Numerical Simulation of the Hydrodynamic Cavitation of the Impinging Streams Mixer

2014 ◽  
Vol 945-949 ◽  
pp. 951-955
Author(s):  
Fen Wang ◽  
Zhi Xia He ◽  
Yue Ma ◽  
Chang Si Li
Keyword(s):  
Numerical Simulation ◽  
Working Conditions ◽  
Vortex Flow ◽  
Technical Problem ◽  
Hydrodynamic Cavitation ◽  
Outlet Pressure ◽  
Cavitation Phenomenon ◽  
New Type ◽  
Entrance Pressure ◽  
Distribution Of Flow

The impinging streams mixer is a new type micromixer. The cavitation phenomenon occurring in the mixers with T-shaped impinging streams (TS), conical impinging streams (CIS), vortex streams(VS) were investigated, respectively. The distribution of flow field in the mixer was simulated and calculated by commercial software Fluent 6.2.1. The results showed that under the same working conditions, a more obvious hydrodynamic cavitation may occur in the CIS type impinging stream than that in the CIS type or the VS type, and the vortex flow lead to an extension of the material residence time in the mixer. The distribution of turbulent kinetic energy and gas holdup were obtained by numerical simulating hydrodynamic cavitation under different entrance pressure conditions. It is showed that when the outlet pressure keeps a constant value, hydrodynamic cavitation can be enhanced by increasing the entrance pressure. The above research can be contributed to the producing of biodiesel and the solving of the key technical problem of oil and alcohol heterogeneous mixing.

Parameter Optimization and Numerical Simulation of Dust-Collecting and Dedusting System with Air Curtain in Heading Face

2011 ◽  
Vol 317-319 ◽  
pp. 2073-2078 ◽  
Author(s):  
Jian Zhuo Zhang ◽  
Tian Zi Zhu ◽  
Meng Gao ◽  
Kang Kang Li
Keyword(s):  
Fluid Dynamics ◽  
Numerical Simulation ◽  
Dust Control ◽  
Critical Factors ◽  
Air Curtain ◽  
Wind Speeds ◽  
Outlet Pressure ◽  
New Type ◽  
Fan Speed ◽  
Optimal Efficiency

A new type of dust-collecting and dedusting system with air curtain was developed to solve the problems of the dust-prevention in mine tunnel. The speed of air-curtain fan, the structure size and pressure of dedusting duct are the critical factors, which effect dust control of the whole system. In order to achieve optimal efficiency of dust control, the simulation was conducted with FLUENT(computational fluid dynamics software) to analyse the air-curtain fan surface path lines and dust particle tracks at different wind speeds of air curtain fan, dedusting duct diameters and outlet pressures. We obtained the law of fan speed, the diameter and outlet pressure of dedusting duct, which effect the whole system on dedusting. This law would play a guiding role on the structural optimization of dust-collecting and dedusting system with air curtain.

scholarly journals Numerical and Experimental Study of Lightning Stroke to BIPV Modules

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 748
Author(s):  
Xiaoyan Bian ◽  
Yao Zhang ◽  
Qibin Zhou ◽  
Ting Cao ◽  
Bengang Wei
Keyword(s):  
Numerical Simulation ◽  
Experimental Study ◽  
Coupling Model ◽  
Maximum Temperature ◽  
Lightning Stroke ◽  
Study Results ◽  
Pv Modules ◽  
New Type ◽  
Metal Frame ◽  
Current Flows

