Deflector Angle Research Articles

The Effect of Deflector Angle on the Performance of Turbine Combination Darrieus-Savonius

The Savonius and Darrieus are vertical-axis wind turbines. This turbine has resistance on one side of the blade that makes it difficult for the shaft to rotate resulting in reduced efficiency. However, the vertical shaft turbine type provides the advantage of being able to accept wind speeds from any direction without an additional tail. Savonius and Darrieus turbines show different characteristics in terms of their performances. Savonius turbine has a high power coefficient (CP) in the range of low tip speed ratio (TSR), when its TSR increases the CP will fall. In contrast to Darrieus, high CP is achieved if the TSR is also high but the CP achievement will fall at a low TSR. If it is compared to Savonius, Darrieus has higher power efficiency although it is difficult to self-start. In contrast to Savonius, Darrieus has a better self-starting ability but a lower efficiency. This study aims to improve the performance of vertical shaft wind turbines by creating a new design combination of Darrieus and Savonius turbines with deflectors to produce CP achievement on a wide TSR. The combination of the Darrieus-Savonius turbine is to improve efficiency to make self-start easier. The research method uses numerical simulation by employing CFD Ansys software. On the airfoil with a deflector angle of 70 deg, it shows that there is an increase in speed in several parts of the Darrieus blade airfoil. The increase in speed causes the decrease of static pressure in the area. The pressure difference between the sides of the airfoil surface causes a force. The direction of the force causes the turbine shaft to rotate. The deflector acts as a directional headwind, increasing the local flow velocity to counter the resistance on one side of the rotor blades The average torque produced at an angle of 70 deg is 0.5 Nm. Whereas, at an angle of 90 deg, the average torque generated is lower by around 0.15 Nm.

Improving vertical-axis wind turbine performance through innovative combination of deflector and plasma actuator

Vertical-axis wind turbines (VAWTs) are efficient tools for harvesting wind energy, especially in urban areas; however, aerodynamic losses owing to dynamic stall and negative torque reduce their efficiency. Therefore, it is necessary to use flow-control methods for VAWTs. In the present study, a two-dimensional VAWT is numerically modeled and simulated. Subsequently, a novel combined actuator is proposed to improve the performance of VAWT. This novel combined actuator included plasma actuators and deflector plate as active and passive actuators, respectively. First, 16 cases were examined to determine the optimal deflector angle and distance. In the best case, the deflector with an angle of 45° and a radius ratio of 3.3 increased the power coefficient by 13.37% compared to the open rotor. Then, the effect of the combined use of the deflector and plasma actuator was investigated. The results showed that the activation of the plasma actuator from an azimuth angle of 55° to 145° increased the power coefficient by 45.68% in comparison to the open rotor. Considering the energy consumed by actuators, the net energy produced by the VAWT per rotation cycle increased by 26.72% compared to the open rotor.

Optimizing Vertical-Axis Wind Turbine Performance and Determining Optimal Velocity and Deflector Configuration Based on Wind Speed

In the realm of wind energy harnessing, Vertical-axis Wind Turbines (VAWTs) have emerged as promising alternatives. However, they face persistent challenges due to their low efficiency and poor self-starting properties. This study addresses these limitations and aims to unlock the full potential of VAWTs by conducting a comprehensive investigation. The focus of this research lies in determining the optimal operating velocities to enhance the performance of Savonius-type VAWTs, leveraging advanced deflectors. The study delves into an in-depth analysis of the optimal deflector distances and angles for the turbine, taking into account different geographical areas with varying wind velocities. To achieve this, a Savonius-type VAWT equipped with advanced wind deflectors was meticulously designed and tested. Utilizing SOLIDWORKS software, sophisticated turbine models were crafted, which were then subjected to rigorous analysis using ANSYS Fluent, Computational Fluid Dynamics (CFD) software. The research methodology involved conducting simulations across a range of wind velocities, spanning from 1 ms-1 to 8 ms-1, and changing the deflector distance from 100 cm to 150 cm from the centre of the turbine, and the deflector angle from 12 to 45 degrees. During the simulations, critical indicators of turbine performance, including moment coefficient, moment, force coefficient, and force acting on the blade, were closely examined. The study uncovered significant variations in the power output of the Savonius-type vertical-axis wind turbine (VAWT) fitted with an advanced deflector system, especially at lower wind speeds. Notably, the study revealed that at different wind velocities, the optimum deflector configuration changed, with the highest energy-generating capacity observed at 1 m/s for the wind turbine equipped with advanced deflectors. Outperforming the turbine lacking a deflector system, this inventive method demonstrates the capacity to notably boost energy generation. This novel method underscores the capacity for substantial improvements in energy production. Additionally, the research offers valuable insights into customized deflector distance and angle combinations, optimizing turbine performance for specific wind velocity ranges. By strategically positioning the deflectors, higher energy output can be achieved, making the VAWT system more adaptable and efficient across diverse wind conditions
 
