• 제목/요약/키워드: Spray Control

Search Result 835, Processing Time 0.023 seconds

Effect of Foliar Spray upon Mulberry Damaged by Late Frost (늦서리 피해 뽕나무의 엽면시비 효과)

  • 김종한;김동일
    • Journal of Sericultural and Entomological Science
    • /
    • v.32 no.2
    • /
    • pp.89-93
    • /
    • 1990
  • Mulberry, damaged by a late frost on April 27, received a foliar spray of 0.5% Urea or Jambi(a foliar fertilizer). The sprays were applied once every 3 days from May 16 for 12 days. The results were : 1. Approximately 70 auxillary buds per tree sprouted after the frost. The difference between the lowest and highest number of buds was 3 to fold. 2. For the 25 days beginning May 18, shoot length increased 5.4 fold, leaf number 2.1 fold, and shoot weight 9.6 fold. 3. Yield from latent buds was about 5% of total yield. 4. Length of new shoots decreased 26% due to frost. Urea spray and Jambi increased shoot length 10% and 1%, respectively, compared to control. 5. Leaf number decreased by 5.2 due to frost. Urea spray and Jambi increased leaf number 18% and 5%, respectively, compared to control. 6. Weight of new shoot was decrease 43% by frost. Urea and Jambi spray increased shoot weight 7% and 6%, respectively, compared to control. 7. Net leaf yield decreased 47% due to frost. Urea spray and Jambi increased left yield 7% and 5%, respectively, compared to control. 8. Yield in an undamaged plot was 1,587kg, damaged 932kg, 1,070kg in urea spray, and 1,033kg/10a in Jambi spray. Yield of frost damaged plots was 59% of undamaged. Foliar spray increased this to 68% of undamaged. 9. Yield increased 3.5% daily by with postponement of harvest. Yield of four days postponement was expected 73% of undamaged. Urea spray with 4 days postponement expected to be increased this to 82% of undamaged.

  • PDF

A study on the spray characteristics of CRDI system with injection pressure (분사압력에 따른 CRDI 분사계의 분무특성에 관한 연구)

  • KIM, Sang-Am;WANG, Woo-Gyeong;YANG, Jung-Kyu
    • Journal of the Korean Society of Fisheries and Ocean Technology
    • /
    • v.52 no.1
    • /
    • pp.65-71
    • /
    • 2016
  • Injection rate, injection quantity and injection timing of fuel are controlled precisely by electric control in CRDI system. Particularly, injection rate being influenced with injection pressure affects to spray characteristics and fuel-air ratio, so it is a very important factor in diesel combustion. In this study, injection rates in accordance with injection pressure at a constant ambient pressure were measured with Zeuch's method. Under the same condition, non-evaporating spray images were taken with a high speed camera and analyzed carefully with Adobe Photoshop CS3. Macroscopic spray characteristics and breakup processes in the spray could be found from the examined and analyzed data. Injection start time and injection period were practically affected with injection pressure. Also, initial injection rate, spray penetration, spray angle and breakup of high density droplets region in the spray were affected with injection pressure. The results and techniques of spray visualization and injection rate measurement in this study would be practically effective to study a high pressure diesel spray for common rail direct injection system.

Steady-Flow Characteristics and Its Influence on Spray for Direct Injection Diesel Engine

  • Jeon, Chung-hwan;Park, Seung-hwan;Chang, Young-june
    • Journal of Mechanical Science and Technology
    • /
    • v.16 no.7
    • /
    • pp.986-998
    • /
    • 2002
  • Flow and spray characteristics are critical factors that affect the performance and exhaust emissions of a direct injection diesel engine. It is well known that the swirl control system is one of the useful ways to improve the fuel consumption and emission reduction rate in a diesel engine. However, until now there have only been a few studies on the effect of flow on spray. Because of this, the relationship between the flow pattern in the cylinder and its influence on the behavior of the spray is in need of investigation. First, in-cylinder flow distributions for 4-valve cylinder head of DI (Direct Injection) Diesel engine were investigated under steady-state conditions for different SCV (Swirl Control Valve) opening angles using a steady flow rig and 2-D LDV (Laser Doppler Velocimetry). It was found that swirl flow was more dominant than that of tumble in the experimented engine. In addition, the in-cylinder flow was quantified in terms of swirl/tumble ratio and mean flow coefficient. As the SCV opening angle was increased, high swirl ratios more than 3.0 were obtained in the case of SCV -70° and 90°. Second, spray characteristics of the intermittent injection were investigated by a PDA (Phase Doppler Anemometer) system. A Time Dividing Method (TDM) was used to analyze the microscopic spray characteristics. It was found that the atomization characteristics such as velocity and SMD (Sauter Mean Diameter) of the spray were affected by the in-cylinder swirl ratio. As a result, it was concluded that the swirl ratio improves atomization characteristics uniformly.