Building Integrated Photovoltaic (BIPV) modules are a new type of photovoltaic (PV) modules that are widely used in distributed PV stations on the roof of buildings for power generation. Due to the high installation location, BIPV modules suffer from lightning hazard greatly. In order to evaluate the risk of lightning stroke and consequent damage to BIPV modules, the studies on the lightning attachment characteristics and the lightning energy withstand capability are conducted, respectively, based on numerical and experimental methods in this paper. In the study of lightning attachment characteristics, the numerical simulation results show that it is easier for the charges to concentrate on the upper edge of the BIPV metal frame. Therefore, the electric field strength at the upper edge is enhanced to emit upward leaders and attract the lightning downward leaders. The conclusion is verified through the long-gap discharge experiment in a high voltage lab. From the experimental study of multi-discharge in the lab, it is found that the lightning interception efficiency of the BIPV module is improved by 114% compared with the traditional PV modules. In the study of lightning energy withstand capability, a thermoelectric coupling model is established. With this model, the potential, current and temperature can be calculated in the multi-physical field numerical simulation. The results show that the maximum temperature of the metal frame increases by 16.07 °C when 100 kA lightning current flows through it and does not bring any damage to the PV modules. The numerical results have a good consistency with the experimental study results obtained from the 100 kA impulse current experiment in the lab.

scholarly journals Analysis of Vehicle Collision on an Assembled Anti-Collision Guardrail

Sensors ◽  
2021 ◽  
Vol 21 (15) ◽  
pp. 5152
Author(s):  
Juncheng Yao ◽  
Bo Wang ◽  
Yujie Hou ◽  
Liang Huang
Keyword(s):  
Working Conditions ◽  
Traffic Accidents ◽  
Analysis Software ◽  
Time Curve ◽  
Vehicle Collisions ◽  
Moving Vehicle ◽  
Vehicle Collision ◽  
New Type ◽  
Main Girder ◽  
Protective Performance

Traffic accidents such as vehicle collisions with bridge guardrails occur frequently. These accidents cause damage to the driver and the vehicle as well as the bridge. A new type of assembled anti-collision guardrail is proposed in this study. LS-DYNA is a nonlinear display dynamic analysis software used to evaluate the safety of a new type of assembled anti-collision guardrail. A specific, numerically analyzed model of vehicle–guardrail collision is established using LS-DYNA. The energy distribution–time curve of the vehicle collision process is obtained. After comparison with measured data from the vehicle collision test, the model of vehicle–guardrail collision is verified as being correct. Based on this, we analyze the process of a vehicle collision on the assembled anti-collision guardrail. The result shows that the assembled anti-collision guardrail proposed in this paper can better change the trajectory of a moving vehicle and can prevent the vehicle from falling off the bridge. From the car body collision results, the assembled anti-collision guardrail for bridges proposed in this paper can reduce vehicle damage and can protect the driver effectively. From the analysis of the main girder stress on the bridge, an anti-collision guardrail installed on an existing bridge will not cause damage to the main girder during a collision. In order to study the influence of the four parameters on the anti-collision effect, we carried out a comparative calculation of multiple working conditions. The results show that the new type of assembled anti-collision guardrail has good protective performance under different working conditions.

Sublimation of composite ice and its influence on performance of ice shells

2021 ◽  
Vol 36 (1) ◽  
pp. 67-77
Author(s):  
Yue Wu ◽  
Junkai Huang ◽  
Jiafeng Chen
Keyword(s):  
Numerical Simulation ◽  
Shell Structure ◽  
Composite Shell ◽  
Engineering Practice ◽  
Sublimation Rate ◽  
Long Span ◽  
Static Performance ◽  
New Type ◽  
Ice Sublimation ◽  
Composite Shell Structure

The long-span ice composite shell structure is a new type of ice and snow structure developed in recent years. The engineering practice of ice composite shell shows that sublimation is one of the important reasons for its damage and even collapse. In this paper, we firstly supplemented the existing H-K equation and obtained the revised ice sublimation equation through indoor evaporative plate experiment considering the influence of admixtures and wind speed. Afterwards, combining the simulations of solar radiation and CFD, the numerical simulation of sublimation distribution on the surface of were realized by programming in Grasshopper platform. During sublimation, the thickness of the ice composite shell decreases by 0.38 mm every 10 days and the sublimation rate on the sunny side was 1.7 times that on the shady side. Finally, the static performance and stability of the sublimated ice composite spherical shell were analyzed. After 70 days of sublimation, the thickness of the ice composite shell structure becomes thinner and uneven, which leads its sensitivity to external load increases.