 Keywords: Vertical-axis wind turbine, Wind deflectors, Computational Fluid Dynamics, SOLIDWORKS, ANSYS Fluent

Study on heat transfer performance of spiral fin plate collector

As an important equipment for solar thermal utilization, solar collector is the key to improve energy efficiency and reduce carbon emissions. However, in order to improve the heat transfer capacity of solar collectors, further optimization of their design and performance is the focus of current research. Although the addition of traditional ribs strengthens the lateral air flow, it also increases the heat transfer cavity between the heat transfer mass and the heat absorbing plate. Therefore, in this paper, a new spiral finned flat plate collector is designed from the perspective of the synergistic flow of the heat exchanger mass in the transverse and longitudinal directions. The flow and heat transfer mathematical model of the new collector is established, and numerical simulations are carried out to analyze the effects of the ribbed deflector width and spiral pitch on the collector efficiency. The results show that the heat transfer capacity of the new collector is significantly higher than that of the flat plate collector. In addition, for the spiral rib with a rib height of 38 mm and a diameter of 25 mm, the optimal deflector width is 16 mm, the spiral pitch is 160 mm, and the deflector angle is 33.92?.

Design and performance test of series underwater Savonius rotors with horizontal axis

<span lang="EN-US">The energy of river water flow or irrigation canals can be utilized by using a horizontal axis Savonius turbine, which converts low-speed river flow into electrical power with good design. The design of this turbine needs to pay attention to several parameters, namely, the deflector angle, the number of blades, the diameter and thickness of the blades, and the diameter and thickness of the end plates. However, the problem usually encountered is imperfect turbine construction due to the large drag force that occurs so that the power generated is low. Based on this background, it is proposed to manufacture and test the performance of a series Savonius underwater rotors with a horizontal axis. The research results found that the generator voltage without load was 25.6 V when the turbine only rotated at 47.2 rpm, whereas when under load, the average power produced was 8.5 watts with an average turbine speed of 31 rpm. The highest efficiency value on the rotor is 86.73%, with a torque value of 3.36 at a turbine speed of 29.9 rpm. This indicates that the tool can generate large torque at low speeds.</span>

Effect of using deflector in the distributor head of a pneumatic seed drill on the oat seed sowing unevenness

This paper presents an innovative solution for a distributor head equipped with a deflector (controlled plate)—intended to change the tilt angle (realignment) of the pneumatic seed drill distributor head cover. We compared two qualitative parameters of seed sowing, coefficient of variation and coefficient of lateral unevenness of seed sowing (δ). Values were obtained on the test stand with an innovative deflector built into the distributor head at three angles of inclination (0°, 5° and 10°). Statistical analyses revealed a significant effect of airflow velocity and deflector angle, which corrects the deviation from the vertical plane of the distributor head, on the uniformity of seed sowing. In addition, regression equations were determined to predict the quality of the seed sowing process. The developed and manufactured innovative distributor head with a deflector that tilts in two planes, designed to improve the distribution evenness of the air stream transporting seed to individual coulters in pneumatic seed drills, received a positive review. The use of a deflector with automatic control of its position angle, correcting the deviation of the distributor head from a vertical plane in pneumatic seed drills improves the uniformity of seeding. Therefore, it is reasonable to use this solution for new pneumatic seed drills and those in use on soils with different relief (undulating surface). Moreover, the solution fits in with modern agricultural manufacturing in accordance with the ideas of precision agriculture.

