Fan Jet Research Articles

JUSTIFICATION OF NOZZLE PARAMETERS OF JET-TYPE WASHING MACHINES FOR CLEANING AGRICULTURAL MACHINES AND UNITS

Agricultural machinery and equipment are exposed to significant contamination by various types of pollutants, some of which can be easily removed, while others require the use of special cleaning agents and machines. To remove these contaminants, a pressurized water jet is used, the biggest disadvantage of such devices is the significant water consumption, so the issue of intensifying the cleaning process of agricultural machinery using a limited amount of water is an important scientific task. Cleaning of agricultural machinery and units from contaminants is a complex technological operation, therefore, there is a need to develop and justify the parameters and operating modes of a high-tech washing device that would ensure high-quality removal of all types of contaminants with high efficiency, minimal water consumption and minimal labor costs. The analysis of cleaning technologies showed that water jet cleaning is the most promising for removing dirt from the surface of agricultural machines and units, the technology allows to increase the level of mechanical impact by using additional energy, which can be the energy of a rotating jet. The study examines the efficiency of cleaning washing plants from various contaminants. The main focus is on studying the impact of nozzle design on the quality and productivity of the washing process. Nozzles determine the shape of water jets and their velocity, determining the cleaning efficiency. The dagger and fan nozzles, their advantages and disadvantages are considered. Nozzle parameters such as orifice diameter, spray angle, and number of fan jets are investigated. It is shown that properly selected nozzle parameters play an important role in achieving the optimal cleaning effect and water saving. Factors such as flow coefficient, drag coefficient, and velocity coefficient that affect the performance and energy of the jet are outlined.

Increasing the efficiency and environmental safety of ship power plants cooling systems with jet heat removal devices

There are numerous cases when during the ship operation it is advisable to exclude for some time the intake of sea water used to cool the ship’s power plant. The issues of the possibility of such operation of widely used open double-circuit cooling systems are considered. To this end, the systems can be switched to the sea water tanks available on board. Work according to this scheme is limited by the time of heating the available water to the maximum allowable temperature. The issues of increasing this time by rising the heat removal through the ship’s plating are considered. To do this, the heated water is not simply discharged into the tank, but is jet supplied through the pipeline system directly to the inner surface of the ship’s plating. Conducted visual and thermal engineering studies have shown that the best results are achieved with the use of a jet supply, supplemented by a screen one. As a result, a channel for hot water movement is formed between the screen and the ship’s plating. Water radially spreads outward from the center of the screen, forming a fan jet. At the same time, the maximum flow velocity around the ship’s plating and the temperature difference between hot and outboard water are ensured. The advantages of this method for supplying cooled water are confirmed by the thermal engineering studies. It is shown that in this case the heat transfer increases by 25…30 %, compared with the case of a simple jet water supply. As a result of processing numerous experimental data, generalizing similarity equations have been obtained. They allow you to calculate the heat transfer for various water flow regimes. The use of these devices allows you to increase the time of systems operation in a closed loop without receiving outside water. These devices are quite simple in design and can be used both at the stage of building a new ship, and when modernizing existing ships. An example of such devices introduction on self-propelled floating cranes is given.

Experimental investigation and numerical modeling for induction fans

Induced ventilation systems have been widely used in the design of underground space architecture; they are used to agitate the air and eliminate the smoke and harmful gases formed by fire. In the application design of induced ventilation systems, most people often use the Computational Fluid Dynamics (CFD)-technique to simulate and study the flow distribution in underground space buildings. However, there has been little research carried out on the performance of the induction fan, which is a key equipment of induced ventilation systems, especially a lack of experimental verification data on the simulation model of the induction fan. In this paper, the performance of a specific type of axial induction fan is measured experimentally, modeled in CFD. The velocity boundary condition method was adopted for the modeling, and the k-w SST model was adopted for the turbulence model. The CFD model is validated using experimental data on velocity distribution along the axis of the fan jet. The experimental results show that, in addition to wind speed along the jet direction, the axial flow induction fan also has a large deflection wind speed in the y and z directions of 3D space at the outlet. The simulation results show that, along the jet direction, within 1.0 m from the fan outlet, when the efflux induced fan outlet was set to Uniform Wind Speed (UWS), Non-Uniform Wind Speed (NUWS) and Spatial Three-Dimensional Wind Speed (STDWS), the simulation results on average velocity along the jet axis were significantly different from the experimental values. At x = 1.0 m, the agreement between the STDWS simulation results and experimental values is about 183% higher than that of NUWS. With the development of the jet flow, the simulation results of UWS are basically consistent with those of NUWS, and the simulation results of STDWS are significantly better than those of UWS and NUWS, which are closer to the experimental values. At the far end of the jet, the three simulation values are in good agreement with the actual measured values, and the simulation values of STDWS are closer to the actual measured values.

