scholarly journals Design of and Experiment on a Film Removal Device of an Arc-Toothed Residual Film Recovery Machine before Sowing

2021 ◽  
Vol 11 (18) ◽  
pp. 8551
Author(s):  
Shuaikang Xue ◽  
Xuegeng Chen ◽  
Jingbin Li ◽  
Xianfei Wang ◽  
Zhiyuan Zhang
Keyword(s):  
Flow Field ◽  
Inclination Angle ◽  
Optimal Parameter ◽  
Removal Rate ◽  
Internal Flow ◽  
Evaluation Index ◽  
Surface Model ◽  
Rotating Speed ◽  
Operation Process ◽  
Residual Film

In view of the serious film wrapping phenomenon and poor film removal effect of the film removal devices of residual film recovery machines, a combined “mechanical + air flow” film removal device is designed. It is mainly composed of vane-type film removal rollers and diversion shells and can complete film removal and film transportation in turn. The analysis and parameter design of the key working parts, named film stripping blades, are carried out. The condition of film removal is calculated by force analysis, and the internal flow field of the device is simulated based on the Fluent software. Taking rotating speed of the vane-type film removal roller, the inclination angle of the film stripping blade, and the diameter of the roller as test factors, and the area ratio of the vortex region to the effective region as the evaluation index, a three-factor three-level orthogonal simulation test is designed. The response surface model of each test factor is established, and the significance of each test factor on the evaluation index is analyzed. Through optimization, the optimal parameter combination suitable for the film removal flow field is obtained as follows: the rotating speed of the vane-type film removal roller is 283 r/min, the inclination angle of the film stripping blade is 25° and the diameter of the roller is 219 mm. Under the optimal combination of parameters, the device is manufactured, and the effect of the device is verified by a field test. The results show that the film removal rate of the device is 98.04%, and there is no film wrapping phenomenon in the operation process, which can meet the needs of residual film recovery before sowing.

Numerical Simulation of Counter-Current Flow Field in Double Packing Rotating Packed Bed

2013 ◽  
Vol 561 ◽  
pp. 672-676
Author(s):  
De Dong Hu ◽  
Wen Yan Shan ◽  
Guang Wei Zhu
Keyword(s):  
Flow Field ◽  
Fluid Dynamic ◽  
Internal Flow ◽  
Packed Bed ◽  
Liquid Distribution ◽  
Rotating Speed ◽  
Rotating Packed Bed ◽  
Flow Experiment ◽  
Mass Transfer Equipment ◽  
Counter Current

The rotating packed bed is a new and effective mass transfer equipment. However, because of the complexity fluid flow inside the RPB, the flow experiment are not easy to lead to the deeper understanding on the fluid dynamic in an RPB. To explore the internal flow field distribution of rotating packed bed , the internal flow field in counter-current double packing rotating packed bed was studied. At the same time, the flow field changes in different rotating speed was compared and the liquid distribution between the two layer of packing was performanced.

Research on Numerical Investigation and Test Verification of Brake Performance in a Hydrodynamic Tractor-Retarder Assembly

2010 ◽  
Vol 97-101 ◽  
pp. 3357-3361
Author(s):  
Wei Wei ◽  
Qing Dong Yan ◽  
Jing Yan Wu
Keyword(s):  
Experimental Data ◽  
Flow Field ◽  
Internal Flow ◽  
Torque Converter ◽  
Field Analysis ◽  
Rotating Speed ◽  
Spiral Vortex ◽  
Work Mechanism ◽  
Flow Field Analysis ◽  
Brake Performance

The brake performance of a hydrodynamic tractor-retarder assembly, which is the combination of torque converter and hyaulic retarder, was studied to explore its work mechanism. Spiral vortex distribution pattern of internal flow field in the assembly was discovered on the basis of reasonable boundary condition, where runaway speed of stator was determined by CFD analysis. Comparison of experimental data and flow field analysis shows that accurate brake performance of hydrodynamic tractor-retarder assembly can be calculated only by 3D flow field analysis presently and numerical simulation results is close to experimental data, and approximate linear relationship exists between runaway speed of stator and rotating speed of pump.

scholarly journals Numerical Investigation of a High-Speed Electrical Submersible Pump with Different End Clearances