Design and performance analysis of a passive rotatable deflector diversion tail for tidal current power generation hydrokinetic turbines

In the present study, a deflector that can passively rotate is designed for use on a hydrokinetic turbine that generates power from tidal currents. This deflector is capable of self-adjusting its position with changes in the water flow, so that the hydrokinetic turbine can generate maximum power at both high and low tides. The purpose of this study is to maximize the output power of a hydrokinetic turbine by improving the geometry of the deflector and the diversion tail. The rotation of both the turbine and the deflector are simulated with finite element analysis software. In addition, the accuracy of the simulation results is verified through experimental tests. The improved design of the deflector and the diversion tail is considered in terms of the parameters, including the deflector reduction angle, the gap between the deflector and the turbine, and the height of the diversion tail. The geometrical design of the deflector and the diversion tail is compared to a turbine without the deflector and to another turbine with the original deflector over the entire operating range using CFD simulations. Without the deflector, the maximum power coefficient of the turbine was 0.0979 at a tip-speed ratio of 0.4, whereas the maximum power coefficient of the turbine was 0.306 at a tip speed ratio of 0.57 when using the improved deflector. The results indicate that, after adding the improved deflector, the power coefficient of the turbine was 3.13 times greater compared with the turbine without the deflector and 18% greater compared with the turbine equipped with the original deflector.

Experimental investigation and structural optimization prediction of a novel carbon stripper for solid-fuel chemical looping combustion

The addition of carbon stripper (CS) can effectively improve the carbon conversion efficiency in the fuel reactor of solid-fuel chemical looping combustion system. An independent CS system is constructed, and the feasibility of the system is verified through feasibility tests and reference work condition tests. The effects of important conditions on the separation performance of CS are also explored based on the experimental platform. It is found that increasing the main gas velocity and cross-flow velocity in the air reactor can effectively improve the directional separation efficiency of binary particles. On the other hand, based on the Computational Fluid Dynamics platform, the important structural factors, including baffle angle, deflector angle and deflector length of the CS, are studied for the directional separation mechanism of binary particles. The results show that a CS structure with the baffle length of 140 mm, the baffle angle of 110°, the deflector length of 40 mm, and the deflector angle of 60° exhibits good directional separation performance. In this case, the separation efficiency of quartz sand is close to 100%, and that of polyvinyl chloride (PVC) particles can reach a high value of 93.7%, demonstrating the high separation efficiency and promising application prospects of this novel CS.

Effect of structural parameters on the hydrodynamic performance of vertical curved V-Type otter board

In order to study the influence mechanism of structural type and size on the hydrodynamic performance of vertical curved V-type otter board, this paper based on the computational fluid dynamics method, a three-dimensional numerical model of vertical curved V-type otter board is established to calculate and analyze its hydrodynamic performance, and the validity of the numerical simulation results is verified by designing and constructing a scaled model for dynamic flume experiments. On this basis, the effects of different structural parameters, such as the deflector angle, camber, and spacing, on the hydrodynamic performance of the vertical curved V-Type otter board are investigated and the optimal structural design scheme is determined. The results demonstrate that single or synchronous changes of the angle, camber, and spacing of the two deflectors have varying degrees of impact on the hydrodynamic performance of the vertical curved V-Type otter board. To improve the expansion effect of the otter board, setting the angle of the deflector A to 40° and that of the deflector B to 30°, or setting the camber of deflectors A and B to 18%, or setting the spacing between deflectors A and B to 380 mm and that between the deflector and the main panel to 670 mm can increase the lift coefficient of the vertical curved V-Type otter board to its maximum value. Considering the overall performance of the otter board, when the angle of the deflector A is set to 25° and that of the deflector B is set to 30°, or the camber of the deflector A is set to 6% and that of the deflector B is set to 9%, or the spacing between deflectors A and B is set to 340 mm and that between the deflector and the main panel is set to 610 mm, the lift-to-drag ratio of the otter board can be increased to its maximum value.

Soybean crushing forms by mechanical harvesting and factors affecting the proportions of different forms

Aiming at the problem of serious damage in the process of soybean harvesting and production, this paper analyzes the soybean harvesting process, and determines the main crushing forms of soybeans: epidermal breakage, splitting into two flaps, and overall crushing. The influence of different operation links on soybean crushing during the harvesting process, such as header feeding auger, horizontal seed spiral conveyor, horizontal miscellaneous residue spiral conveyor, and threshing roller was studied. The influence of the operating parameters such as the forward speed of the harvester, threshing roller speed, and deflector angle on the soybean crushing form was studied experimentally. The results showed that, the degree of influence on the proportion of sepidermal breakage from high to low was the forward speed of the harvester, deflector angle and threshing roller speed. The degree of influence on the proportion of splitting into two flaps from high to low was the deflector angle, threshing roller speed and the forward speed of the harvester. The degree of influence on the proportion of the overall crushing from high to low was the forward speed of the harvester, threshing roller speed and deflector angle.The research results can provide a reference for the subsequent structural improvement of soybean harvester and optimization of operating parameters.