Determination of the Application Parameters of Spraying Drones for Crop Production in Hazelnut Orchards

Hazelnut, which has the most common cultivation area after almonds and walnuts among the shell fruits in the world, contains high levels of fat, protein, carbohydrates, various minerals and vitamins. Hazelnut has a broad growing area around the world, and Turkey accounts for 58% of world production with 776,000 tons annually. With this production capacity, Turkey ranks first in hazelnut production over the world. Harmful insects in hazelnut trees are the main factors that reduce hazelnut yield and quality. Pesticides are sprayed with backpack sprayers in the fight against these pests in hazelnut trees. Farmers are directly exposed to pesticides in these practices, which use high amounts of pesticides and water. In recent years, the use of unmanned agricultural vehicles in agriculture has increased. Drones are also used in pesticide applications in agriculture. In this study, the suitability of pesticide applications with the drone in hazelnut fields in Giresun province in terms of field conditions and spraying efficiency was investigated. In September 2021, applications were made with DJI Agras MG-1P model spraying drone in a selected hazelnut orchard in Uzgur village of Giresun province. The drone has 4 Teejet XR11001VS fan jet nozzles. Water-sensitive papers were placed on different regions on the hazelnut trees to be sprayed for drop measurements. In the experiments, hazelnut trees were sprayed using water at different heights and spraying rates. 6 flights were carried out at 1.5 and 2 meters altitudes and 1, 2 and 3 L.da-1 spray rates, and three hazel trees were sprayed as three repetitions in each flight. After the flight trials, the water-sensitive papers were scanned on the scanner, and the volume median diameters and the number of droplets per square centimetre were calculated in the DepositScan software. As a result of the analyses done, it was observed that the applications performed at 1 L.da-1 and 2 L.da-1 spray rates would not be sufficient in terms of spraying efficiency. As the drone flight altitude increased, the accumulation of the drops on the inner leaves decreased. In terms of drop distribution, the most homogeneous application parameter was found to be 1.5 meters high above the upper leaves of the hazel trees and 3 L.da-1 spray rate.

Physical properties of a fan-shaped jet backlit by an X9.3 flare

Context.Fan-shaped jets sometimes form above light bridges and are believed to be driven by the reconnection of the vertical umbral field with the more horizontal field above the light bridges. Because these jets are not fully opaque in the wings of most chromospheric lines, it is not possible to study their spectra without highly complex considerations of radiative transfer in spectral lines from the atmosphere behind the fan.Aims.We take advantage of a unique set of observations of the Hαline along with the Ca II8542 Å and Ca IIK lines obtained with the CRISP and CHROMIS instrument of the Swedish 1-m Solar Telescope to study the physical properties of a fan-shaped jet that was backlit by an X9.3 flare. For what we believe to be the first time, we report an observationally derived estimate of the mass and density of material in a fan-shaped jet.Methods.The Hαflare ribbon emission profiles from behind the fan are highly broadened and flattened, allowing us to investigate the fan with a single slab via Beckers’ cloud model, as if it were backlit by a flat spectral profile of continuum emission. Using this model we derived the opacity and velocity of the material in the jet. Using inversions of Ca II8542 Å emission via the STockholm inversion Code, we were also able to estimate the temperature and to cross-check the velocity of the material in the jet. Finally, we used the masses and the plane-of-sky and line-of-sight velocities as functions of time to investigate the downward supply of energy and momentum to the photosphere in the collapse of this jet, and evaluated it as a potential driver for a sunquake beneath.Results.We find that the physical properties of the fan material are reasonably chromospheric in nature, with a temperature of 7050 ± 250 K and a mean density of 2 ± 0.3 × 10−11g cm−3.Conclusions.The total mass observed in Hαwas found to be 3.9 ± 0.7 × 1013g and the kinetic energy delivered to the base of the fan in its collapse was nearly two orders of magnitude below typical sunquake energies. We therefore rule out this jet as the sunquake driver, but cannot completely rule out larger fan jets as potential drivers.