Numerical Simulation Study on Cooling Characteristics of a New Type of Film Hole

2020 ◽  
Author(s):  
Chunhai Guo ◽  
Bin Wang ◽  
Zhenya Kang ◽  
Wenwu Zhang ◽  
Huilong Zheng
Keyword(s):  
Numerical Simulation ◽  
Simulation Study ◽  
New Type

Enhanced vortex stability in trapped vortex combustor

2010 ◽  
Vol 114 (1155) ◽  
pp. 333-337 ◽  
Author(s):  
S. Vengadesan ◽  
C. Sony
Keyword(s):  
Numerical Simulation ◽  
Vortex Flow ◽  
Cavity Size ◽  
Vortex Stability ◽  
Cold Flow ◽  
Air Jets ◽  
Passive Flow ◽  
Flow Through ◽  
Trapped Vortex ◽  
Driver Air

Abstract The Trapped Vortex Combustor (TVC) is a new design concept in which cavities are designed to trap a vortex flow structure established through the use of driver air jets located along the cavity walls. TVC offers many advantages when compared to conventional swirl-stabilised combustors. In the present work, numerical investigation of cold flow (non-reacting) through the two-cavity trapped vortex combustor is performed. The numerical simulation involves passive flow through the two-cavity TVC to obtain an optimum cavity size to trap stable vortices inside the second cavity and to observe the characteristics of the two cavity TVC. From the flow attributes, it is inferred that vortex stability is achieved by circulation and the vortex is trapped inside when a second afterbody is added.

Numerical Simulation Analysis for Scroll of Scroll Compressor Based on ABAQUS

2014 ◽  
Vol 488-489 ◽  
pp. 1047-1051
Author(s):  
Qing Qian Zheng ◽  
Bin Yang ◽  
Ning Chen ◽  
Hui Min Yang ◽  
Min Hu
Keyword(s):  
Numerical Simulation ◽  
Stress Distribution ◽  
Thermal Deformation ◽  
Vortex Flow ◽  
Simulation Analysis ◽  
Temperature Load ◽  
Stress And Deformation ◽  
Finite Method ◽  
Abaqus Software ◽  
Main Factor

In this paper, the finite method is applied and ABAQUS software is used, the vortex flow field is loaded as boundary condition of wraps. The stress and deformation in scroll under the action of gas pressure, temperature load and both of them is analyzed, the stress distribution and deformation of wraps in different shaft rotation angles is discussed, the stress distribution and deformation discipline of wraps are also respectively obtained. The results show that the overall stress and deformation in scroll are the largest when compression chamber is moving near the vent position and the thermal deformation is the main factor of affecting the overall deformation of scroll.

scholarly journals Numerical simulation of the accumulation of heavy particles in a circular bounded vortex flow

2016 ◽  
Vol 87 ◽  
pp. 80-89 ◽  
Author(s):  
Xiaoke Ku ◽  
Jianzhong Lin ◽  
Martin van Sint Annaland ◽  
Rob Hagmeijer
Keyword(s):  
Numerical Simulation ◽  
Vortex Flow ◽  
Heavy Particles

Study on the Integrated Design of Underground Construction Lighting and Ventilation System

2011 ◽  
Vol 374-377 ◽  
pp. 702-705
Author(s):  
Wei Feng ◽  
Hui Min Li
Keyword(s):  
Numerical Simulation ◽  
Thermal Environment ◽  
Ventilation System ◽  
Integrated Design ◽  
Structure Design ◽  
Light Environment ◽  
System Model ◽  
Underground Construction ◽  
New Type

In the underground building, Light environment and thermal environment is poorer, in order to improve the problem, this paper brings forward a new type of lighting and ventilation system model; discusses the principle and characteristics of transmission; and analyses the question that influences lighting and ventilated effect in the application. Structure design and numerical simulation is the focus of the next step.

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