scholarly journals Assessing sprinkler systems performance with a novel experimental benchmark

2021 ◽  
Vol 52 (3) ◽  
Author(s):  
Andrea Petroselli ◽  
Dario Romerio ◽  
Piero Santelli ◽  
Roberto Mariotti ◽  
Silvano Di Giacinti ◽  
...  
Keyword(s):  
Optimal Design ◽  
Working Conditions ◽  
Water Application ◽  
Sprinkler Systems ◽  
Application Depth ◽  
Depth Curves

Sprinkler systems are one of the most popular methods of irrigation worldwide. One of their key parameters is the so-called level of uniformity, i.e. every portion of the soil should be irrigated with the same amount of water. Assessing the level of uniformity is crucial for optimal design of sprinkler systems. In this manuscript, a novel experimental benchmark is presented in order to test irrigation sprinklers, assess their performance, and define their acceptable working conditions. Different sprinklers have been tested, their water application depth curves have been determined, and their performance has been evaluated using a combination of metrics. Results show that the majority of sprinklers are characterized by very good performance in terms of operating pressures in the range 2.0-3.0 bar and tend to decrease their efficiency for operating pressures outside of that range.

scholarly journals Optimal Design of a 3-DOF Cable-Driven Upper Arm Exoskeleton

2014 ◽  
Vol 6 ◽  
pp. 157096 ◽  
Author(s):  
Zhu-Feng Shao ◽  
Xiaoqiang Tang ◽  
Wangmin Yi
Keyword(s):  
Optimal Design ◽  
Working Conditions ◽  
Parallel Manipulator ◽  
Degree Of Freedom ◽  
Design Parameters ◽  
Rehabilitation Robot ◽  
Challenging Problem ◽  
System Safety ◽  
Upper Arm ◽  
Global Force

With outstanding advantages, such as large workspace, flexibility, and lightweight and low inertia, cable-driven parallel manipulator shows great potential for application as the exoskeleton rehabilitation robot. However, the optimal design is still a challenging problem to be solved. In this paper, the optimal design of a 3-DOF (3-degree-of-freedom) cable-driven upper arm exoskeleton is accomplished considering the force exerted on the arm. After analysis of the working conditions, two promising configurations of the cable-driven upper arm exoskeleton are put forward and design parameters are simplified. Then, candidate ranges of two angle parameters are determined with the proposed main workspace requirement. Further, global force indices are defined to evaluate the force applied to the arm by the exoskeleton, in order to enhance the system safety and comfort. Finally, the optimal design of each configuration is obtained with proposed force indices. In addition, atlases and charts given in this paper well illustrate trends of workspace and force with different values of design parameters.

DEFORM-Based Analysis and Discussion of Early Failure in Warm Extrusion Dies

2014 ◽  
Vol 1028 ◽  
pp. 68-75
Author(s):  
An Min Zhang
Keyword(s):  
Working Conditions ◽  
Test Point ◽  
Wear Depth ◽  
Early Failure ◽  
Extrusion Dies ◽  
Extrusion Die ◽  
3D Software ◽  
Deform 3D ◽  
Warm Extrusion ◽  
Depth Curves

In this study, the true working conditions of a warm extrusion die was simulated using DEFORM-3D software; images of the die’s temperature, stress, and wear distributions were obtained, the amount of wear of the die cavity were calculated, and the wear depth curves were drawn for each test point on the basis of this simulation. A production analysis along with the simulation revealed the main forms of early failure for the warm extrusion mold to be cracking failure, collapsing failure, and wear failure. Through data analysis, the areas of the die that cracked easily or showed heavy wear were identified. The steps required to prevent early failure are proposed in this article.

Optimal Design of Mainshaft Bearing for Wind Turbine

2010 ◽  
Vol 171-172 ◽  
pp. 252-255 ◽  
Author(s):  
Qing Zhou ◽  
Xin Tao Xia ◽  
Ya Ping Zhang
Keyword(s):  
Mathematical Model ◽  
Optimal Design ◽  
Constrained Optimization ◽  
Wind Turbine ◽  
Working Conditions ◽  
Wind Turbines ◽  
Dynamic Load ◽  
Optimization Method ◽  
Matlab Toolbox ◽  
Bearing Life

Working conditions, characteristics, and development about the mainshaft bearing for wind turbines are investigated and mathematical model based on the rated dynamic load is proposed in this paper. With the help of the nonlinearly minimum function, viz., fmincon, in MATLAB toolbox, the constrained optimization method for the main parameters of the bearing is studied in order to improve the bearing life.

scholarly journals Power Flows and Efficiency of Output Compound e-CVT

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Francesco Bottiglione ◽  
Giacomo Mantriota
Keyword(s):  
Steady State ◽  
Optimal Design ◽  
Working Conditions ◽  
Hybrid Vehicles ◽  
Short Term ◽  
Vehicle Efficiency ◽  
Variable Transmission ◽  
And Performance ◽  
And Control ◽  
Vehicular Technology

Hybridization is the most promising vehicular technology to get significant improvements of the vehicle efficiency and performance in the short-term. Mechanical transmissions for hybrid vehicles are very often multiple modes transmission, which permit improving the performance in different working conditions. In this context, optimal design and control of these transmissions are a key point to improve the performance of the vehicles, and mathematical models which supports the design can play an important role in this field. In this work, an approach for evaluating the performance of Output Compound Split e-CVT (electric Continuously Variable Transmission) in steady-state is proposed. This approach, in addition to a kinematic analysis of the device, leads to the calculation of the internal power circulation modes and the efficiency of the device in different working conditions.