Numerical analysis of bladeless ceiling fan: An effective alternative to conventional ceiling fan

A ceiling fan is one of the cost-effective alternatives for poverty-ridden societies and tropical countries short on natural resources. However, due to the inherent working principle, a lot of losses occur during electrical to mechanical energy conversion. Apart from losses, other problems associated with conventional ceiling fans are buffeting airflow, internal heating, and dirt accumulation on fan blades. Recently, the idea of a bladeless ceiling fan has been patented which has the potential to resolve most of the issues associated with the conventional fans, however, no details have been shared regarding flow physics and their effectiveness in constrained spaces. In this study, an annular type bladeless ceiling fan is computationally analyzed in a standard empty room (4m × 4m x 4m) environment. Parametric analysis of different design features such as fan radius, height from the ceiling and floor, fan jet width, mass flow rate, and orientations was studied and their effect on the perceived comfort level in terms of velocity spread and average velocities were captured computationally. The results show that the fan height in the close vicinity of ceiling does not affect the flow field in the occupied zones, however, as the fan gets closer to the floor the velocity field in the occupied zone changes due to creation of a strong vortex at the center of floor. Thus, fan installation closer to the ceiling (less than 0.5m from the ceiling) is a preferred choice. With an increase in fan radius from 0.3m to 0.5m, an increment of 33% was observed in velocity spread thus increasing the zone of influence. A finer jet width under the same volume flow rate produces higher velocities across the room e.g. 2 mm jet produces 36% higher average velocities as compared to 4 mm jet, which effectively increases zone of influence. Effect of jet orientation was also studied and a 90° (straight down) orientation produced better overall velocity spread in comparison with 110° and 130° orientation. In comparison with conventional fans, a minimum of 57% increment in velocity spread was recorded for all bladeless fan configurations under consideration in the present work. The flow physics of bladeless fan has prospects for further increment in the zone of influence by optimizing the geometric features in light of present work.

Effect of Feed Speed of Object to be Washed on Washing Effectiveness Using Coaxial Fan Jet

Washing with water jets has been used effectively in various areas in recent years. In this study, a coaxial fan-shaped jet combined with a high-pressure jet is being investigated to improve the washing effect using a fan-shaped jet nozzle. The combination of nozzles and jetting pressure have been studied as washing conditions, and effective jetting conditions are now being shown. In this report, we evaluate the washing effect of a relatively small object coated with a starch-derived thin film on a flat plate, focusing on the feed rate as a washing condition. As a result, we found that increasing the number of washes is more effective than slowing down the feed rate (lengthening the washing time per cycle) for the same washing time (jet impingement duration).

Numerical Simulation of a Periodic Quasi-Switching Mode of Flow around a Conical Dimple with a Slope Angle of 10 Degrees on the Wall of a Narrow Channel Using URANS

The applicability of the solution of the unsteady Reynolds-averaged Navier–Stokes equations (URANS) for the numerical simulation of the periodic quasi-switching regime of vortex generation and heat transfer in a deep conical dimple with a slope angle of 10∘ on the wall of a narrow channel is substantiated. To calculate the turbulent regime, the model of shear stress transfer by Menter 2003, modified taking into account the influence of the curvature of streamlines within the framework of the Rodi-Leshziner-Isaev approach, is used. At Reynolds number Re=104, the oscillation period of the transverse Rz and longitudinal forces Rx, as well as the total heat transfer Numm to the control section of the heated channel wall with a dimple, is set equal to 60, which corresponds to the Strouhal number St=0.0167. Computer visualization of swirling jet-vortex flows demonstrates focus-type sources on the side faces of the dimple. In the self-oscillating mode, a two-cell vortex system is formed with different intensities at the oscillation period Rz. Periodic changes in friction, Nusselt numbers and temperature are recorded in the longitudinal and transverse median sections of the dimple and reflect the oscillations of the vortex structure from left to right and from right to left. The formation of a fan jet is shown, which oscillates relative to the plane of longitudinal symmetry, causing a redistribution of power and thermal loads.