Performance evaluation of an architecturally-designed vertical high capacity linear slot diffuser in a tropical atrium

This paper proposed a new approach for the efficient air conditioning of large tropical buildings. The current study has two objectives: the design and numerical investigations of the performance of vertically oriented high capacity linear slot diffusers (HCLSD) in an atrium building and the verification and validation of the different turbulence models through laboratory-scale experiments. The HCLSD was investigated with varying angles of inclination of the blades (ϕ = 0o to 25o) for the in-depth performance analyses. The performance was evaluated by monitoring and comparing the velocity and temperature profiles along the vertical lines drawn at different locations in the studied domain. A relatively longer jet throw was noticed through quantitative analysis at ϕ = 0o. Note that more than 33% increment in the face velocity was recorded at this angle. The corresponding terminal velocity of 0.225 m/s was observed at 8 m distance from the diffuser face. The detailed investigations at 0o deflector angle (case-1) were carried out for velocity, temperature field, and thermal comfort indices, i.e. PMV and PPD models. For the occupied zone, the thermal comfort indices were found within the acceptable ranges (i.e. PMV = + 0.1 to +0.9 and PPD = 4% to 20%). Abbreviations: ACMV: Air conditioning and mechanical ventilation; CFD: Computational fluid dynamics; CMH: Cubic meter per hour; DV: Displacement ventilation; HCLSD: High capacity linear slot diffuser; IAQ: Indoor air quality; MV: Mixing ventilation; PMV: Predicted mean vote; PPD: Predicted percentage dissatisfied; RANS: Reynolds-Averaged Navier – Stokes; RNG: Re-Normalization Group; SST: Shear-Stress Transport: SIMPLE: Semi-implicit method for pressure linked equations; VAV: Variable air volume; VSD: Variable speed drives

Effect of deflector angle and number on evaporation performance of desulfurization wastewater in a spray drying tower

Rotary spray drying technology with bypass flue is widely adopted to realize the zero-discharge of desulfurization wastewater in coal-fired power stations. Significantly, the deflector structure of the drying tower is an essential factor affecting the evaporation performance of desulfurization wastewater. This paper is aimed to study the effect of the angle and number of the deflectors on the evaporation performance in a drying tower of a 600 MW coal-fired station. Results show that the gas distributor divides the flue gas into internal and external parts, and the flue gas in the internal channel is the main factor affecting the evaporation performance. The deflector angles (especially for the internal deflector) have a remarkable impact on the evaporation behaviors, while the deflector numbers just have a minor effect on that. When the deflector number is 24 and the angles of internal and external deflectors are set at 0° and 45°, respectively, a better evaporation performance is obtained with the weighted average time of approximately 0.17 s and the complete evaporation distance of approximately 3.93 m. These optimal settings are adopted in the actual operation, and the industrial measured results show good performance is obtained.

纵轴流玉米柔性脱粒装置设计与试验研究

In order to reduce the problems of high grain breakage rate and uncleaned material rate in the threshing and separating device of longitudinal axial flow corn, a threshing device of "front flexible nail tooth + rear pressure spring elastic short grain rod" was designed and the threshing elements were arranged spirally on the conical threshing drum. Discrete element method and field test were used to verify the feasibility of threshing drum design, and EDEM simulation software was used to obtain the appropriate guide plate Angle parameter range. Single factor test was carried out on each experimental factor under high and low water content conditions, and four factors suitable working range was obtained.On this basis, four factors and three levels orthogonal test were carried out on grain breakage rate and undepurated rate, rotational speed of roller, feeding rate, cylinder-concave clearance and deflector angle as experimental factors. Range and variance analysis were used to analyze the rotational speed of roller, feeding rate, cylinder-concave clearance and deflector angle. The results showed that:Under the conditions of low water content, the threshing effect is the best under the conditions of feeding rate of 8kg/s,rotational speed of roller of 450 r/min, cylinder-concave clearance of 45 mm, and deflector angle of 70°.Under the conditions of high water content,the best threshing effect was achieved under the conditions of feeding rate of 7kg/s, rotational speed of roller of 450 r/min, cylinder-concave clearance of 40 mm and deflector angle of 75°. Compared with the conventional threshing separation device, the grain breakage rate of low moisture content decreased by 39.4% and the uncleaned material rate decreased by 63.9%.The grain breakage rate of high moisture content was reduced by 45.5%, and the uncleaned material rate was reduced by 66.7%, which was better than the conventional longitudinal axial flow threshing separation device. The research results can provide reference for the design and optimization of longitudinal axial flow corn harvester.

