• Title/Summary/Keyword: flow control device

Search Result 408, Processing Time 0.292 seconds

A Study on the Auto Fuel Feeding Control System using Hall Sensor (홀 센서를 이용한 자동연료공급 제어장치에 관한 연구)

  • Kim, Gyu-Sung;Cho, Myung-Hyun
    • 전자공학회논문지 IE
    • /
    • v.43 no.3
    • /
    • pp.34-40
    • /
    • 2006
  • Usually, fluid or fuel supply device need space to need special sensor to control motor, attaches with ancillary equipment to attach sensor. Also, difficult point follows need signal line and other circuit etc. In this paper, used that proposed control system that use hall sensor to solve discomfort and problem and difference control principle of system happens in current flow according to motor action step. Also, could reduce breakdown by sensor establishment, reduce material costs and personnel expenses as well as control system superior. Auto-pumping system sees that will can apply, develop several kind of device that use system hereafter to all fluid supply systems through soft-ware adaptation.

Sectional Flow-rate Control of Boom Sprayer According to the Steering Radius along Winding Rows (붐방제기의 곡선행로 조향반경에 따른 붐의 구간별 유량제어)

  • Kim E.S.;Kim Y.J.;Rhee J.Y.
    • Journal of Biosystems Engineering
    • /
    • v.31 no.3 s.116
    • /
    • pp.146-152
    • /
    • 2006
  • Most upland in Korea have irregular field shapes. Boom sprayers working alone winding row will show considerable differences of spraying amount per unit area between left and right booms. If flow rates of both booms are equal. This phenomenon becomes significant as steering radius of sprayer decreases. This study was performed to seek a method which reduce the difference of the spray amount between left, right and center booms while spraying along curvy rows. A flow rate control method for keeping application rate of each boom section constant was proposed and experimentally proved using a boom sprayer attached to a cultivating tractor. The flow rate control device was composed of 3 ball valves and a rotary angle sensor. The rotary angle sensor showed a symmetric voltage output with respect to steering radius. The spray overlapping was happened in a boom nearby the steering center when steering radius of the sprayer was less than 5.2 m. Flow rates for left, right and center booms were regulated using ball valves based on the steering radius and spraying areas ration of right/left boom. The Maximum spraying area ratio ($S_{LR}$) of left to right boom section was 1:3.6 at the steering radius of 5.2 m. However, The Maximum achieved right and left spraying flow ratio was 1:2.7.

Effect of trailing-edge modification over aerodynamic characteristics of NACA 0020 airfoil

  • Ethiraj, Livya;Pillai, Subramania Nadaraja
    • Wind and Structures
    • /
    • v.33 no.6
    • /
    • pp.463-470
    • /
    • 2021
  • This study investigates the aerodynamic characteristics of NACA series airfoil by altering the trailing edge in the form of extended and serrated sections. This contemporary advent examined NACA 0020 airfoil experimentally at the angle of attack ranging from 0° to 45° and for the Reynolds number of 2.46 × 105. To figure out the flow behaviour, the standard average pressure distribution over the airfoil surface is estimated with 50 pressure taps. The time series surface pressure is recorded for 700 Hz of sampling frequency. The extended trailing edge of 0.1 c, 0.2 c and 0.3 c are attached to the base airfoil. Further, the triangular serration is introduced with the base length of 2 cm, 4 cm and 6 cm. Each base length with three different amplitudes of 0.1 c, 0.2 c and 0.3 c were designed and equipped with the baseline case at the trailing edge and tested. The aerodynamic force coefficient, as well as pressure coefficient are presented. The obtained data advises that modification in the trailing edge will reflect the aerodynamic characteristics and the flow behaviour over the section of a wing. Resultantly, the extended trailing edge as a thin elongated surface attached to a base airfoil without revising the main airfoil favors good lift increment. The serrated trailing edge acts as a flow control device by altering the flow pattern results to delay the stall phenomenon. Besides it, improves lift co-efficient with less amount of additional drag. This extended and serrated trailing edge approach can support for designing the future smart airfoil.

CFD Analysis of Marine Propeller-Hub Vortex Control Device Interaction (프로펠러와 허브 보오텍스 조절장치 상호작용 CFD 해석)

  • Park, Hyun-Jung;Kim, Ki-Sup;Suh, Sung_Bu;Park, Ill-Ryong
    • Journal of the Society of Naval Architects of Korea
    • /
    • v.53 no.4
    • /
    • pp.266-274
    • /
    • 2016
  • Many researchers have been trying to improve the propulsion efficiency of a propeller. In this study, the numerical analysis is carried out for the POW(Propeller Open Water test) performance of a propeller equipped with an energy saving device called PHVC(Propeller Hub Vortex Control). PHVC is aimed to control the propeller hub vortex behind the propeller so that the rotational kinetic energy loss can be reduced. The unsteady Reynolds Averaged Navier-Stokes(URANS) equations are assumed as the governing flow equations and are solved by using a commercial CFD(Computational Fluid Dynamics) software, where SST k-ω model is selected for turbulence closure. The computed characteristic values, thrust, torque and propulsion efficiency coefficients for the target propeller with and without PHVC and the local flows in the propeller wake region are validated by the model test results of KRISO LCT(Large Cavitation Tunnel). It is concluded from the present numerical results that CFD can be a good promising method in the assessment of the hydrodynamic performance of PHVC in the design stage.

