CAVITY
일정한 속도의 액체가 면적이 작은 부위(수축부 Vena Contracta)를 지날 때 유체의 속도(V)는 빨라지고 압력(P)은 떨어진다, 이때 액체압력이 그 액체의 증기압(Pv)보다 낮아지면 기포가 발생 Vapor 상태가 되는데 이것을 Cavity라 한다. 이 기포는 다시 압력이 상승함에 따라서 밸브Trim 이나 Body 내벽에서
Figure 9. Electrostatic field simulation.
(a) The electrostatic field(E.F) contour lines are plotted
(b) The absolute value of the E.F against height.
FE-SEM micrographs of electrospun fiber mats at various surface velocities:
4.3 m/s, (b) 8.6 m/s,
(c) 12.9 m/s, and (d) 17.2 m/s.
(The direction of rotating drum is downward.)
1) 열교환기의 종류와 특징 및 적용분야에 대해 간단히 논하시오.
<종류>
1) 원통 다관식 (Shell&Tube) 열교환기
가장 널리 사용되고 있는 열교환기로 폭넓은 범위의 열전달량을 얻을 수 있으므로 적용범위가 매우 넓고, 신뢰성과 효율이 높다.
2) 이중관식(Double Pipe Type) 열교환기
외관 속에
chestnut in the
traces.
Framed in the glass window of the narrow buggy is the
stern figure of an Amish man in black topcoat and
flatbrimmed hat, his bonneted wife in muted colors,
the face of a boy, attired like his father, peering
out.
The horses breath smokes on the frosty air, the buggy
CREAKS on its springs, and theres the rhythmic CLIP-
CLOP OF HOOVES on the pavement.
4 ANOTHER LANE
??
Two A
chestnuts and oaks, numbers of small
animals gambol. Squirrels and rabbits, hedgehogs and
foxes, all manner of creatures leap and frolic about the
feet of a curious young man. This is JACK O THE GREEN.
His hair is long and unshorn and he wears a costume woven
from ivy leaves, skins and vines. On his feet are bark
sandals. His features are tanned berry-brown and woven
into his tangled locks is a w