Xingye Zhu

Effect of Sprinkler Head Geometrical Parameters on Hydraulic Performance of Fluidic Sprinkler

AbstractA new prototype of fluidic sprinkler is proposed in this paper. To determine the discharge coefficient (A), pattern radius (B), sprinkler rotation speed (C), droplet diameter distribution (D), and the radial application pattern (E), several sprinkler heads were specially fabricated to carry out the experiments. After systematic experiments were conducted with the 10PXH fluidic sprinkler, the results showed that the inner contraction angle influenced A, B, C, and E, and the geometrical parameters of offset length and working area length influenced E. The operating pressure influenced B, C, D, and E. The reductions in the radius exactly corresponded to the reduction of the discharge coefficient. As the inner contraction angle increased from 10° to 70°, the pattern radius at 250xa0kPa decreased from 10.7 to 8.4xa0m and the discharge coefficient decreased from 0.9 to 0.67. The time per rotation and the droplet diameter distribution were analyzed, respectively. The radial application pattern at 250xa0kPa for...

Comparison of fluidic and impact sprinklers based on hydraulic performance

A comparative study of an outside signal sprinkler (OS), a fluidic sprinkler (FS), and an impact sprinkler (IS) was carried out. The OS, FS, and IS were evaluated individually under indoor experimental conditions. Water distribution evaluations were measured under four operating pressures at a 1.5-m nozzle height (above the ground). Approximately 36 individual trials were performed. The results show that the discharge coefficient of the OS and FS was slightly larger than that of the IS. The water distribution profiles of the OS, FS, and IS were parabola-shaped, ellipse-shaped, and doughnut-shaped, respectively. The wetted radius for the OS was similar to the wetted radius of the FS and was 8.7–12xa0% less than the IS. An accurate and simple empirical equation for the wetted radius of OS and FS is reported. Additionally, equations of water application rate, with regard to distance from the sprinklers, are given. The average coefficients of determination for the OS, FS, and IS were 91.8, 89.2, and 79.1xa0%, respectively. Individual spray sprinkler water distributions were mathematically overlapped to calculate the combined uniformity coefficient (CU). Maximal combined CUs of 80.88, 80.92, and 78.12xa0% were found for the OS, FS, and IS, respectively. Both the OS and FS were found to have greater CU values than the IS, which indicates that the OS and FS provided a better water distribution pattern than the IS at low pressure.

METHOD FOR ACHIEVING IRREGULAR BOUNDARY AREA FOR COMPLETE FLUIDIC SPRINKLER

For resolving the problem of sprinkle repeated, overtaken and went beyond in irrigation, it is important to research the approach of irregular boundary area. The equation of range and flow for achieving the square and triangle spray were deduced. Pressure is proportional to range. Specific method of changing the sectional area was put forward for achieving square and triangle spray. Adopted MATLAB language editor to analyzing the theoretical relation and emulate for achieving square and triangle spray. The experiments of theory pressure were carried out. The results showed that the experimental value were consistent with the theoretical value.

Strategy of Energy-saving for Variable-Rate Irrigation Sprinkler

The energy requirement for variable-rate irrigation sprinkler was analyzed. Boundary equations for triangular irrigation were set up. The relationships between irrigated angle, flow-rate and wetted diameter were included. Based on them, the relationship between flow-rate and variable pressure head for variable-rate irrigation system was obtained. Structural diagram and systematic transfer function were established by the technology of frequency control. Simulated programs were established using MATLAB. It supplied theoretical foundation for energy-saving experimental verification of variable-rate irrigation sprinkler for the future.

Comparison of droplet distributions from fluidic and impact sprinklers

To adapt to the trend toward low-energy precision irrigation, the droplet distributions for two new prototype sprinklers, outside signal sprinkler (OS) and fluidic sprinkler (FS), were compared with impact sprinkler (IS). A laser precipitation monitor was used to measure the droplet distributions. Droplet size and velocity distributions were tested under four operating pressures for nozzles 1.5 m above the ground. For the operating pressures tested, the mean OS, FS and IS droplet diameters ranged from 0 to 3.4, 0 to 3.5, 0 to 4.0 mm, respectively. The mean OS and FS droplet velocities ranged from 0 to 6.3 m

Numerical Simulation for Complete Fluidic Sprinkler

s, whereas IS ranged from 0 to 6.3 m

IRRIGATION UNIFORMITY WITH COMPLETE FLUIDIC SPRINKLER IN NO-WIND CONDITIONS

s. Being gas-liquid fluidic sprinklers, droplet distributions of the OS and FS were similar, although not identical. IS mostly produced a 0.5 mm larger droplet diameter and a 0.5 m

Wall-attachment fluidic sprinkler

s greater velocity than OS and FS. A new empirical equation is proposed for determination of droplet size for OS and FS, which is sufficiently accurate and simple to use. Basic statistics for droplet size and velocity were performed on data obtained by the photographic methods. The mean droplet diameter (arithmetic, volumetric and median) decreased and the mean velocity increased in operating pressure for the three types of sprinkler.

Variable-spray whole-torrential flow showerhead

The complete fluidic sprinkler was originally created by China. No numerical simulation study in the sprinkler could be found in recent literature research paper The mathematical model for the inner flow of the complete fluidic sprinkler was established using computational fluid dynamics for the first time. The flow-pressure relationship and wall inclination of the main jet had been simulated. The calculated results were compared with the experimental results. The results of theoretical analysis, experiments and numerical simulation were in good agreement.

Orthogonal tests and precipitation estimates for the outside signal fluidic sprinkler

The Complete fluidic sprinkler was originally created by China. Irrigation uniformity in no-wind conditions was studied in this paper. Radial water distribution for complete fluidic sprinkler type 10 was got by experiment. MATLAB was used to establish computation program to change the radial data into net data. Three-dimensional water distribution figures for single sprinkler and combined sprinklers were figured out after the calculation of MATLAB. Combined uniformity coefficient of the complete fluidic sprinkler type 10 was simulated in combined spacing coefficient form 1 to 1.8.The maximal uniformity coefficient was 80.5% or 88.2% for rectangle or triangular combination respectively. Combined uniformity surpasses 75% when combined spacing coefficient was 1 to 1.7 in rectangle combination and 1.4 to 1.7 in triangular combination. A case study shows that the MATLAB is reliable for simulating water distribution in sprinkler irrigation.