Performance Optimization of a Newly Designed Dynamic Fluidic Sprinkler

2021 ◽  
Vol 37 (1) ◽  
pp. 33-41
Author(s):  
Xingye Zhu ◽  
Alexander Fordjour ◽  
Shouqi Yuan ◽  
Frank Agyen Dwomoh ◽  
Zakaria Issaka
Keyword(s):  
Droplet Size ◽  
Performance Optimization ◽  
Structural Parameters ◽  
Direct Analysis ◽  
Low Pressure ◽  
Nozzle Diameter ◽  
Structural Parameter ◽  
List Type ◽  
Working Pressure ◽  
Coefficient Of Uniformity

HighlightsThe results confirmed that the optimal combination of structural parameters was achieved with the factor combination of 25 mm length of the tube, 150 kPa pressure, 3 mm diameter of the tube, and 5 mm nozzle diameter.The influencing factors in decreasing order of importance were: working pressure, length of the tube, and nozzle diameter for coefficient of uniformity, and nozzle diameter working pressure and diameter of the tube for range.Droplet velocities from test 7 ranged between 0 and 6.0 m/s, while that from test 2 was slightly larger, ranging from 0 to 6.7 m/s under low-pressure conditions.ABSTRACT: To select the appropriate combination of the factors for the dynamic fluidic sprinkler, hydraulic performance tests at low pressure were conducted. The main structural parameters in this study were the length of the tube (L), pressure (H), the diameter of the tube (M), nozzle diameter (N), they are represented by factors A, B, C, and D, respectively. An orthogonal array with four factors and three levels was selected, and the direct analysis technique was used to analyze the test data. The droplets and velocities data of the sprinkler were obtained by a Thies Clima Laser Precipitation Monitor. MATLAB R20014a software was used to calculate the simulated coefficient of uniformity (CU). The results showed that the optimum values of the structural parameters were: the length of the tube (25 mm), the working pressure (150 kPa), the diameter of the tube (3 mm), and the nozzle diameter (5 mm). The factors affecting coefficient of uniformity and range, in decreasing order of importance were nozzle diameter, pressure, length of the tube, and the diameter of the tube. The highest coefficient of uniformity obtained was 91% when the length of the tube was 25 mm. Droplet sizes decreased with the increase of pressure. Droplet size ranging from 0.1 to 4 mm was obtained under test 7 with a mean droplet size of 0.38 mm. The study can give a reference to the operation for saving water in sprinkler irrigated fields. Keywords: Droplet, Dynamic fluidic sprinkler, Orthogonal test, Structural parameter, Uniformity, Velocity.

Design and Evaluation of the Key Units in a Rapeseed Direct Seeder Integrated with Plowing-Rotating Combined Tillage

2021 ◽  
Vol 37 (6) ◽  
pp. 1005-1014
Author(s):  
Guoliang Wei ◽  
Qingsong Zhang ◽  
Biao Wang ◽  
QingXi Liao
Keyword(s):  
Field Experiments ◽  
Optimal Parameter ◽  
Structural Parameters ◽  
List Type ◽  
Oil Crops ◽  
Orthogonal Experiments ◽  
Heavy Soil ◽  
Tillage Depth ◽  
Working Parameters ◽  
Orthogonal Field

HighlightsThe seeder combined the plowing and rotating tillage to overcome the heavy soil and a large amount of straws.The plow could lift and turn the soil and straw before rotary tillage.The optimal working parameters of the seeder were obtained by orthogonal field experiments.Abstract. Rapeseed, one of the most important oil crops in China, is mainly planted in the mid-lower reaches of the Yangtze River. However, limited by the special long-term rice-rapeseed rotation, rotary tillage is applied in most of the planted areas apply instead of plow tillage, leading to a shallow arable layer. On the other hand, maintaining a high-quality seedbed for rapeseed becomes a challenge because a large amount of straw remains buried in the soil. As a solution, a rapeseed direct seeder that combines plow tillage and rotary tillage was designed. The structure of the plowing unit, whose key components were a lifting-turning plow and symmetrical plow, was analyzed based on the forming principle of the plow. Furthermore, a mechanical soil throwing model of the rotary tillage blade was built to determine the structural parameters. Then, the interaction between the rotary tillage unit and the lift-turning plow was analyzed. Finally, the performance and optimal parameters were evaluated by orthogonal field experiments. The seedbed after the operations indicated that the seeder could achieve the function of turning the soil and straw first and then rotating the soil with good passability, mixing the straw and the soil, flattening the surface of the seed bed, and stabilizing the tillage depth. Orthogonal experiments showed that the optimal working parameters of the seeder were as follows: the tillage depth was 180 mm, the equipment forward speed was 2.1 km/h, and the speed of the rotary tillage blade was 250 r/min. Under the optimal parameter combination, the power consumption of the seeder, the thickness of the tillage layer, the crop residue burial efficiency, the soil breakage efficiency, and the flatness of the seed bed surface were 30.48 kW, 231 mm, 90.88%, 93.26%, and 21.15 mm, respectively. The working performance of the seeder could meet the tillage requirements of rapeseed planting. Keywords: Direct seeder, Evaluation, Plow, Plowing-rotating combined tillage, Rapeseed.

