluid dynamics (CFD) method. Firstly, the mechanical structure of the portable AUV was briefly introduced, and the dynamic model of the AUV, including the hydrodynamic term, was established. Then, the unknown hydrodynamic coefficients in the dynamic model were estimated through the towing experiment and the plane-motion-mechanism (PMM) experiment simulation. In addition, considering that the portable AUV was affected by wave forces when cruising near the water surface, the influence of surface waves on the hydrodynamic performance of the AUV under different wave conditions and submerged depths was analyzed. Finally, the effectiveness of our method was verified by experiments on the standard models, and a physical experiment platform was built in this work to facilitate hydrodynamic performance investigations of some portable small-size AUVs.


2018 ◽  
Vol 5 (1) ◽  
pp. 22
Author(s):  
Yiyin Klistafani

A numerical investigation of asymmetric diffuser which equipped with vortex generator is presented. The investigation is aimed to know fluid flow characteristic in asymmetric diffuser which equipped with vortex generator on the up side of its diverging wall and to determine the effectiveness of using vortex generator on diffuser performance. Numerical investigation method was done by using Computational Fluid Dynamics (CFD) method with Fluent 6.3.26 software and with software of GAMBIT 2.4.6 to designed geometry and discriminated (meshing) it. The procedures performed on numerical investigation were pre-processing, solving, and post-processing stages. The results show that the flow of fluid simulated shear stress transport (SST) k-ω did not suffer a deflection toward the straight wall shortly at the time when entering the diffuser. Standard k-ε predicted the flow was deflected when entering the diffuser. Addition of vortex generator was not able to reduce the amount of adverse pressure gradient effect that occurred within the diffuser so using vortex generator was not effective to improve diffuser performance.


2016 ◽  
Vol 136 (3) ◽  
pp. 141-146 ◽  
Author(s):  
Akira Kawasaki ◽  
Kenichi Kubota ◽  
Ikkoh Funaki ◽  
Yoshihiro Okuno

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