scholarly journals Numerical simulation of the air flow field in the foreign fiber separator

2016 ◽  
Vol 20 (3) ◽  
pp. 953-956 ◽  
Author(s):  
Ting Chen ◽  
Kang Yang ◽  
Li-Li Wu

The air flow field of a foreign fiber separator is simulated numerically. Effects of design parameters such as the nozzle diameter and entrance width of the noil box on the air velocity along nozzle axis, turbulence intensity, and jet deflection distance are studied. Larger nozzle diameters and larger entrance widths of the noil box are advantageous to the elimination of foreign fibers. The results provide a theoretical basis for the design of foreign fiber separators.

e-Polymers ◽  
2016 ◽  
Vol 16 (4) ◽  
pp. 337-342 ◽  
Author(s):  
Xin Sanfa ◽  
Wang Xinhou

AbstractThe effect of the angle of dual slots on an air flow field in melt blowing was researched via numerical simulation. Through establishing the geometric model of air flow field in melt blowing with dual slots, meshing, designating the boundary conditions and their parameters and numerical simulation, the result illustrates the influence of the angle of dual slots on the variations of air velocity, pressure and temperature distributions. Higher peak values of air velocity, pressure and temperature are obtained with larger angles of dual slots near the die, while only a few differences of these parameters are detected away from the die. Our results demonstrate the angle of 70° is the appropriate one that can produce the finest fibers.


2015 ◽  
Vol 713-715 ◽  
pp. 47-50
Author(s):  
Hao Li ◽  
Zhi Jun Zou ◽  
Fei Wang

Air velocity in oven box is an important factor. The value of air velocity will affect the result of drying. This paper use the method of numerical simulation to research the effect of orifice plate on flow field and thermal environment in oven box. The results show the change rate of thermal environment & air flow field in oven box is depend on supply air volume, and the use of orifice plate will affect the flow field obviously.


2011 ◽  
Vol 328-330 ◽  
pp. 1755-1758
Author(s):  
Han Xiao Liu ◽  
Zhong Liu ◽  
Huai Liang Li ◽  
Xin Xin Feng ◽  
Zhen Zhong Xing

In this paper, the continuity equation, momentum equation and the k-ε turbulence equation were introduced to simulate the flow field of the multiple vortex bodies in different spacing cases. Found that each vortex body had good effect in producing vortex, and the greater flow field spacing, the smaller the highest velocity; the turbulence intensity is increasing gradually from the former vortex body to the next one, and there may be a best spacing between the vortex bodies which makes the best turbulent intensity. All of these theories provide a train of thought for the turbulent coalescence mechanism.


2015 ◽  
Vol 1092-1093 ◽  
pp. 200-206
Author(s):  
De Fan Qing ◽  
Mao Kui Zhu ◽  
Yang Cheng Luo ◽  
Ya Long Zhang ◽  
Ai Rui Chen ◽  
...  

The tar decomposition of low-pressure ejection type burner was researched. The burner used software to simulate and analyse impact of the nozzle diameter d, the gas flow rate V and the distance of the nozzle to the wall L on tar cracking. The orthogonal test were used for design parameters d, V and L, the optimization values of these three parameters were carried out, and experimental method was used for test the numerical simulation results. Numerical simulation and experimental results showed that the greatest impact on tar cracking is the nozzle diameter d, the minor effect is the distance of the nozzle to the wall L and the weakest effect is the gas flow rate V, and when the nozzle diameter d=4 mm, the distance L=18 mm and the gas flow rate V=0.10 m3/h, the tar cracking is the most efficiency.


2013 ◽  
Vol 749 ◽  
pp. 554-560
Author(s):  
Jing Xie ◽  
Chen Miao ◽  
Zhi Li Gao ◽  
Jian Bing Shi ◽  
Tai Wang

Air curtains are commonly used to cut off air flow between the cold store and hot environment, and reduce heat and mass transfer in order to maintain the low temperature in the cold store. CFD can be used to predict operation rule of air curtain used in the cold store intuitively and modelling is the most important part of numerical simulation of air curtain used in the cold store. In this study, different numerical models including standardmodel (with and without boussinesq approximation) and RSM (with and without boussinesq approximation) were used to simulate the temperature field and air flow field in the cold store and operation rule of air curtain used in the cold store after air curtain opened for 60s. Meanwhile, the actual operation of air curtain used in the cold store was tested and the simulation values were compared with the experimental values. The results showed that the velocity of the central mainstream decayed slowly, but the velocity of both sides of air curtain decayed fast. The optimal model used to predict the temperature field and air flow field in the cold store and operation rule of air curtain used in the cold store was standardmodel with boussinesq approximation, the relative error was within 20%. The optimal model can be used to predict the temperature field and air flow field in the cold store during different times in the future research.