A Study for Characteristics of Geofiber Reinforced Soil System Practiced on Stone Gabion Bank of River (하천 돌망태 호안에 적용된 토목섬유보강토공법의 녹화 특성)

  • Jeong, Dae-Young;Kim, Jae-Hwan;Shim, Sang-Ryul
    • Journal of the Korean Society of Environmental Restoration Technology
    • /
    • v.11 no.6
    • /
    • pp.81-90
    • /
    • 2008
  • Recently, geofiber(polyester) reinforced soil was added on soil-seed mixture spray to control erosion and to improve vegetation growth on rocky slope sites. This research was conducted to compare vegetation effects and soil hardness on three types of soil-seed mixture spray on stone gabion river bank [A type : soil-seed mixture spray underlying 30cm thick sand with geofiber(geofiber reinforced soil system), B type : soil-seed mixture spray underlying 30cm thick sand without geofiber, C type : soil-seed mixture spray]. Evaluation were made concerning vegetation coverage, soil hardness and moisture content. The results of this study showed that A type system was effective for the growth of vegetation and soil hardness when compareed to B type and C type. A type and B type showed higher covering rate than C type on stone gabion river bank, and especially A type showed the highest covering rate. Soil hardness and water content were high on A type vegetation system compared to B type and C type. We noted that high soil hardness and high moisture content with geofiber(geofiber reinforced soil system) were effective both to control erosion from water current impact and to be high coverage and species of vegetation on stone gabion river bank.

Effects of Method, Number of Times for Spraying and! Ventilation Condition on the Growth in Greenhouse (관수방법, 관수회수 및 송풍처리에 따른 초화류의 생장에 미치는 영향)

  • 민병로;김웅;이범선;이대원
    • Journal of Bio-Environment Control
    • /
    • v.13 no.3
    • /
    • pp.149-155
    • /
    • 2004
  • On this study, a multipurpose operating system was developed to adjust a configuration of a moving path which have no connection with a form of greenhouse. To being performance the multipurpose working system, we have experienced growth quality on the plants in greenhouse. Some of the results are as follows. While watering by the hand spray. the condition of plant was generally no good. It was shown that plant height and leaf area were all high without wind during watering by the automatic spray. The effect to retrain a plant growth was high as a ventilation was strong. The diameter of a plant stem was small without ventilation condition during watering 3 times by automatic spray. The number of leaf was relatively large during 3 times by automatic spray compared to 2 times by automatic spray or hand spray. Growth of plant was fast as the times of spray were large.

Effects of Needle Response on Spray Characteristics In High Pressure Injector Driven by Piezo Actuator for Common-Rail Injection System

  • Lee Jin Wook;Min Kyoung Doug
    • Journal of Mechanical Science and Technology
    • /
    • v.19 no.5
    • /
    • pp.1194-1205
    • /
    • 2005
  • The common-rail injection systems, as a new diesel injection system for passenger car, have more degrees of freedom in controlling both the injection timing and injection rate with the high pressure. In this study, a piezo-driven injector was applied to a high pressure common-rail type fuel injection system for the control capability of the high pressure injector's needle and firstly examined the piezo-electric characteristics of a piezo-driven injector. Also in order to analyze the effect of injector's needle response driven by different driving method on the injection, we investigated the diesel spray characteristics in a constant volume chamber pressurized by nitrogen gas for two injectors, a solenoid-driven injector and a piezo-driven injector, both equipped with the same injection nozzle with sac type and 5-injection hole. The experimental method for spray visualization was based on back-light photography technique by utilizing a high speed framing camera. The macroscopic spray propagation was geometrically measured and characterized in term of the spray tip penetration, spray cone angle and spray tip speed. For the evaluation of the needle response of the above two injectors, we indirectly estimated the needle's behavior with an accelerometer and injection rate measurement employing Bosch's method was conducted. The experimental results show that the spray tip penetrations of piezo­driven injector were longer, on the whole, than that of the solenoid-driven injector. Besides we found that the piezo-driven injector have a higher injection flow rate by a fast needle response and it was possible to control the injection rate slope in piezo-driven injector by altering the induced current.