Determination of the optimum operating parameters of an axial fan used on the conventional air blast orchard sprayer

The pesticide droplets are carried to the tree canopy with the assist of the air flow which is generated by an axial fan of orchard sprayer. The designers manufacture the fan of orchard sprayer with ability of 6 different working conditions under constant PTO speed. Previous studies were related to evaluating the effectiveness of sprayers. In this study, 6 different options that presented to farmers was evaluated with view of energy consumption and air flow. A Conventional orchard sprayer having an axial fan with 36” diameter was operated at two fan revolutions (1890 and 2430 rpm) and at three blade angles (15º, 30º, 45º), and measured air capacity, the fuel consumption, variations of air velocities in air jet profile of the fan and calculated power consumption for each operating parameters potentially to be chosen by farmers. As a result, for each blade angle, if the fan speed increase, the air jet of the fan become more uniform than before. The maximum fan efficiency and system efficiency were %73,25 and %59,98 respectively which were obtained 30o blade angle and 2430 rpm fan rotation speed condition. The minimum fuel consumption and torque need was obtained under conditions of 15o blade angle and 1890 rpm fan rotation speed. However, considering maximum air capacity and the best air velocity uniformity in the profile of fan jet was established at, 45o blade angle and 2430 rpm fan rotation speed operating parameters.

Particle image velocimetry and constant temperature anemometer measurements of the jet produced by a centrifugal fan

This article presents a detailed investigation of the three-dimensional flow field produced by a small centrifugal fan used for cooling of electronic components, for instance, in the automotive industry. A particle image velocimetry (PIV) system captured numerous cross sections of the fan jet for analysis of velocity distribution and jet development. General parameters, such as the spreading rate, and flow specifics, such as the full width at half maximum contours in planes parallel to the fan outlet and the jet's rotation rate, were thus evaluated. In addition, constant temperature anemometry enabled a thorough investigation of the flow field at the fan's outflow port. Hot-wire measurements complement the PIV results by providing the power spectral density of the turbulent kinetic energy at several locations. Our results demonstrate that the cross-flow profile at the fan outlet consists of two counter-rotating vortices. This leads to a jet with a nearly elliptical, rotating cross section, which does not propagate in a direction perpendicular to the outlet plane. Several aspects of these distinctive flow features are evaluated and presented to provide both fluid mechanics and heat transfer engineers with (i) data on the air jet produced by a small centrifugal fan and (ii) reference data for computational fluid dynamics simulations. Despite complex flow development in the near field of the jet and the nonaxisymmetric jet contour in the intermediate field, our results are in good agreement with published data on axisymmetric jets in terms of spreading rate and the development of turbulence spectra observed in the intermediate field.

ОСОБЕННОСТИ ВЕНТИЛЯЦИИ ЗРИТЕЛЬНЫХ ЗАЛОВ

The choice of air distribution scheme is the most important task which determines indoor air quality, comfort thermal mode of the room and effectiveness of ventilation systems. The article presents comparative analysis of displacement and mixing ventilation systems for large premises. The methodology of the study is based on existing theoretical provisions and standard calculation approach of supply air jets. Multivariate calculations of mixing air distribution in cinema hall are presented. Horizontal jets along room surfaces can not provide required air velocity. In the case of vertical air distribution relative jet area beyond the recommended values. This factor had thus determined the possible formation of circulation contours with high concentrations of harmful emissions. The results of the calculation shows that the speed of the fan jet at the entrance of occupied zone lower than maximum permissible air mobility. The required temperature is achieved by using all air-distributing units considered.

