An investigation of some parameter effects on the internal flow characteristics in the main nozzle

2016 ◽  
Vol 87 (1) ◽  
pp. 91-101 ◽  
Author(s):  
Yuzhen Jin ◽  
Jingyu Cui ◽  
Linhang Zhu ◽  
Peifeng Lin ◽  
Xudong Hu
Keyword(s):  
Flow Field ◽  
Textile Industry ◽  
Great Influence ◽  
Flow Characteristics ◽  
Internal Flow ◽  
Air Pressure ◽  
Weft Yarn ◽  
Internal Diameter ◽  
Air Jet ◽  
Air Jet Loom

The air-jet loom is widely used in the textile industry and the main nozzle is one of its key components. In this paper, the influence of some parameters, including the input air pressure and the structure of nozzle core and its internal diameter, on the internal flow field of the main nozzle is analyzed. Then the optimized structure of the main nozzle is proposed from the perspective of fluid dynamics. In the present simulations, the realizable [Formula: see text] model is applied to model the internal flow field of the main nozzle. The results show that the velocity in the annular throat reaches supersonic. Moreover, the pressure at the end of the nozzle core is the lowest in the main nozzle. It is also shown that the input air pressure has little effect on the axis velocity in Zone B, but on the other hand, has a great influence on the near-wall velocity field and the axis velocity in Zone C. In addition, an optimized structure of the nozzle core is proposed in this paper. It is found that with the proposed structure, the velocity boundary layer near the wall of Zone B in the accelerating tube can be well improved, and rapid diffusion of airflow in this area can be avoided. These help increase the moving speed of the weft yarn. Last but not least, we also show that decreasing of the internal diameter of the nozzle core improves the axis velocity of the weft accelerating tube. However, it brings a stronger turbulence at the same time.

Numerical simulation of the internal flow field of a new main nozzle in an air-jet loom based on Fluent

2015 ◽  
Vol 85 (15) ◽  
pp. 1590-1601 ◽  
Author(s):  
Liang Chen ◽  
Zhi-hua Feng ◽  
Teng-zhong Dong ◽  
Wei-hua Wang ◽  
Shuai Liu
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Internal Flow ◽  
Air Jet ◽  
Air Jet Loom

scholarly journals Analysis of the Influence of Different Bionic Structures on the Noise Reduction Performance of the Centrifugal Pump

Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 886
Author(s):  
Cui Dai ◽  
Chao Guo ◽  
Yiping Chen ◽  
Liang Dong ◽  
Houlin Liu
Keyword(s):  
Flow Field ◽  
Noise Reduction ◽  
Centrifugal Pump ◽  
Great Influence ◽  
Frequency Doubling ◽  
Sound Field ◽  
Internal Flow ◽  
Test System ◽  
Centrifugal Pumps ◽  
External Characteristics

The strong noise generated during the operation of the centrifugal pump harms the pump group and people. In order to decrease the noise of the centrifugal pump, a specific speed of 117.3 of the centrifugal pump is chosen as a research object. The bionic modification of centrifugal pump blades is carried out to explore the influence of different bionic structures on the noise reduction performance of centrifugal pumps. The internal flow field and internal sound field of bionic blades are studied by numerical calculation and test methods. The test is carried out on a closed pump test platform which includes external characteristics and a flow noise test system. The effects of two different bionic structures on the external characteristics, acoustic amplitude–frequency characteristics and flow field structure of a centrifugal pump, are analyzed. The results show that the pit structure has little influence on the external characteristic parameters, while the sawtooth structure has a relatively great influence. The noise reduction effect of the pit structure is aimed at the wide-band noise, while the sawtooth structure is aimed at the discrete noise of the blade-passing frequency (BPF) and its frequency doubling. The noise reduction ability of the sawtooth structure is not suitable for high-frequency bands.

scholarly journals Numerical Simulation and Experimental Study on Flow Field in a Swirl Nozzle

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Yicheng Sun ◽  
Yufan Fu ◽  
Baohui Chen ◽  
Jiaxing Lu ◽  
Wanquan Deng
Keyword(s):  
Flow Field ◽  
Velocity Distribution ◽  
Flow Characteristics ◽  
Internal Flow ◽  
Low Pressure ◽  
External Flow ◽  
Droplet Velocity ◽  
Inlet Pressure ◽  
Outlet Section ◽  
Local Pressure