Experimental investigation on the effects of deflector angles on the power performance of a Savonius turbine for hydrokinetic applications in small rivers

A vertical-axis drag-driven Savonius turbine has various advantages and has demonstrated strong potential in hydrokinetic applications for sustainable rural electrification. However, its applicability is limited by the low coefficient of power inherent in the system. To solve this issue, the present study aims to evaluate the power performance improvement of a conventional Savonius turbine using two deflectors on the advancing and returning blades. Wind tunnel experiments conducted at Reynolds number, Re = 148,000 corresponding to 7.0 m/s (equivalent to 0.4 m/s water flow speed for hydrokinetic applications) revealed that, among the 30 deflector angle configurations tested, the advancing and returning blade deflectors were optimally configured at 30° and 90°, respectively. This combination of deflector angles resulted in the highest maximum coefficient of power at CPmax= 0.21, a 61.53% improvement relative to the case without the deflectors. This optimal configuration deflected the flow to the advancing blade while blocking the flow from impinging on the returning blade, effectively increasing the net positive torque and consequently the power performance. Moreover, it was found that variations in the returning blade deflector angle, δR had more significant effects on the turbine power than variations in the advancing blade deflector angle, δA. Conclusively, careful optimization of the deflector angle configurations was able to increase turbine power performance, suitable for practical implementation in small rivers with low flow rates for optimal power production.

Characteristics analysis and parameters optimization of desulfurization wastewater evaporation in a rotary spray drying tower

Recently, the rotary spray drying technology has received significant attention by virtue of its excellent performance in zero liquid discharge (ZLD) of desulfurization wastewater. Based on the Euler-Lagrangian numerical method of gas-liquid coupling, the gas multi-physical distribution is studied. Meanwhile, the relationship between the evaporation and dispersion characteristics of wastewater and various parameters such as deflector angle, deflector number, hot air distributor outlet radius difference, atomizer rotational speed and rotational direction is investigated. Numerical results show that the spray droplets can strengthen the vortex of the flue gas, thus increasing the evaporation rate. By increasing the deflector angle and the radius difference, droplets were observed to be more dispersed, which leads to improve evaporation efficiency on one hand but enhance the trend of droplets adhering to the wall on the other hand. The optimum deflector angle and radius difference are found to be 15° and 74 mm, respectively. The deflector number has little effect on the evaporation efficiency of droplets. It can be found that the evaporation time of droplets decreases with the increase of rotational speed, and the effect of the reverse rotation is more obvious. Under the case of reverse rotation at 20,100 rpm, the mean evaporation time is reduced to 0.2 s, and no droplets hit the wall.

Performance and Design of a Stepped Spillway Aerator

Stepped spillways are frequently limited to specific discharges under around 30 m2/s due to concerns about potential cavitation damages. A small air concentration can prevent such damages and the design of bottom aerators is well established for smooth chutes. The purpose of this study is to systematically investigate the performance of a deflector aerator at the beginning of stepped chutes. Six parameters (chute angle, step height, approach flow depth, approach flow Froude number, deflector angle and deflector height) are varied in a physical model. The spatial air concentration distribution downstream of the aerator, the cavity sub-pressure, water discharge and air discharges are measured. The results describe the commonly used air entrainment coefficient, the jet length, as well as the average and bottom air concentration development to design an aerator. The lowest bottom air concentration measured in all tests is higher than the air concentration recommended in literature to protect against cavitation damages. And, unlike smooth chutes, there appears to be no significant air detrainment downstream of the jet impact. One deflector aerator seems therefore sufficient to provide protection of a stepped spillway.

