A Study on the Thrust Force of a Narrowly Spaced Disk Valve

좁은 틈새 원판 밸브의 추력에 관한 연구

One of the important characteristics of a disk valve is the thrust force. This thrust force has close relationship to the clearance between valve and valve seat in the disk valve. When the clearance is very small, it is very important to analyze the thrust force. This paper deals with the variation of the thrust force by comparing the experimental ed results and theoretical results in accordance with d the valve clearance. In case of the theoretical problems, the pressure gradient of the radial flow in a narrowly spaced disks was calculated by Sui Lin and Pai-Mow Lee already. Therefore, the thrust force of the disk valve was computed by utilizing this pressure gradient in the radial flow. In the experiment, the hydraulic oil which has high viscosity was used. Making the comparative study of the calculated results and the experimental results, the characteristics of the thrust force in the disk valve were investigated. The results obtained are as follows: 1. When the disk valve clearance was comparatively small, the experimental values had fairly good agreement with the calculated values independently of inlet pressure and valve size. 2. When the disk valve size was constant in the wide range of the disk valve clearance, the lower the inlet pressure was, the better the agreement between the experimental values and the calculated values was. 3. In case of the small clearance, the thrust force was depended on the outer diameter of the disk valve. In opposite case the thrust force was constant as the disk valve size varied.

좁은 틈새를 가진 원판밸브의 추력에 대한 이론적 해석 및 실험 결과로부터 다음과 같이 요약할 수 있다. 1. 원판 밸브의 틈새가 비교적 작은 경우(H/D sub(1)가 0.1 이하) 즉, 유량이 적을 때에는 점성류가 지배적이고 이론식으로부터 추력을 높게 예측할 수 있었다. 2. 압력의 영향에 대한 추력은 입구 압력이 낮을수록 이론결과와 실험결과가 잘 일치하고 높을수록 관성의 영향이 크게 나타나는 경향을 보였다. 3. 밸브 크기 변화에 대한 추력의 영향은 D sub(2)/D sub(1)=>4.6에서는 포물선적으로 감소하고 그 이하에서는 직선적으로 감소하였다.