Experimental and numerical study of heat transfer characteristics of single-phase free-surface fan jet impingement with automatic transmission fluid

Due to the ever-increasing power density of the advanced electric machines (motors/generators) in electric vehicles and hybrid electric vehicles, thermal management of electric machines has become increasingly critical to permit high power output, enhanced reliability, and miniaturization. The cooling of electric machines is mostly accomplished by depositing fluids or oils directly onto the machine's coil windings to remove the excessive heat. As an efficient approach of direct cooling, jet impingement has been attracting significant attention from researchers and industry due to the high heat transfer rates and large cooling capacity. In this work, we present a study of fan jet impingement of automatic transmission fluid (ATF) on a target surface with a constant heat flux. Experiments were carried out with ATF temperatures varying from 50 °C to 90 °C and flow rates varying from 1 × 10−5 to 2.5 × 10−5 m3/s to encompass potential operating conditions within the automotive transaxle environment. A numerical model of the test section was developed and validated with experimental results and used to investigate the influence of flow parameters and nozzle geometry on the heat transfer characteristics of the impinging fan jet. Major controlling parameters studied in this work include flow rate, fluid temperature, nozzle-to-target distance, and incidence angles. Average heat transfer coefficients are calculated as the major metric to compare the impact from various controlling parameters. Correlation of flow and heat transfer characteristics of fan jet impingement is explored within the scope of this work. In addition, heat transfer coefficient results of fan jet impingement are compared with the circular jet, which is commonly applied to cool electric machines. At all flow velocities, circular jets yield heat transfer coefficients 20%–25% higher than those obtained from the fan jet impingement.

Spray nozzles, working pressures and use of adjuvant in reduction of 2,4-D herbicide spray drift

Background: The study of the interactions between equipment, application methods, and spray mixtures is fundamental to optimize the application of pesticides. The determination of the best combination of these factors can reduce the drift during the application of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D). Objective: The objective this paper is to study the influence of nozzle models, working pressures, and surfactant adjuvant in reducing the drift of 2,4-D. Methods: The spectrum of nozzle drops was determined for a conventional flat jet; flat jet with air induction; double plane jet with air induction; deflector flat jet with air induction; and an empty cone with air induction at pressures of 200, 300, 400, and 500 kPa. This was quantified in a wind tunnel with four drifts: water; water + surfactant adjuvant; water + 2,4-D; and water + 2,4-D + surfactant adjuvant, applied by the five nozzle models at four working pressures. The data was evaluated by analysis of variance and, when significant, by the Tukey test and regression at 5% significance level. Results: The interactions between the nozzle models, working pressure, and spray mixture directly influenced the 2,4-D drift. Conclusions: The use of surfactant adjuvant must be carried out carefully, according to the nozzle model, working pressure, and spray mixture. The conventional single fan jet nozzle is more sensitive to increased working pressure and has a high potential to cause drift compared with the models with air induction.

Effect of turbulence modeling for the prediction of flow and heat transfer in rotorcraft avionics bay

In this paper, four turbulence models are compared on the basis of the predictions they produce for the flow and heat transfer in the avionics bay area of a rotorcraft. The turbulence models studied are the standard k-ε, Renormalization Group (RNG) k-ε, realizable k-ε, and Shear-Stress Transport (SST) k-ω model. The avionics bay used in the study houses avionics equipment mounted on the floor and on a rack inside the bay to mimic a realistic distribution of equipment in actual rotorcraft. The avionics bay incorporates a cooling system consisting of a fan that intakes ambient air via a forced-convection method and an exhaust, with the purpose of keeping the avionics equipment temperatures below their operational limits. The turbulence levels, flow and thermal fields are investigated and compared in order to quantify the differences between the predictions of the turbulence models used in computations. It is observed that the use of the standard and realizable k-ε models mostly produce similar flow and thermal results across the bay area, while the largest differences between the predictions are found with the RNG k-ε and the SST k-ω turbulence models especially at the locations in the vicinity of the fan impingement. Comparing the avionics equipment surface temperature predictions, the standard and realizable k-ε turbulence models are observed to produce slightly more conservative results. The average variation between the surface temperature predictions by all models is less than 3.5 K, indicating that this parameter is considerably insensitive to the selected turbulence model. A close examination of the fan jet region starting from the fan inlet revealed generally similar predictions of flow and thermal features by all turbulence models. The maximum variation in the velocity and temperature predicted by all turbulence models is 2.2% and 0.1% of the fan inlet conditions, respectively. Large differences in turbulence intensity were observed depending on the location downstream of the fan jet and the turbulence model used.