In order to study the internal flow characteristics and external droplet velocity distribution characteristics of the swirl nozzle, the following methods were used: numerical simulations were used to study the internal flow characteristics of a swirl nozzle and phase Doppler particle velocimetry was used to determine the corresponding external droplet velocity distribution under medium and low pressure conditions. The distributions of pressure and water velocity inside the nozzle were obtained. Meanwhile, the velocities of droplets outside the nozzle in different sections were discussed. The results show that the flow rate in the swirl nozzle increases with the increase in inlet pressure, and the local pressure in the region decreases because of the excessive velocity at the internal outlet section of the swirl nozzle, resulting in cavitation. The experimental results show that under an external flow field, the minimum droplet velocity occurs in the axial direction; starting from the axis, the velocity first increases and then decreases along the radial direction. Swirling motion inside the nozzle and velocity variations in the external flow field occur under medium and low pressure conditions. The relationship between the inlet pressure and the distributions of water droplets’ velocities was established, which provides a reference for the research and development of the swirl nozzle.

Analysis of the characteristics of air–yarn coupling movement in the profiled reed groove of an air-jet loom

2021 ◽  
pp. 004051752110569
Author(s):  
Yuzhen Jin ◽  
Hailang Xiong ◽  
Jingyu Cui
Keyword(s):  
Numerical Results ◽  
Weft Yarn ◽  
Valuable Insight ◽  
Arbitrary Lagrangian Eulerian ◽  
Air Jet ◽  
Gap Ratio ◽  
Gas Consumption ◽  
Simulation Results ◽  
Gas Leaks ◽  
Air Jet Loom

The movement characteristics of yarn in the profiled reed groove of an air-jet loom can have a great impact on the performance of the fabric. Unstable yarn movement tends to lead to weft defects, as short wefts or weft breaks may occur, which could deteriorate the quality of the final fabric. In this paper, the characteristics of the yarn movement in a profiled reed groove are numerically studied. The arbitrary Lagrangian–Eulerian method is used to solve the two-way airflow–yarn interaction and the yarn is simulated with the ball–socket model. A fluctuation ratio is defined to characterize the unsteadiness of the yarn movement. Our simulation first investigates the effect of the gap ratio of the profiled reed groove (β) on the yarn movement then compares the movements of different yarn kinds. The simulation results indicate that a larger β not only decreases gas leaks (thus saves gas consumption), but also stabilizes the yarn movement. Our simulation results also show that the movement of the yarn of polypropylene is more stable than the other two weft-yarn materials. An experiment is also conducted to validate our numerical results, which shows a favorable agreement between them. Our numerical results of the yarn movement in the profiled reed groove can provide a valuable insight into the optimization of the weft insertion system of the air-jet loom.

Digital Analysis of Hydraulic Cone Valve Turbulence Based on Fluent 3D Solver

2013 ◽  
Vol 385-386 ◽  
pp. 93-96
Author(s):  
Hong Ji ◽  
Wei Guo Zhu ◽  
Song Chen ◽  
Jing Zhao
Keyword(s):  
Flow Field ◽  
Great Influence ◽  
Internal Flow ◽  
Energy Utilization ◽  
Valve Seat ◽  
Taper Angle ◽  
Turbulent Characteristics ◽  
Hydraulic Hammer ◽  
Drive And Control ◽  
And Control

The hydraulic cone valve is an important basic component in Fluid drive and control technology. Characteristic of cone valve inner flow filed influences directly the valves performance. Especially when fluid flow in runner is turbulent, characteristics of flow field have great influence on the valves working performance.Main work of this paper is numerical calculation and simulation of cone valve inner runner flow field inside hydraulic hammer. First make a 3D modeling for cone valve using Pro/E, by fluent this paper analyses and discusses the distribution of hydraulic cone valve internal flow field including flow velocity field, pressure field and flow, etc when the cone valve core taper angle is 30°, the gap is 0.5 mm, and inlet velocity is different, analyses position and strength of the vortex, and finds out the main reason for energy consumption.The results of the study show that by the optimal design of the cone valve seat, the density degree of the flow and the size of the vortex is reduced, the energy loss is reduced, negative pressure zone also changes, the noise is reduced and the energy utilization is improved.