scholarly journals Wavelet multi-resolution approximation of time-varying frame structure

2018 ◽  
Vol 10 (8) ◽  
pp. 168781401879559 ◽  
Author(s):  
Min Xiang ◽  
Feng Xiong ◽  
Yuanfeng Shi ◽  
Kaoshan Dai ◽  
Zhibin Ding
Keyword(s):  
Parameter Estimation ◽  
Degrees Of Freedom ◽  
Structural Parameters ◽  
Identification Problem ◽  
Frame Structure ◽  
Structural Parameter ◽  
Time Varying ◽  
Engineering Structures ◽  
Time Frequency ◽  
Non Parametric

Engineering structures usually exhibit time-varying behavior when subjected to strong excitation or due to material deterioration. This behavior is one of the key properties affecting the structural performance. Hence, reasonable description and timely tracking of time-varying characteristics of engineering structures are necessary for their safety assessment and life-cycle management. Due to its powerful ability of approximating functions in the time–frequency domain, wavelet multi-resolution approximation has been widely applied in the field of parameter estimation. Considering that the damage levels of beams and columns are usually different, identification of time-varying structural parameters of frame structure under seismic excitation using wavelet multi-resolution approximation is studied in this article. A time-varying dynamical model including both the translational and rotational degrees of freedom is established so as to estimate the stiffness coefficients of beams and columns separately. By decomposing each time-varying structural parameter using one wavelet multi-resolution approximation, the time-varying parametric identification problem is transformed into a time-invariant non-parametric one. In solving the high number of regressors in the non-parametric regression program, the modified orthogonal forward regression algorithm is proposed for significant term selection and parameter estimation. This work is demonstrated through numerical examples which consider both gradual variation and abrupt changes in the structural parameters.

The Port Width and Position Determination for Pressure-Exchange Ejector

2012 ◽  
Vol 134 (6) ◽  
Author(s):  
Wenjing Zhao ◽  
Dapeng Hu ◽  
Peiqi Liu ◽  
Yuqiang Dai ◽  
Jiupeng Zou ◽  
...  
Keyword(s):  
High Pressure ◽  
Performance Optimization ◽  
Pressure Ratio ◽  
Low Pressure ◽  
Operating Conditions ◽  
Maximum Deviation ◽  
Dimensionless Time ◽  
Pressure Flow ◽  
Outlet Pressure ◽  
Pressure Exchange

A pressure-exchange ejector transferring energy by compression and expansion waves has the potential for higher efficiency. The width and position of each port are essential in pressure-exchange ejector design. A dimensionless time τ expressing both port widths and the positions of port ends was introduced. A prototype was designed and the experimental system was set up. Many sets of experiment with different geometrical arrangements were conducted. The results suggest that the efficiency greatly changes with the geometrical arrangements. The efficiency is about 60% at proper port widths and positions, while at improper geometrical arrangements, the efficiency is much lower and the maximum deviation may reach about 20%. The proper dimensionless port widths and positions at different operating conditions are obtained. For a fixed overall pressure ratio, the widths of the high pressure flow inlet and middle pressure flow outlet increase as the outlet pressure increases and the low pressure flow inlet width is reduced with a larger outlet pressure. The middle pressure flow outlet (MO) opening end remains constant at different outlet pressures. The positions of the high pressure flow inlet (HI) closed end and the low pressure flow inlet (LI) open end increase with the elevation of outlet pressure, however, the distance between the HI closing end and the LI opening end is constant. The port widths and positions have a significant influence on the performance of the pressure-exchange ejector. The dimensionless data obtained are very valuable for pressure-exchange ejector design and performance optimization.