An Advanced Method for Behavior-Characteristics Analysis of Diesel Fuel Spray

  • Yeom, Jeong-Kuk
    • Journal of Power System Engineering
    • /
    • v.18 no.3
    • /
    • pp.5-13
    • /
    • 2014
  • In order to control emissions from engine, it is necessary to understand the mixture formation process of diesel spray. In this study, analysis of diesel fuel(n-Tridecane, $C_{13}H_{28}$) spray under a high temperature and pressure was performed by a general-purpose program, ANSYS CFX release 11.0, and the results of these are compared with experimental results of diesel fuel spray using the Exciplex Fluorescence Method. The simulation results of diesel spray is analyzed by using the combination of Large-Eddy Simulation(LES) and Lagrangian Particle Tracking(LPT), and then injection pressure was selected as an analysis parameter. Consequently, it was found that the experimental results and the numerical results are consistent with each other, and then in order to investigate the behavior characteristics of evaporative diesel spray, the effectiveness of the use of CFX of commercial code is definitely validated.

Parametric Analysis of Digital Particle Holography for Spray Droplets (분무 액적을 위한 디지털 입자 홀로그래피의 파라미터 해석)

  • Yang, Yan;Kang, Bo-Seon
    • Journal of ILASS-Korea
    • /
    • v.12 no.4
    • /
    • pp.191-197
    • /
    • 2007
  • This study presents in-line digital particle holography and its application to spray droplets to measure the characteristics of spray droplets. Several important parameters at the time of hologram recording such as the object distance and the region of laser beam used were verified. The correlation coefficient method with important parameters such as the reconstruction interval and the correlation interval was used for determination of the focal planes of particles. The optimal values of all these parameters are obtained by either numerical simulation of holograms or experiments. Using these optimal parameters, double pulse digital spray holograms in a short time interval were recorded with the synchronization system for the time control. The spatial positions of droplets that are used for the evaluation of the three dimensional droplet velocities can be easily located, which proves the feasibility of the digital holographic technology for measurements of several important features of spray droplets.

  • PDF

Recent Developments in Agricultural Sprays : Review

  • No, S. Y.
    • Agricultural and Biosystems Engineering
    • /
    • v.3 no.1
    • /
    • pp.44-54
    • /
    • 2002
  • A brief review of current status in the field of agricultural spray and future research challenges are presented. Researches on the pesticides sprays, pollen sprays, postharvest sprays, and biological control agent sprays among the various applications of agricultural spray were selected and reviewed. In the agrochemical sprays, the techniques to increase the deposition such as electrospray and reduce the drift such as introductions of drift retardants and of mechanical means are reviewed. The introduction of mechanical means includes low drift, air-assisted, air inclusion, shield or shroud assisted and pulse flow nozzles. For flat fan nozzles, the data of breakup length and thickness of liquid sheet are essential to understand the atomization processes and develop the transport model to target In the air-assisted spray technology to reduce drift, further works on the effect of application height on drift and air assistance on droplet size should be followed. In addition, methods for quantifying the included air in the air inclusion techniques are required. The atomization characteristics of biopesticides spray are not being elucidated and the formulations of biopesticides should be taken into account the spray characteristics of existing nozzle and sprayer. A few researches on the droplet size of fallout can be found in the literature. A combined technology with electrostatic method into one of method for the reduction of drift may be an effective strategy for increasing deposition and reducing drift. Only an integrated approach involving all stakeholders such as engineers, chemists, and biologists, etc. can result in improved application of agricultural spray.

  • PDF

An Experimental Study on Diesel Spray Dynamics and Auto-Ignition Characteristics to use Rapid Comperssion Machine (RCM을 이용한 디젤 분무 거동 및 자발화 특성에 관한 실험적 연구)

  • Ahn, J.H.;Kim, H.M.;Shin, M.C.;Kim, S.W.
    • Journal of ILASS-Korea
    • /
    • v.8 no.3
    • /
    • pp.33-40
    • /
    • 2003
  • The low-emission and high-performance diesel combustion is an important issue in the combustion research community, In order to understand the detailed diesel flame involving the complex physical processes, it is quite desirable to diesel spray dynamics, auto-ignition and spray flame propagation. Dynamics of fuel spray is a crucial element for air-fuel mixture formation, flame stabilization and pollutant formation, In the present study, the diesel RCM (Rapid Compression Machine) and the Electric Control injection system have been designed and developed to investigate the effects of injection pressure, injection timing, and intake air temperature on spray dynamics and diesel combustion processes, In terms of the macroscopic spray combustion characteristics, it is observed that the fuel jet atomization and the droplet breakup processes become much faster by increasing the injection pressure and the spray angle, With increasing the cylinder pressure, there is a tendency that the of spray pattern in the downstream region tends to be spherical due to the increase of air density and the corresponding drag force, Effects of intake temperature and injection pressure on auto-ignition is experimently analysed and discussed in detail.

  • PDF