Water ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 1116 ◽  
Author(s):  
Ling Zhou ◽  
Wanhong Wang ◽  
Jianwei Hang ◽  
Weidong Shi ◽  
Hao Yan ◽  
...  
Keyword(s):  
Flow Field ◽  
High Speed ◽  
Optimization Design ◽  
Structural Parameters ◽  
Engineering Application ◽  
Internal Flow ◽  
Submersible Pump ◽  
Rotating Speed ◽  
Hydraulic Design ◽  
Electrical Submersible Pump

The end clearance of the impeller is one of the most important structural parameters in the hydraulic design of a high-speed electrical submersible pump (ESP). In this paper, an ESP with a rotating speed of 6000 r/min was taken as the research object. Numerical calculations were carried out for five different end clearance conditions of 0.1 mm, 0.3 mm, 0.6 mm, 0.9 mm, and 1.2 mm, respectively, to obtain the performance and internal flow field under different situation. The simulation results were verified by the pump performance experiment. It showed that the increase of the end clearance led to a decrease of the head and efficiency of the electrical submersible pump. Through the analysis of the internal flow field, it was found that the existence of the end clearance reduced the flow rate and caused free pre-whirl. With the increase of the end clearance, the phenomenon of de-flow in the diffuser passage was aggravated, which further reduced the performance of the electrical submersible pump. Finally, the reasonable recommended value of the end clearance was given, which facilitated the optimization design and engineering application of the high-speed ESP.

THE INTERNAL FLOW FIELD ASSOCIATED WITH YAWED THREE-DIMENSIONAL RECTANGULAR CAVITIES

2000 ◽  
Vol 7 (3) ◽  
pp. 14
Author(s):  
Eric Savory ◽  
Norman Toy ◽  
Shiki Okamoto ◽  
Yoko Yamanishi
Keyword(s):  
Flow Field ◽  
Three Dimensional ◽  
Internal Flow

scholarly journals Influence of wall roughness on cavitation performance of centrifugal pump

2021 ◽  
Vol 43 (6) ◽  
Author(s):  
Weihui Xu ◽  
Xiaoke He ◽  
Xiao Hou ◽  
Zhihao Huang ◽  
Weishu Wang
Keyword(s):  
Flow Field ◽  
Centrifugal Pump ◽  
Internal Flow ◽  
Wall Roughness ◽  
Blade Surface ◽  
Centrifugal Pumps ◽  
Three Dimensional Model ◽  
Cavitation Inception ◽  
Cavitation Performance ◽  
Critical Cavitation

AbstractCavitation is a phenomenon that occurs easily during rotation of fluid machinery and can decrease the performance of a pump, thereby resulting in damage to flow passage components. To study the influence of wall roughness on the cavitation performance of a centrifugal pump, a three-dimensional model of internal flow field of a centrifugal pump was constructed and a numerical simulation of cavitation in the flow field was conducted with ANSYS CFX software based on the Reynolds normalization group k-epsilon turbulence model and Zwart cavitation model. The cavitation can be further divided into four stages: cavitation inception, cavitation development, critical cavitation, and fracture cavitation. Influencing laws of wall roughness of the blade surface on the cavitation performance of a centrifugal pump were analyzed. Research results demonstrate that in the design process of centrifugal pumps, decreasing the wall roughness appropriately during the cavitation development and critical cavitation is important to effectively improve the cavitation performance of pumps. Moreover, a number of nucleation sites on the blade surface increase with the increase in wall roughness, thereby expanding the low-pressure area of the blade. Research conclusions can provide theoretical references to improve cavitation performance and optimize the structural design of the pump.

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.

Visualization of Internal Flow Field of Propeller Fan

2017 ◽  
Author(s):  
Takaya Onishi ◽  
H. Sato ◽  
M. Hayakawa ◽  
Y. Kawata
Keyword(s):  
Flow Field ◽  
High Performance ◽  
Laser Light ◽  
Internal Flow ◽  
Light Sheet ◽  
Tip Vortex ◽  
Laser Light Sheet ◽  
Blade Surface ◽  
Similar Tendency ◽  
Flow Phenomena

Propeller fans are required not only to have high performance but also to be extremely quiet. The internal flow field of ventilation propeller fans is even more complicated because they usually have a very peculiar configuration with protruding blades upstream. Thus, many kinds of internal vortices yield which cause noise and their cause and countermeasures are needed to be clarified. The purposes of this paper are to visualize the internal flow of the propeller fan from the static and rotating frame of reference. The internal flow visualization measured from the static frame gives approximately the scale of the tip vortex. The visualization from the rotating coordinate system yields a better understanding of the flow phenomena occurring at the specific blade. The experiment is implemented by using a small camera mounted on the shaft of the fan and rotated it to capture the behavior of the vortices using a laser light sheet to irradiate the blade surface. Hence, the flow field of the specific blade could be understood to some extent. The visualized results are compared with the CFD results and these results show a similar tendency about the generation point and developing process of the tip vortex. In addition, it is found that the noise measurement result is relevant to the effect of tip vortex from the visualization result.

