| Project/Area Number |
16560176
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Thermal engineering
|
|---|
| Research Institution | Yokohama National University |
|---|
Principal Investigator |
OKUYAMA Kunito Yokohama National University, Graduate School of Engineering, Professor, 大学院・工学研究院, 教授 (60204153)
|
|---|
| Project Period (FY) |
2004 – 2005
|
| Project Status |
Completed (Fiscal Year 2005)
|
| Budget Amount *help |
¥2,800,000 (Direct Cost: ¥2,800,000)
Fiscal Year 2005: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 2004: ¥1,700,000 (Direct Cost: ¥1,700,000)
|
|---|
| Keywords | Solid-liquid contact / Spontaneous nucleation / Limit of liquid superheat / Rapid evaporation / Contact temperature measurement / Observation of boiling behavior / Surface cooling rate |
|---|
| Research Abstract |
When a high temperature liquid contacts with a volatile low temperature liquid and the contact interface temperature is beyond the superheat limit of the low temperature liquid, spontaneous nucleation and resulting vapor explosion may occur. In the present study, the contact of liquid with a high temperature solid and the resulting bubble nucleation phenomenon were investigated using a rapid heating method. A small platinum film heater immersed in ethyl alcohol was powered by a rectangular pulse having two or three-stages. The collapse of a coalesced bubble, which is formed as the result of spontaneous nucleation over the heater surface by high pulse of the first stage, causes the solid-liquid re-contact. The pulse power of the second stage was changed in order to control the heater temperature at the contact. The heater surface temperature was measured by means of the resistance thermometry. The third stage of negligible power enabled the surface temperature measurement during the contact. Fine bubbles appeared during the contact and its number becomes maximal when the heater temperature was around the homogeneous nucleation temperature of the liquid. At higher temperatures, the vapor film remained on the entire surface even after the collapse of the coalesced bubble.
|