scholarly journals Modeling the Application Depth and Water Distribution Uniformity of a Linearly Moved Irrigation System

Water ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 827 ◽  
Author(s):  
Liu ◽  
Zhu ◽  
Yuan ◽  
Fordjour
Keyword(s):  
Water Distribution ◽  
Irrigation System ◽  
Simulated Data ◽  
Performance Testing ◽  
Operating Pressure ◽  
Experimental Sample ◽  
Water Application ◽  
Application Depth ◽  
The Individual ◽  
Moving Speed

A model of a linearly moved irrigation system (LMIS) has been developed to calculate the water application depth and coefficient of uniformity (CU), and an experimental sample was used to verify the accuracy of the model. The performance testing of the LMIS equipped with 69-kPa and 138-kPa sprinkler heads was carried out in an indoor laboratory. The LMIS was towed by a winch with a 1.0 cycle/min pulsing frequency while operating at percent-timer settings of 30, 45, 60, 75, and 90%, corresponding to average moving speeds of 1.5, 2.3, 3.3, 4.0, and 4.7 m min−1, respectively. The application depth and CU obtained under various speed conditions were compared between the measured and model-simulated data. The model calculation accuracy was high for both operating pressures of 69 and 138 kPa. The measured application depths were much larger than the triangular-shaped predictions of the simulated application depth and were between the parabolic-shaped predictions and the elliptical-shaped predictions of the simulated application depth. The results also indicate that the operating pressure and moving speed were not significant factors that affected the resulting CU values. For the parabolic- and elliptical-shaped predictions, the deviations between the measured and model-simulated values were within 5%, except for several cases at moving speeds of 2.3 and 4.0 m min−1. The measured water distribution pattern of the individual sprinklers could be represented by both elliptical- and parabolic-shaped predictions, which are accurate and reliable for simulating the application performances of the LMIS. The most innovative aspect of the proposed model is that the water application depths and CU values of the irrigation system can be determined at any moving speed.

Effects of Plate Structure and Nozzle Diameter on Hydraulic Performance of Fixed Spray Plate Sprinklers at Low Working Pressures

2021 ◽  
Vol 64 (1) ◽  
pp. 231-242
Author(s):  
Rui Chen ◽  
Hong Li ◽  
Jian Wang ◽  
Chao Chen
Keyword(s):  
Water Distribution ◽  
Sprinkler Irrigation ◽  
Hydraulic Performance ◽  
Nozzle Diameter ◽  
Water Application ◽  
Working Pressure ◽  
Plate Structure ◽  
Irrigation Uniformity ◽  
Application Depth ◽  
Peak Value

HighlightsThe hydraulic performance of fixed spray plate sprinklers (FSPS) was evaluated at low working pressures.The effects of geometric structure on the hydraulic performance of FSPS were studied.A model was developed for estimating the application depth and uniformity of FSPS under a linear-move system.The recommended values of the most effective sprinkler combination spacing for FSPS are given.Abstract. Reducing the working pressure of sprinklers can effectively reduce the energy consumption of sprinkler irrigation systems. Fixed spray plate sprinklers (FSPS) have a simple structure, and their working pressure has potential to be reduced to 40 kPa. To evaluate the hydraulic performance of FSPS at low pressure, an experiment was conducted to investigate the effects of working pressure, plate structure, and nozzle diameter on sprinkler flow rate, wetted radius, and water application distribution. Two plates (FSPSB and FSPSY) and five nozzles were used in the tests. The cumulative water application depth and irrigation uniformity coefficient were calculated under a linear-move system. The results show that sprinklers with larger nozzle diameters and higher working pressures produce greater coefficients of discharge. The wetted radius gradually increases with the increase in working pressure and nozzle diameter. Two empirical equations for estimating the wetted radius of the two plates are proposed. The FSPSB has a concave trajectory structure that produces a longer wetted radius than the FSPSY, which has a flat trajectory structure. Along the wetted radius, the water application rate increases and then decreases, with a peak value at a certain distance. For the FSPSB, the peak rate of water application decreases with increasing working pressure. However, the FSPSY shows the opposite trend, with the maximum peak value occurring at the highest working pressure of 250 kPa. The water distribution for a single FSPSB sprinkler is discrete due to the greater water dispersal caused by the deeper grooves in the plate. In contrast, a single FSPSY sprinkler provides a more uniform water distribution. The irrigation uniformity of the FSPSY is higher than that of the FSPSB. The recommended values for the most effective sprinkler combination spacings for FSPSB and FSPSY are given in this article. The results may be useful for selecting appropriate sprinklers in hydraulic design procedures. Keywords: Cumulative spray water depth, Irrigation uniformity, Sprinkler irrigation, Water distribution, Working condition.

Contact Analysis between Packer Slips and Casing Based on Abaqus

2013 ◽  
Vol 850-851 ◽  
pp. 262-265
Author(s):  
Yuan Wang ◽  
Quan Jie Gao ◽  
Fei Long Zheng
Keyword(s):  
Finite Element ◽  
Optimal Design ◽  
Working Conditions ◽  
Contact Analysis ◽  
Oil Yield ◽  
Rubber Tube ◽  
Finite Element Software ◽  
Production Safety

The slips on packer play an important role on supporting packer and locking rubber tube after they have been anchored, and their performance directly affects the oil yield and production safety. In this paper, the contact between a type of packer slips and casing is analyzed using the finite element software Abaqus, the stress and displacement fringe graphs of the casing under working conditions are obtained, and it offers the guidance on optimal design for packer slips.

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