A new structure optimization method for forced air-cooling system based on the simplified multi-physics model

Energy storage systems equipped with lithium-ion batteries are susceptible to fire and explosion hazards, especially when such batteries are used to power electric vehicles. One of the most important reasons for these undesirable consequences is the lack of an effective battery thermal management system. In this regard, an optimization method for the forced air-cooling system is introduced based on a simplified multi-physics simulation model. The simplified multi-physics model consists an electro-thermal coupling model and a flow resistance network model. The accuracy of the simplified multi-physics model is verified by comparison with experimental results. Subsequently, the deflector angle and cell space in the forced air-cooling system are optimized, respectively, based on the simplified multi-physics model, via an exhaustive search method and a genetic algorithm. Finally, the verification platform for the forced air-cooling system is built. After the optimization of deflector angle and cell space, the maximum temperature and temperature difference are limited to 38℃ and 2℃, with a reduction of about 30% and 80%, with respect to the unoptimized version. The consistency between the simulated and measured maximum temperature further confirms the effectiveness of the structure optimization method. In that, the method proposed in this paper is of great significance to shorten the time of structural optimization for forced air-cooling systems.

Effects of the deflector plate on performance and flow characteristics of a drag-type hydrokinetic rotor

An experimental work was conducted to investigate effects of the deflector plate on the performance and flow characteristics of a drag-type hydrokinetic rotor. A measurement device was specifically designed to record instantaneous rotational speed and output torque of the hydrokinetic rotor. The performance of the rotor and the near-rotor flow were studied comprehensively. The deflector angle and the upstream velocity were varied. The results show that the maximum power coefficient of the rotor reaches 0.463 at the deflector angle of 60°, approximately 2.5 times that obtained at the deflector angle of 30°. As the upstream water velocity increases from 0.63 m/s to 0.73 m/s, the maximum power coefficient of the rotor is increased by 22.8%. The deflector plate not only prevents the impingement of the upstream flow on the returning blade, but also guides the upstream flow toward the concave side of the advancing blade. As the deflector angle increases, more upstream water with high velocity is guided toward the concave side of the advancing blade. The Coanda-like flow arising at the convex side of the advancing blade is beneficial for the improvement of the rotor performance and is enhanced with increasing deflector angle. The effect of the deflector plate on the operation of the Savonius hydrokinetic rotor was clarified and the conclusions provide a sound support for the improvement of the rotor performance.

Effect of Deflectors on the Flow Characteristics of a Square Pipe with a 90° Bend

Pipe flow is a classic hydrodynamic issue. Most pipelines contain bends, and bends cause energy loss and distort the flow because of secondary flow. Deflectors are often used to adjust the flow quality in a bend. In this study, a numerical simulation using ANSYS Fluent 19.0 is used to analyze the effects of the deflector number, location and angle on the flow characteristics of a square pipe with a 90° bend. The velocity non-uniformity and the head loss are analyzed quantitatively. The secondary flow is presented visually, and its evolution characteristics are assessed. An optimized installation scheme for the deflectors is discussed, and a reference is provided for controlling the flow quality in bends via deflectors.

Design and development of paddy straw bale shredder

A tractor operated paddy straw bale shredder cum mulcher was designed and developed at Punjab Agricultural University, Ludhiana during 2018-19 to use baled paddy straw as mulch. Mulching reduces weed emergence, increases available water capacity and improves soil properties that results in yield increment. Paddy straw size is generally more than row to row and plant to plant spacing of vegetable crops. Its size was reduced using developed machine. Theoretical design of the machine was followed by development of 3D model and fabrication. The developed machine comprised a shredding rotor for shredding paddy straw bales, a bale drum to handle the bales, a concave grate to control the feeding of bales, a deflector unit for uniform spreading of shredded paddy straw bales and power transmission unit. It has overall dimensions of 1800×1300×1400 mm. The developed machine was run in lab to select operational parameters of the machine. It was further evaluated for mat thickness and uniformity of spread. Effect of forward speed and rotor speed was significant on mat thickness as well as uniformity of spread at 5% level of significance. However, effect of deflector angle on both dependent parameters was non-significant. Mat thickness decreased with increase in forward speed and decrease in rotor speed. Its maximum value was 64 mm for forward speed of 2.7 km/h, rotor speed of 30.7 m/s and deflector angle of 25°. Uniformity of spread was determined using coefficient of variation and its minimum value was 34.38% for forward speed of 2.7 km/h, rotor speed of 30.7 m/s and deflector angle of 25°.