AERODYNAMICS OF JETS INTERACTING WITH A FLAT SURFACE

In this paper, the development features of a single free jet of hightemperature nitrogen interacting with a flat surface were studied. Calculation of the heat exchange process during heating by the attacking jets is very difficult to implement analytically due to complexity of the gas-dynamic processes occurring both in a single jet and in a system of jets interacting with the metal. The computational difficulties are aggravated by the fact that when interacting with the surface the jet as such disappears. The flat (fan) flow interacts with the surface: form, aerodynamic properties and thermal state of the flow strongly differ from those of the original jet. The studies were conducted on the basis of numerical simulation in the FloEFD software and computing complex for multiphysical simulation based on solution of the equations of gas dynamics and heat transfer. The solved system of equations consisted of Navier-Stokes equations, equations of energy and continuity and was supplemented by k – ε turbulence model. A three-dimensional model was developed for simulation, the necessary properties, initial and boundary conditions were specified. In the study of aerodynamics of a single high-temperature jet interacting with the surface, the main defining values were: nitrogen flow rate from the nozzle U0 , nitrogen temperature T, internal diameter of the nozzle d0 , distance from the nozzle section to the surface h, distance from the critical point (point of intersection of the jet axis with the surface) along the flow radius r. Data on the gas velocity decrease as the jet develops due to the loss of initial energy to engage the motionless surrounding gas in motion, is presented. The studies have shown that increase in the initial velocity of gas outflow brings the area of higher velocities closer to the surface both in the jet itself and in the fan jet. This factor contributes to heat transfer intensification. In addition, high speeds increase the total thickness of the fan flow and reduce the thickness of hydrodynamic boundary layer, which increases with distance from the critical point.

Numerical Investigation of Powered Jet Effects by RANS/LES Hybrid Methods

For the high-precision simulation of engine jet effects, an improved delayed detached eddy simulation (IDDES) method based on the two-equation shear stress transport (SST) model is developed, and the fifth-order finite-volume weighted essentially non-oscillatory (WENO) scheme is employed to enhance accuracy of spatial discretization, and then numerical investigation of powered jet effects by RANS/LES hybrid methods is carried out. The effects of the grid distributions and the accuracy of the spatial schemes are discussed during the RANS/LES validation analysis on the fully expanded jet flow and Acoustic Reference Nozzle (ARN) jet flow. The results show that, by enlarging the grid density and improving the accuracy of the spatial schemes, the velocity distributions in the jet flow can be better predicted, the non-physical steady flow after the jet nozzle can be shortened, the instantaneous flow structures are clearer and the turbulent intensities are more accurate. Then IDDES simulation of turbofan engine jet flow is carried out. The mixing characteristics of the external fan jet flow and internal core jet flow as well as the ambient flow are obtained, and the three-dimensional turbulent structures are also given.

Transient Analyses and Energy Balance of Air Flow in Road Tunnels

The issue of airflow dynamic in a road tunnel is considered in this study and its impact on smoke management and people safety is highlighted. It was an attempt to estimate the time needed to reach a final steady state of airflow when the operation mode of jet fans was switched. The numerical model of the tunnel was solved with the use of Ansys Fluent. To reproduce the decrease of atmospheric pressure with height, relative static pressure was applied using UDF (User Defined Function). The ambient weather conditions were taken into account as well. The wind influence was introduced by the additional component of dynamic pressure applied against one of the tunnel portals also using UDF. There are some theoretical foundations of airflow in a tunnel presented in this paper. The obtained results were compared with the measurements carried out in a real road tunnel and the results obtained while applying the above-mentioned physical model. The main contribution of the presented work is the indication of a relatively high relaxation time of airflow in a tunnel, which could be important when designing the emergency pattern of a ventilation system. Additionally, some considerations of kinetic energy exchange between fan jet and air volume would be helpful when choosing fans for ventilation systems being designed.

