In case of a low speed gearing in the automatic transmission, since the torque is increased, it is difficult to secure a good feeling on gear shift of transmission. It is possible to improve the shift feeling on transmission by applying a one-way clutch in case of the gear shift from the first stage to the second stage. But in case of the gear shift from the second stage to the third stage, it is difficult to secure a good feeling on gear shift of transmission because the hydraulic components are directly controlled simultaneously. In this study, a shift performance of an automatic transmission was investigated as a basic study to solve these problems. The subjects of this study are 2-3 step upshifting gearing process and the performance data such as the pressure characteristics and torque of the transmission according to the amount of the throttle valve opening are analyzed on basis of experiment with an actual vehicle. As a result, the transient time of the shift is closely related to the amount of the throttle valve, opening and the time point at which the shifting ends is shortened when the throttle valve opening reaches 30% of the opening amount.
Flow visualization of Butterfly valve is tested five cases(15°, 30°, 45°, 60° and 90°) of vlave opening angle. Measurement by the PIV(Particle Image Velocimetry) was conducted to investigate the flow characteristics of butterfly valve about discharge of dam.. Flow behaviors such as instantaneous and time-mean velocity vectors are investigated each cases. The results from flow visualization using PIV through the video which do not contain a cavitation phenomenon was confirmed in accordance with the valve opening. Performs valve opening and the flow properties of the Karman vortex generated by the frequency analysis is 90° was calculated the frequency of the butterfly valve applied to the actual dam. Butterfly valve for the emergency discharge valve is susceptible to cavitation caused by the valve opening 90° and repeat the cycle in the valve side of the vortex emission system is a high possibility of damage due to fatigue.
The performance of spray vale using three nozzles has been investigated experimentally. Experimental apparatus is composed of the steam line and water line. Capacity 20kW electric heaters were used to produce the 1l0oC steam. The 300C water was produced using a water bath. Water outlet temperature is measured for each model to evaluate the performance of the nozzle.
A valve open/close degree measuring device is used for an indicator of a valve actuator. This device indicates an opening and closing of a valve or throttle in a hydraulic actuator. In ship, equipments requires safe and robust because of a rough environment and a specific condition during a voyage. Thus, the open/close degree measuring device must be developed which can be used at an outdoor environment. This study developed the open/close degree measuring device using a volumetric measuring method(25㎖/100㎖). The housing of the open/close degree measuring device was made by a stainless steel with surface painting after an anodizing coating.
해수침투 방지나 대수층 인공함양을 위하여 다수의 관정을 통하여 대수층으로 물을 주입하는 공법이 있다. 이러한 공법의 경우 소기의 목적을 달성하기 위해서는 관정의 위치와 주입량, 그리고 결과되는 관정의 지하수위 등이 별도의 지하수 모델링을 통하여 결정된다. 주입수는 통상 관망을 통하여 관정으로 공급되는 데 이 때 관망에는 관정별 주입량을 조절하기 위한 밸브가 설치된다. 본 연구에서는 다수의 주입 관정이 연결된 관망에서 사전에 산정된 주입량 분포를 준수하기 위한 밸브 개도와 주입관망 가동에 필요한 펌프 최소 소요양정 산정방안을 제시하였다. 본 연구결과는 주입군정 운영의 정밀도를 향상시키는 데 기여할 수 있다.