2016 ◽  
Vol 88 (3) ◽  
pp. 237-253 ◽  
Author(s):  
Nicholus Tayari Akankwasa ◽  
Huiting Lin ◽  
Yuze Zhang ◽  
Jun Wang

In order to regulate turbulence strength and determine airflow characteristics in a new dual-feed rotor spinning unit, the internal flow field is investigated. A computational fluid dynamics technique is employed to numerically study the three-dimensional model of the internal airflow in the new design. The effects of air velocity variation on turbulence strength, negative pressure, Re, and wall pressure distribution are investigated based on simulation data and previous studies. The results show that the turbulence strength and Re increased with increase in inlet air velocity. Pressure profiles inside the rotor varied significantly with positive pressure observed at the channel exits. Minimal inlet velocity maintains the flow field in the rotor interior below 100 m/s, which gives the ideal turbulence required to minimize yarn quality deterioration. The dual-feed rotor spinning unit showed more orderly streamline patterns with fewer vortices compared to the conventional one. The numerical simulation can provide insights on airflow studies and some guidelines for future prototyping and experiments to further improve the new design.


2021 ◽  
Vol 25 (6 Part A) ◽  
pp. 4091-4098
Author(s):  
Shiyang Liu ◽  
Kun Xiang ◽  
Feng Gao ◽  
Xuefu Zhang ◽  
Yun Li ◽  
...  

The crystal plugging of tunnel drainage pipe seriously affects the safe and normal use of the tunnel. In order to obtain the mechanism of flocking drainage pipe anti crystal plugging based on the characteristics of flow field distribution, numerical simulation was used to optimize the parameters of flocking drainage pipe. The results show that: with the existence of fluff, the velocity in the lower part of the drainage pipe decreases by about 50%, and the velocity in the upper part increases by about 25~50%. With the increase of the length of fluff, the velocity funnel between fluffs gradually increases, the velocity distribution at the bottom of the funnel is basically unchanged, and the velocity in the upper part gradually increases. The velocity in the upper part of the flocked drainage pipe fluctuates above the fluff to a certain extent. The flow velocity in the lower part of the drainage pipe forms a flow velocity ladder in the longitudinal direction of the villus, and the width of the ladder is about 2/3 of the longitudinal spacing of the villus. The optimized parameters of 3-D flow field of flocked drainage pipe are helpful to the further improvement of indoor test, and provide theoretical basis for the mechanism of preventing crystal blockage of flocked drainage pipe.


2021 ◽  
Vol 12 (1) ◽  
pp. 539-557
Author(s):  
Lihong Jin ◽  
Junpeng Shao ◽  
Xigui Wang ◽  
Yongmei Wang ◽  
Baixue Fu

Abstract. Previous studies have attempted to identify weak links in the dynamic characteristics of the planetary gear reducer (PGR) exterior body structure (EBS). Through numerical simulation, these studies analyzed the mode and natural frequencies and the vibration types of each order of the EBS. However, these scholars have never focused on the main factors affecting the dynamic characteristics of the EBS of this subject. This study in the topic has analyzed the vibroacoustic characteristics of an EBS and optimized its design using numerical simulation. Herein, the contribution of the vibration transfer path from the excitation points on the exterior body to the machine foot is emphatically revealed, and the influences of the main structural parameters on the transfer characteristics are discussed. An optimal EBS for a PGR with lower acoustic vibrations is designed in detail, and a composite EBS with damping vibration attenuation and acoustic absorption is proposed. The radiation acoustic characteristics without acoustic protection and damping materials are analyzed. These research results are implemented in order to realize the dynamic characteristics, transmission, and radiation acoustic characteristics as objects of optimization, and the structural design parameters of the PGR exterior body are deeply optimized using dynamic modification and sensitivity analysis. This topic focuses on the vibroacoustic coupling of EBS in stationary fluid and average flow field. Based on the analysis method of theoretical modeling and numerical calculation, the EBS dynamic response and vibroacoustic characteristics under the action of frontal excitation external acoustic flow field are studied, which will be beneficial to explore the comprehensive optimization design of PGR dynamic and vibroacoustic properties.


2018 ◽  
Vol 22 (4) ◽  
pp. 1589-1593 ◽  
Author(s):  
Chen-Yang Xu ◽  
Li-Li Wu ◽  
Ting Chen

The air-flow field of the circumferentially arranged nozzle group is modeled and simulated. The air velocity distribution is measured using a hot wire anemometer. The results show that the simulated velocities coincide with the measured ones, confirming the effectiveness of the model. Larger rotating speeds can yield larger air velocities, indicating that introducing auxiliary air is favorable to the polymer drawing in the centrifugal spinning.


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