ЭКСПЕРИМЕНТАЛЬНЫЕ УСТАНОВКИ ДЛЯ ОПРЕДЕЛЕНИЯ УСЛОВИЙ РЕАЛИЗАЦИИ КОАНДОВСКИХ ТЕЧЕНИЙ

The Coanda effect has become widely used in ventilation, power engineering and aviation. This paper is devoted to experimental installations for determining the conditions for implementing two-dimensional and three-dimensional, plane and axisymmetric Coanda flows. The main prerequisites and results of the research are presented, including the foreign (Newman B.G., Carpenter P.W., Bradshaw P., Patankar U.M., etc.) and domestic (Sokolova I.N., Zhuleva Yu.G., Kvashnina I.M. et al.) researchers. In view of these, a laboratory bench was designed to test the efficiency of the device for reducing dust formation during the loading of bulk materials. The response function and the factors influencing the implementation of the Coanda effect in the formation of a fan jet in the approximate technological conditions of the pneumatic transport loading of bins with powder materials have been determined, and a plan for a multifactor experiment has been compiled. The results of a searching experiment confirming the operability of the proposed device and the need for further studies of design-mode characteristics are presented.

Ceiling fan air speeds around desks and office partitions

Ceiling fans may cool room occupants very efficiently, but the air speeds experienced in the occupied zone are inherently non-uniform. Designers should be aware of several generic flow patterns when positioning ceiling fans in a room. Key to these are the fan jet itself and lateral spreading near the floor. Adding workstation furniture redirects the jet's airflow laterally in a deeper spreading zone, making room air flows more complex but potentially increasing the cooling experienced by the occupants.This paper presents the first evaluation of the effects of tables and workstation partitions on a room's generic air flow and comfort profiles. In a test room with a ceiling fan, we moved five anemometers mounted in a “tree” at heights of 0.1, 0.6, 0.75, 1.1, and 1.7 m to sample a dense measurement grid of 7 rows and 6 columns. We tested five different table and partition configurations and compared them to the empty room base case. From the results we propose a simplified model of room airflow under ceiling fans, useful for positioning fans and workstation furniture. We also present comfort contours measured in two ways that have comfort standards implications. The measured data are publicly available on the internet.

PRODUCTION AND QUALITY ENHANCEMENT OF MANGO USING FAN JET SPRAYER IRRIGATION TECHNIQUE

<p>Lack of water in reproductive phases (flowering, fruit formation and maturation) of mango can reduce fruit production and quality. In these phases the plant must be protected from water stress. The aim of the research was to assess the effect of irrigation on the productivity and quality of mango fruits. The study was conducted at the Cukurgondang Experimental Station, Pasuruan, East Java, from April to December 2013, using 40 mango trees of 21 year-old Arumanis variety. Mangoes were planted on five rows with eight plants for each row and 6 m x 6 m spacing within the row. Fan jet sprayer irrigation was installed using hose according to plant diameter. The irrigation technique of fan jet sprayer with four nozzles per plant was applied at 125, 100, 75, 50 and 0% of crop water requirements or equal to 828, 663, 497, 331 and 0 liters of water per tree, every seven days. The parameters observed were the number and weight of fallen fruits and the number, weight and quality of mangoes harvested. The results showed that irrigation of 50% and 75% of crop water requirement had the highest and lowest number of fallen fruits (26% and 14% of total production), respectively. The highest and lowest total number of mangoes were 3.108 and 1904 fruits, respectively, which were achieved at irrigation of 50% and 75% of crop water requirement. Further, the highest and lowest total weight of mango fruits were 1036.2 and 677.9 kg respectively which were achieved at irrigation of 50% and 125% of crop water requirement. Mango fruits produced were dominated by grades 2 and 3 with A quality.</p>