On the steady posture of conical spindle distribution used in ball piston pump

2019 ◽  
Vol 234 (4) ◽  
pp. 490-499
Author(s):  
Junjie Zhou ◽  
Chongbo Jing ◽  
Jianhao Liu
Keyword(s):  
Reynolds Equation ◽  
Static Pressure ◽  
Structural Parameters ◽  
Hydraulic Pump ◽  
Working Pressure ◽  
Theoretical Support ◽  
Pressure Boundary Condition ◽  
Network Method ◽  
New Type ◽  
Gap Height

Conical spindle distribution is a new type of hydraulic pump distribution, its steady working conditions refer to a stable position of the shaft and lubrication state under constant operating condition, which directly influences the hydraulic pump efficient and reliable work. In this paper, the Reynolds equation of the tapered flow field is used to establish the lubrication model. The static pressure boundary condition of the distribution pair is obtained by the hydraulic resistance network method. The finite difference method is employed to solve the model. The static and dynamic lubricating performances including the shaft eccentricity and the distribution gap height are obtained by solving the model with a numerical method. Accordingly, the influences of structural parameters and operating parameters on the steady state are investigated, and an experimental test rig is built to validate the model. The experimental results show that the model can predict the higher working pressure which leads to higher distribution gap and eccentricity; the higher the rotational speed is, the smaller the distribution gap and the eccentricity will become, which provides theoretical support for further guidance of the distribution design.

Numerical Simulation and Experimental Study on Tar Decomposition of Low-Pressure Ejection Type Burner

2015 ◽  
Vol 1092-1093 ◽  
pp. 200-206
Author(s):  
De Fan Qing ◽  
Mao Kui Zhu ◽  
Yang Cheng Luo ◽  
Ya Long Zhang ◽  
Ai Rui Chen ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Flow Rate ◽  
Gas Flow ◽  
Low Pressure ◽  
Orthogonal Test ◽  
Nozzle Diameter ◽  
Design Parameters ◽  
Minor Effect ◽  
Gas Flow Rate ◽  
Tar Cracking

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.

Effect of Combination Factors of Operating Pressure, Nozzle Diameter and Riser Height on Sprinkler Irrigation Uniformity

2014 ◽  
Vol 695 ◽  
pp. 380-383 ◽  
Author(s):  
Manal Osman ◽  
Suhaimi B. Hassan ◽  
Khamaruzaman B. Wan Yusof
Keyword(s):  
Irrigation System ◽  
Sprinkler Irrigation ◽  
Nozzle Diameter ◽  
Operating Pressure ◽  
Irrigation Uniformity ◽  
Distribution Uniformity ◽  
Coefficient Of Uniformity ◽  
Riser Height ◽  
Design Factors ◽  
Pressure Nozzle

The irrigation uniformity of sprinkler irrigation system depends on many design factors such as nozzle type, nozzle diameter, operating pressure and riser height. An experimental study was performed to investigate the effect of combination factors of operating pressure, nozzle diameter and riser height on sprinkler irrigation uniformity. Different operating pressures, nozzle diameters and riser heights have been used. The irrigation uniformity coefficients such as coefficient of uniformity (CU) and distribution uniformity of low quarter (DUlq) have been studied. This study concluded that, the irrigation uniformity of sprinkler irrigation system was more affected by the combination of operating pressure, nozzle diameter and riser height.

Studies of molecular structure parameters of 20-piperidin-2-yl-5α-pregnan-3β,20-diol and its N-methyl derivative: two inhibitors of Δ24(25) sterol methyl transferase and Δ24(24′) sterol methyl reductase of Trypanosoma cruzi

2001 ◽  
Vol 57 (5) ◽  
pp. 714-721 ◽  
Author(s):  
Reinaldo Atencio ◽  
Gonzalo Visbal ◽  
Sara Pekerar ◽  
Jham Papale ◽  
Julio A. Urbina
Keyword(s):  
Trypanosoma Cruzi ◽  
Structural Parameters ◽  
Spectroscopic Characterization ◽  
Structural Parameter ◽  
Torsion Angles ◽  
Methyl Transferase ◽  
X Ray ◽  
The Family ◽  
Fused Ring ◽  
The Mean

Molecular structural parameters of two potential drugs against Trypanosoma cruzi epimastigotes, 20-piperidin-2-yl-5α-pregnan-3β,20-diol (1) and 20-N-methylpiperidin-2-yl-5α-pregnan-3β, 20-diol (2) were studied using a combination of a stereoselective synthetic route, spectroscopic characterization and single-crystal X-ray analysis. Both compounds were synthesized with an R configuration at C20. This chirality is a consequence of the stereoselectivity observed during the formation of the intermediate 20-pyridin-2-yl-5α-pregnan-3β,20R-diol (4). NMR data indicated that the six-membered aza ring of (2) is conformationally more restrained, in CDCl3 solution, than (1). X-ray studies showed that maximum deviations among structural molecular parameters of (1) and (2) correspond to torsion angles along the C20—C22 bonds, leading to a different relative orientation of the N atom; a critical structural parameter for the binding properties of aza-sterols to Δ24(25) sterol methyl transferase. Cremer–Pople parameters of the five-membered rings of (1) and (2) lie in the observed range for a family of tetracyclic fused ring systems retrieved from the CSD. The φ2 parameter of (1) lies just on the mean of the family, while φ2 of (2) deviates significantly towards the lower limit.