Research on CFD Simulation of the Cement Slurry Mixer

2012 ◽  
Vol 621 ◽  
pp. 196-199
Author(s):  
Shui Ping LI ◽  
Ya Li Yuan ◽  
Lu Gang Shi
Keyword(s):  
Flow Field ◽  
High Performance ◽  
Cfd Simulation ◽  
Structural Parameters ◽  
Internal Flow ◽  
Simulation Method ◽  
Cement Slurry ◽  
Fluid Machinery ◽  
Computational Fluid Dynamics Cfd ◽  
Machinery Design

Numerical simulation method of the internal flow field of fluid machinery has become an important technology in the study of fluid machinery design. In order to obtain a high-performance cement slurry mixer, computational fluid dynamics (CFD) techniques are used to simulate the flow field in the mixer, and the simulation results are studied. According to the analysis results, the structural parameters of the mixer are modified. The results show the mixer under the revised parameters meet the design requirements well. So CFD analysis method can shorten design period and provide valuable theoretical guidance for the design of fluid machinery.

Experiment and Optimization of High-Efficiency Mechanical Separation of Peanut Seedlings and Residual Film Based on Suspension Velocity

2021 ◽  
Vol 64 (4) ◽  
pp. 1381-1389
Author(s):  
Fengwei Gu ◽  
Meng Yang ◽  
Zhichao Hu ◽  
Yanhua Zhang ◽  
Chong Zhang ◽  
...  
Keyword(s):  
Moisture Content ◽  
Rotational Speed ◽  
Loss Rate ◽  
Removal Rate ◽  
Performance Tests ◽  
Test Results ◽  
Material Loss ◽  
Validation Test ◽  
Residual Film ◽  
Forage Utilization

HighlightsAn efficient method for separating peanut seedlings and residual film harvested from film-mulched peanut was proposed, and the mechanism was optimized.The relationships between the suspension velocity and moisture content of different shredded materials were studied.Four-factor, three-level Box-Behnken experiments were carried out and analyzed, and the optimal parameter combination was determined.A validation test was carried out to verify the rationality and accuracy of the optimized regression model.Abstract. To address the problems of lower residual film removal and higher material loss in the forage utilization of peanut seedlings wrapped in residual film, this study explored the relationships between the suspension velocity and moisture content of different shredded materials derived from peanut seedlings and conducted performance tests and parameter optimization for a machine that uses peanut seedlings as forage material. Four-factor, three-level Box-Behnken experiments were designed using the rotational speeds of the shredding shaft, upper fans, and lower fans and the frequency of the vibrating sieve as test factors, and using the residual film removal rate and material loss rate as response values. The test results indicated that the suspension velocity of the shredded materials showed a quadratic relationship with moisture content. The performance tests showed that the significance sequence of the test factors for the residual film removal rate was: rotational speed of the lower fans, rotational speed of the upper fans, rotational speed of the shredding shaft, and frequency of the vibrating sieve. The significance sequence for the material loss rate was: rotational speed of the lower fans, rotational speed of the shredding shaft, frequency of the vibrating sieve, and rotational speed of the upper fans. The parameter optimization and validation test showed that the residual film removal rate was 92.71% and the material loss rate was 8.19% when the rotational speeds of the shredding shaft, upper fans, and lower fans were 1650, 770, and 665 rpm, respectively, and the frequency of the vibrating sieve was 4 Hz. The relative errors between the validation test results and the predicted values from the regression models were less than 3%, which suggests that the regression models are reliable. This study provides a reference for the forage utilization of peanut seedlings harvested from film-mulched peanut and provides a reference for determining the optimal working parameters of forage processing machines. Keywords: Agricultural machinery, Box-Behnken experiment, Optimization, Peanut film-seedling separation, Suspension velocity.

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