Design and Test of a Jet Remote Control Spraying Machine for Orchards

Aimed at issues associated with the poor air supply and poor automatic targeting accuracy of existing orchard sprayers, this paper designs a jet-type orchard remote control sprayer with automatic targeting which is suitable for standardized orchards in hilly and mountainous areas. By optimizing the structure of the diversion box, the uniformity of deposition and penetration ability of the pesticide droplets to the fruit tree canopy are improved, and a uniform wild field distribution is realized simultaneously. An accurate positioning of the fruit tree canopy space orientation is achieved through automatic targeting and azimuthal adjustment systems. When the target is detected, the solenoid valve is controlled to open, and vice versa, and the distance from the nozzle to the fruit tree canopy is adjusted in real time to improve the utilization rate of pesticides. The test results show that the effective range of the jet-type orchard remote control sprayer is no more than 3.5 m, and the maximum flow rate range is 6~6.5 L/min. Within the effective spraying range, the farther the distance is, the higher the automatic targeting accuracy. The pesticide droplets sprayed by the spraying machine have a certain penetration ability, and the uniformity of the droplets is good, which solves solidification problems caused by the penetration of pesticide into the soil. This research provides a reference for jet spraying operation and automatic targeting spraying structure design.

Challenges of numerical modelling and simulation of flow inside the hydraulic tank

The basic purpose of the hydraulic tank is to hold a volume of fluid, transfer heat from the system, allow solid contaminants to settle and facilitate the release of air and moisture from the fluid. To perform these important tasks more efficiently, the tank must be properly dimensioned and it must operate in correct flow rate range. At high flow rates it can be subjected to effects of turbulence, leading to poorer performance of the tank. To predict turbulent effects correctly a numerical simulation, based on RANS approach is prepared and run. Difference between k-ε model and k-ω Shear Stress Transport (SST) is investigated and results are presented. Impact of choice of turbulence model is discussed.

Magnetic Polymer Based Micropumps for Microfluidic Sample Delivery System

In this paper we present the development of electromagnetic (EM) microfluidic pumps incorporating the magnetic polymer composite for the transport of microfluidic bio-sample. The pump system includes the electromagnetic field generator, a flexible actuator membrane made of polymer material with embedded magnetic particles and valve-less microfluidic channel and chamber. The micropump is fabricated using a MEMS process with additional bonding process. Various types of the magnetic membrane as well as electromagnetic coils were fabricated and characterized to find optimum pump performance. As the results, it is found that the fabricated pump systems were able to deliver fluidic sample within a large flow-rate range from 6 ml/min down to several nl/min which can be adjusted by setting the input electrical current parameters, such as intensity, frequency and type of the current signal.

Laboratory Tests of New Groundwater Table Level Regulators in Subsurface Drainage Systems

The changes in hydrological conditions observed nowadays require economical use of water. This applies to water management both on a national scale and river basins and catchments, as well as on the scale of drainage systems and individual drainage networks. Outflow regulation is carried out by extending the outflow time of surface water collected during rainfall in various forms of retention in the catchment area. One of the devices for regulating the outflow of groundwater is a drainage network, traditionally used as a drainage system. The water level regulators presented in this article enable the damming of water in the drainage network, in pipelines and in the adjacent ground. The conducted tests were aimed at determining the hydraulic characteristics and operating conditions of two innovative solutions of water level regulators in drainage systems. These regulators are characterised by the possibility of smooth regulation by the use of rotary or propeller systems for smoothly setting the damming level. Both tested regulators are characterised by the presence of an effective flow, the value of which was set at the level of Qe = 0.17 l∙s−1 to Qe = 0.25 l∙s−1 for the funnel regulator and Qe = 0.009 l∙s−1 to Qe = 0.015 l∙s−1 for a hole regulator. Laboratory tests of the prototypes showed that the funnel regulator allows one to maintain the damming level in a flow rate range of up to 5.5 l∙s−1, with possible damming up to 3 cm, regardless of the height of the shaft. The hole regulator is characterised by a flow control range of up to Q = 0.65 l∙s−1, greater variability of the damming levels and the need to change the position of the working openings, depending on the flow rate.

Characterization and Validation of the Second-generation wPUM Topography Monitors