Design of Test Device for Quantitative Observation of Performances of Thrust-Vectoring Nozzle (추력편향 노즐의 정량적 성능특성 관찰을 위한 시험장치 설계)

  • Song, Myung-Jun;Yoon, Sang-Hun;Cho, Yong-Ho;Lee, Yeol
    • Proceedings of the Korean Society of Propulsion Engineers Conference
    • /
    • 2011.11a
    • /
    • pp.404-407
    • /
    • 2011
  • The fluidic thrust vector control using co-flowing coanda effect of secondary jet at the nozzle exit is a new concept for efficient thrust vectoring of supersonic jet exhausts. Flow visualization of the flow fields in previous studies have shown some pros and cons of the technique, however, most of the observations were somewhat limited as qualitative data. The present study was designed to evaluate the quantitative performance-characteristics of the thrust-vectoring technique utilizing coanda effects of the secondary jet. Details of design of the test device and calibration/data reduction procedure are provided.

  • PDF

Energetics of the Heart Model with the Ventricu1ar Assist Device

  • Chung, Chanil-Chung;Lee, Sang-Woo;Han, Dong-Chul;Min, Byoung-Goo
    • Journal of Biomedical Engineering Research
    • /
    • v.17 no.1
    • /
    • pp.43-48
    • /
    • 1996
  • We investigated the energistics of the physiological heart model by comparing predictive indexes of the myocardial oxygen consumption (MOC), such as tension-time index (R), tension-time or force-time inteual (FTI), rate-pressure product (RPP), pressure-work index, and systolic pressure-volume area (PVA) when using the electro-hydraulic left ventricular device (LVAD). We developed the model of LVAD incorporated the closed-loop cardiovascular system with a baroreceptor which can control heart rate and time-varying elastance of left and right ventricles. On considering the benefit of the LVAD, the effects of various operation modes, especially timing of assistance, were evaluated using this coupled computer model. Overall results of the computer simulation shows that our LVAD can unload the ischemic (less contractile) heart by decreasing the MU and increasing coronary flow. Because the pump ejection at the end diastolic phase of the natural heart may increase the afterload of the left ventricle, the control scheme of our LVAD must prohibit ejecting at this time. Since the increment of coronary flow is proportional to the peak aortic pressure after ventricle contraction, the LVAD must eject immediately following the closure of the aortic valve to increase oxygen availability.

  • PDF

Voltage Stability Enhancement by Optimal Placement of UPFC

  • Kowsalya, M.;Ray, K.K.;Shipurkar, Udai;Saranathan
    • Journal of Electrical Engineering and Technology
    • /
    • v.4 no.3
    • /
    • pp.310-314
    • /
    • 2009
  • This paper presents the improvement of the voltage profiles of power system networks by the inclusion of Unified Power Flow Controller (UPFC). The mathematical model of the UPFC is incorporated in the load flow algorithm and the L-index is calculated for the different values of the control parameter r $and{\gamma}$. The positioning of the UPFC device is changed to minimize the sum of the squares of the L-indices at all load buses. The test cases considered for the improvement of voltage profile with the WSCC 9-bus and IEEE 30 bus system. With the best position of UPFC along with the control parameters the improvement in voltage profile of the power system networks are obtained. The results obtained are quite encouraging compared with other techniques used to identify the best location of UPFC.

NUMERICAL STUDY ON THE MIXER TYPE OF UREA-SCR SYSTEM FOR FLOW MIXING IMPROVEMENT (Urea-SCR 시스템의 유동혼합 개선을 위한 혼합기 형상에 관한 수치적 연구)

  • Lee, J.W.;Choi, H.K.;Yoo, G.J.;Kim, W.S.
    • 한국전산유체공학회:학술대회논문집
    • /
    • 2010.05a
    • /
    • pp.368-375
    • /
    • 2010
  • To alleviate NOx emission, a variety of approaches has been applied. In marine diesels, the application of SCR systems has been considered an effective exhaust aftertreatment method for NOx emission control. Most current SCR systems use a various catalyst for the reaction of ammonia with NOx to form nitrogen and water. In theory, it is possible to achieve 100% NOx if the NH3-to-NOx ratio is 1:1. However, the reaction has a limited non-uniformity of the exhaust gas flow and ammonia concentration distribution. Therefore it is necessary to investigate the optimum flow conditions. In order to achieve uniform flow at monolith front face, we are equipped with a various mixed device. In this paper, it is presented that the mixed devices play an important role improvement of flow patterns and particle distributions of NH3 by numerical simulation.

  • PDF

Computational Analysis of Air Flow in a Spinner for Drying LCD Glass Panel (LCD 기판 세정건조용 스피너 설계를 위한 내부유동 해석)

  • Kwak Ho Sang;Lee Sang Woo;Lee Sanghyun;Kim Yong Bum
    • 한국전산유체공학회:학술대회논문집
    • /
    • 2002.10a
    • /
    • pp.114-119
    • /
    • 2002
  • A numerical model is employed for design of a spinner device to dry the 5-th generation LCD glass panel. The turbulent flow in a spinner is driven by rotation of a large disk and suction by the exhaust system connected to vacuum chamber, which is simulated by using the FLUENT package. Based on numerical simulation, the required capacity of exhaust system is assessed. The effects of the presence of cover on the flow characteristics are examined. A computational trouble shooting is attempted to resolve the problem of panel rising which occurred in real experiments.

  • PDF

Primary Research on Theoretical Performance and Powder Supply Characteristics of Powder Rocket

  • Deng, Zhe;Hu, Chun-bo;Hu, Song-qi;Xu, Yi-hua
    • International Journal of Aerospace System Engineering
    • /
    • v.2 no.2
    • /
    • pp.1-5
    • /
    • 2015
  • The powder propellant rocket which uses micron-sized particles as fuel is storable and costly. Functions like thrust control and multiple-ignition can be realized by changing powder mass flow rate. In this paper, we discuss the theoretical performance of bi-propellant and mono-propellant powder rocket. When used as the fluidization gas, helium can improve specific impulse dramatically. The stability of the powder feeding device is preliminarily quantified through metal/N2O powder rocket hot fire tests.