Flow Characteristics of the Main Nozzle in an Air-Jet Loom

1994 ◽  
Vol 64 (2) ◽  
pp. 88-100 ◽  
Author(s):  
Minoru Ishida ◽  
Atsushi Okajima
Keyword(s):  
Flow Characteristics ◽  
Air Jet ◽  
Air Jet Loom

Statistical Model for Predicting Compressed Air Consumption on Air-Jet Looms

2014 ◽  
Vol 9 (3) ◽  
pp. 155892501400900 ◽  
Author(s):  
Abdul Jabbar ◽  
Shakeel Ahmed ◽  
Tanveer Hussain ◽  
Noman Haleem ◽  
Faheem Ahmed
Keyword(s):  
Statistical Model ◽  
Compressed Air ◽  
Dominant Factor ◽  
Weft Yarn ◽  
Prediction Ability ◽  
Textile Fabrics ◽  
Air Jet ◽  
Consumption Values ◽  
Yarn Count ◽  
Air Jet Loom

Compressed air is a major component of energy costs incurred in the weaving of textile fabrics on air-jet looms. The consumption of compressed air in air-jet weaving depends on different process variables. In this study, the effect of weft yarn count, reed count, fabric width and loom speed on the compressed air consumption of air-jet loom was determined using response surface methodology. Fabric width was found to be the most dominant factor affecting the air consumption followed by loom speed, reed count, and weft yarn count respectively. A statistical model for predicting the compressed air consumption on air-jet loom was developed. The prediction ability and accuracy of the developed model was assessed by the fitted line plot between the predicted and actual air consumption values. The prediction model may be used for optimizing the production planning, estimating the share of compressed air cost in weaving a particular fabric style, and in identifying any air wastages in the weaving shed by comparing the actual compressed air consumption with that predicted by the model which was developed under controlled conditions without any air leakages.

Analysis of Concentric Canister Wall Roughness Effect on Jet Flow Based on Fluid Dynamics

2012 ◽  
Vol 252 ◽  
pp. 3-8
Author(s):  
Yun Shan Bai ◽  
Yi Jiang ◽  
Dong Mo Zhou
Keyword(s):  
Flow Field ◽  
Influence Factor ◽  
Great Influence ◽  
Internal Flow ◽  
Rough Wall ◽  
Concentric Cylinder ◽  
Smooth Flow ◽  
Practical Engineering ◽  
Mesh Update ◽  
Main Factor

Adopting concentric canister launchers (CCL), high temperature and high pressure environment of CCL is unfavorable for the missile launch. In addition to the gap between internal canister and external canister, injecting water for cooling are the main factor of impact the canister flow field, CCL’s rough wall is also a very important influence factor. In this paper, under the two working conditions of rough wall and smooth wall, use dynamic layering manner of moving mesh update method to simulate concentric canister missile launch process. The results reveal that rough wall has a great influence for pressure of concentric canister internal flow field, but the least influence for temperature. In practical engineering applications, need smooth surface material for smooth flow field exhaust when manufacturing concentric cylinder, but the non-concentric canister manufacturing of missile cold-launch canister, retain the rough wall can increase the pressure of the missile launch, this is conducive to missile launch, and also saves manufacturing costs, reduces processing procedures.

Synthetic Flow-Field Analysis of Main and Auxiliary Nozzles in Air-Jet Looms

2011 ◽  
Vol 411 ◽  
pp. 16-20 ◽  
Author(s):  
Shuan Jun Song ◽  
Dan Feng Shen
Keyword(s):  
Flow Field ◽  
Total Pressure ◽  
Field Model ◽  
Field Analysis ◽  
Comparison Analysis ◽  
Air Jet ◽  
Before And After ◽  
Flow Field Analysis ◽  
Air Jet Loom ◽  
First Time

The synthetic flow-field model of main and auxiliary nozzle flow-field in air-jet loom is introduced. The software of computational fluid dynamics FLUENT is used for the first time to simulate synthetic flow-field, and velocity vector is analyzed. To different spray angles of auxiliary nozzle, the velocity and total pressure of central air are compared in brief. The boundary conditions are changed by User Defined Functions (UDF) and the comparison analysis is done before and after using UDF.

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