Introduction Little is known about the natural use behavior of new and emerging tobacco products due to the limited availability of reliable puff topography monitors suitable for ambulatory deployment. An understanding of use behavior is needed to assess the health impact of emerging tobacco products and inform realistic standardized topography profiles for emissions studies. The purpose of this study is to validate four monitors: the wPUM cigalike, vapepen, hookah, and cigarette monitors. Aims and Methods Each wPUM monitor was characterized and validated for range, accuracy, and resolution for puff flow rate, duration, volume, and interpuff gap in a controlled laboratory environment. Monitor repeatability was assessed for each wPUM monitor using four separate week-long natural environment monitoring studies including cigalike, vapepen, hookah, and cigarette users. Results The valid flow rate range was 10 to 100 mL/s for cigalike and cigarette monitors, 10 to 95 mL/s for vapepen monitors, and 50 to 400 mL/s hookah monitors. Flow rate accuracy was within ±2 mL/s for cigalike, vapepen, and cigarette monitors and ±6 mL/s for the hookah monitor. Durations and interpuff gaps as small as 0.2 s were measured to within ±0.07 s. Monitor calibrations changed by 4.7% (vapepen), 1.5% (cigarette), 0.5% (cigalike), and 0.1% (hookah) after 1 week of natural environment use. Conclusions The wPUM topography monitors were demonstrated to be reliable when deployed in the natural environment for a range of emerging tobacco products. Implications The current study addresses the lack of available techniques to reliably monitor topography in the natural environment, across multiple emerging tobacco products. Natural environment topography data will inform standardized puffing protocols for premarket tobacco product applications. The ability to quantify topography over extended periods of time will lead to a better understanding of use behavior and better-informed regulations to protect public health.

Design Optimization of Splitter Blade Impeller in a Centrifugal Pump

In order to improve suction performance, centrifugal pumps with an inducer are used for rocket pumps, liquid gas transport such as LNG, and general-purpose pumps. Since a higher suction performance than conventional pump is required, a splitter blade that consists of a long blade and a short blade is sometimes adopted. However, the design becomes more difficult due to the increased number of parameters. The stable operation over a wide flow rate range are required in the general-purpose pumps. Therefore it is necessary to design them so that unstable flow phenomena such as surges do not occur. However, the design method to avoid them is not well understood yet. In this study, we focused on the splitter blade impeller in a general-purpose low-speed centrifugal pump with an inducer. Six parameters such as leading edge position and trailing edge position of the short blade for both hub-side and tip-side were set as design ones. A multi-objective optimization method using a commercial software was applied to improve suction performance while maintaining high efficiency. Then obtained optimal shape were analyzed by CFD calculation and extracted the feature. Furthermore, optimized impellers were manufactured and confirmed the performance over a wide flow rate range by experiments. In addition, a optimizing design method that improves pump performance at lower cost was studied.

Validation of Calculated Pressure Drop Using Experimental Data with Standard Methods of an Existing Software

The aim of this research was to determine the pressure drop along a 450 km long multiproduct pipeline. Empirical formulae and quantitative methods were applied in order to establish pressure drop as an operating parameter. Flow rates used were obtained from the daily operation records of two consecutive years and were in the range of 629 – 765 m3/hr. Using four methods, observed pressure drop results when pumping products through the pipeline were as follows: Shell-MIT was 954.5 – 1411.9 bar (gasoline), 1257.6 – 1860.3 bar (kerosene) and 1535.0 – 2270.5 bar (diesel); Benjamin Miller was 0.509 – 0.728 bar/km (gasoline), 0.693 – 0.988 bar/km (kerosene), 0.773 – 1.101 bar/km (diesel); T. R. Aude was 0.590 – 0.841 bar/km (gasoline), 0.814 – 1.161 bar/km (kerosene), 0.907 – 1.294 (diesel); Darcy was 0.578 – 0.857 bar/km (gasoline), 0.703 – 1.042 bar/km (kerosene), 0.858 – 1.272 bar/km (diesel). Simulations using pipe-flow wizard were carried out in order to authenticate the calculated parameters. Results confirmed that Shell-MIT method is only applicable to crude oil pipelines. From comparison of calculated pressure drop, Benjamin Miller’s method was most preferred as it observed the least value within the same flow rate range. Simulation results validated the calculated pressure drop and therefore, calculated Benjamin Miller’s and T. R. Aude’s values are recommended for use in further review study of the said pipeline.

Magnetic manipulation on the unlabeled nonmagnetic particles

This paper reports two basic microfluidic strategies for the magnetic manipulation of unlabeled nonmagnetic particles/cells. One is the deflection induced by a single magnet, and the other is the confusing effect produced by two magnets of opposite polarity. They can be combined into more completed particle manipulations like continuous flow separation, counting and detection, which are essential steps in biomedical applications. We experimentally studied the dynamics of 10.4 and 20 [Formula: see text]m nonmagnetic polystyrene particles within a flow rate range of 30, 50, 70 and 90 [Formula: see text]L/min in a straight channel. We defined the cross-section length that the particles occupy as the “particle bandwidth” to characterize the extent of deflection and focusing. To predict the trajectories of the particles, we established a simple theoretical model by considering the magnetic force and viscous drag force. Compared with the experimental results, the maximum deviation of the simulation is 9.28%. The influences of magnetic nanoparticle concentration, magnetic field parameters, size of microparticles and flow rate are systematically investigated. We also demonstrated that the effective deflection and focusing could be realized at low Fe3O4 nanoparticle concentrations, which means that this method can reduce the damage on cells in the practical applications.