Derivatives and Parameter Designs of Arbitrary Cross-Section Inhomogenous Beams’ Modes

2013 ◽  
Author(s):  
J. W. Xing ◽  
G. T. Zheng
Keyword(s):  
Cantilever Beam ◽  
Cross Section ◽  
Analytical Solutions ◽  
Structural Parameters ◽  
Arbitrary Cross Section ◽  
Mode Shapes ◽  
Design Parameters ◽  
Structural Parameter ◽  
Highly Sensitive ◽  
Sensitivity Analysis Method

As highly sensitive to structural parameter variations, it is necessary to study relations between derivatives of displacement modes and structural design parameters. This paper proposes an integral technique for obtaining the analytical solutions of slope and curvature modes of arbitrary cross-section inhomogeneous cantilever beam. The method is validated by comparing the computation results of modal frequencies and shapes with both numerical and analytical solutions. Furthermore, based on the presented method, we have established explicit expressions for the structural parameters sensitivity of the slope/curvature mode shapes. An example of parameter design is also presented for a cantilever beam with the proposed sensitivity analysis method.

scholarly journals Astrometric Plate Reduction with Orthogonal Functions and Milliarcseconds Accuracy in Deep Proper Motion Surveys

1995 ◽  
Vol 166 ◽  
pp. 368-368
Author(s):  
Devendra Ojha ◽  
Olivier Bienaymé
Keyword(s):  
Galactic Plane ◽  
Structural Parameters ◽  
Thin Disk ◽  
Scale Height ◽  
Thick Disk ◽  
Sample Survey ◽  
Time Base ◽  
List Type ◽  
Proper Motions ◽  
Velocity Dispersions

We have been doing a sample survey in UBV photometry and proper motions as part of an investigation of galactic structure and evolution. The 3 fields in the direction of galactic anticentre (l = 167°, b = 47°), centre (l = 3°, b = 47°) and antirotation (l = 278°, b = 47°) have been surveyed. The high astrometric quality of the MAMA machine (CAI, Paris) gives access to micronic accuracy (leading to < 2 mas per year) on proper motions with a 35 years time base. The kinematical distribution of F and G–type stars have been probed to distances up to 2.5 kpc above the galactic plane. We have derived the constrain on the structural parameters of the thin and thick disk components of the Galaxy (Ojha et al. 1994abc): • The scale lengths of the thin and thick disks are found to be 2.6±0.1 and 3.3±0.5 kpc, respectively. The density laws for stars with 3.5≤MV≤5 as a function of distance above the plane follow a single exponential with scale height of ∼ 260 pc (thin disk) and a second exponential with scale height of ∼ 800 pc (thick disk) with a local normalization of 5–6% of the disk.• The thin disk population was found with (〈 U+W〉, 〈V〉) = (1±4, −14±2) km/s and velocity dispersions (σU+W, σV) = (35±2, 30±1) km/s. The thick disk population was found to have a rotational velocity of Vrot = 177 km/s and velocity dispersions (σU, σV, σW) = (67,51,42) km/s. No dependence with r and z distances was found in the asymmetric drift measurements of the thick disk population.

Blood Pressure Parameters as Determinants of Small Artery Structure in Human Essential Hypertension

1997 ◽  
Vol 92 (6) ◽  
pp. 551-557 ◽  
Author(s):  
Anne Cooper ◽  
Anthony M. Heagerty
Keyword(s):  
Blood Pressure ◽  
Essential Hypertension ◽  
Pulse Pressure ◽  
Structural Parameters ◽  
Structural Parameter ◽  
Pressure Measurements ◽  
Significant Determinant ◽  
Small Artery ◽  
Small Arteries ◽  
Blood Pressures

1. Adaptive changes in small arteries may be more closely correlated with pulse pressure than with systolic, diastolic or mean blood pressures in human essential hypertension. 2. An analysis was performed on the structure of small arteries, age and blood pressure measurements obtained from 56 patients with untreated essential hypertension and 56 matched normotensive volunteers to examine the association between age, blood pressure and small artery structural parameters. 3. Essential hypertension was associated with an increase in media thickness and a decrease in lumen diameter, resulting in an increase in media/lumen ratio. 4. There was a significant correlation between age and media/lumen ratio in normotensive volunteers but not in patients with essential hypertension. 5. There was no correlation between any blood pressure and structural parameter in normotensive volunteers. 6. Both diastolic and mean blood pressures in essential hypertension correlated with media/lumen ratio (P < 0.01); systolic blood pressure correlated less well (P < 0.02). However, pulse pressure did not correlate with media/lumen ratio, suggesting that it is not a significant determinant of small artery structure in untreated essential hypertension.

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