Dynamic Leidenfrost behaviors of different fluid drops on superheated surface: Scaling for vapor film thickness

2019 ◽  
Vol 31 (10) ◽  
pp. 101702 ◽  
Author(s):  
Junseok Park ◽  
Dong Eok Kim
Keyword(s):  
Film Thickness ◽  
Vapor Film ◽  
Surface Scaling ◽  
Superheated Surface

Study on the Behavior of a Wetted Area Right After Liquid-Wall Contact in Pool Film Boiling

2000 ◽  
Author(s):  
Hiroyasu Ohtake ◽  
Hiroyuki Satoh ◽  
Yasuo Koizumi
Keyword(s):  
Temperature Fluctuation ◽  
Contact Angles ◽  
Film Boiling ◽  
Vapor Film ◽  
Saturated Water ◽  
Wall Superheat ◽  
Liquid Injection ◽  
Wetted Area ◽  
Superheated Surface ◽  
Liquid Wall

Abstract The behaviors of the rewetting on pool film boiling, focusing on observations of a collapse of a vapor film, a wetted area and a contact angle on a superheated surface were investigated experimentally. Using a U-shaped platinum wire with 2 mm diameter and 140 mm long, pool film-boiling experiments were performed for saturated water at atmospheric pressure. After a stable film-boiling state at a prescribed initial wall temperature was established, saturated water from a nozzle, set above the test wire, was injected on the superheated surface in the stable film-boiling, then artificial rewetting was forced on the superheated surface. During forming the artificial rewetting, the temperature fluctuation right under the liquid injection and the behavior of the rewetting were obtained for the initial wall temperatures of 600, 420, 400 and 300 degree-C, respectively. The present experimental results showed that the propagative collapse of the vapor film occurred when the initial wall superheat was below 300 K. On the other hand, above the initial wall superheat of 320 K, the rewetting declined after liquid injection was finished then film boiling recovered. The temperature was related to the thermodynamic limit of superheat, according to the measured temperature fluctuation during supplying the liquid. The wetted area right after liquid-wall contact and the advancing velocity of the rewetting front increased as the initial wall superheat decreased. The measured angles between the liquid-vapor interfacial line and the heated wall corresponded to dynamic contact angles were close to the dynamic advancing contact-angles in room temperature.

The behavior of a vapor film on a highly superheated surface immersed in subcooled water

2005 ◽  
Vol 43 (1) ◽  
pp. 103-118 ◽  
Author(s):  
V. S. Grigor?ev ◽  
V. G. Zhilin ◽  
Yu. A. Zeigarnik ◽  
Yu. P. Ivochkin ◽  
V. V. Glazkov ◽  
...  
Keyword(s):  
Vapor Film ◽  
Subcooled Water ◽  
Superheated Surface

Some Consideration on the Edge Condition of a Finite-Size Horizontal Downward-Facing Plate in Subcooled Pool Film Boiling

2017 ◽  
Author(s):  
Kaoru Toyoda ◽  
Shintaro Murakami
Keyword(s):  
Boundary Layer ◽  
Film Thickness ◽  
Flow Direction ◽  
Finite Size ◽  
Edge Condition ◽  
Vapor Flow ◽  
Vapor Film ◽  
Two Phase ◽  
Plate Edge ◽  
Liquid Boundary

Reliability and usability of the analytical results regarding vapor film thickness, vapor velocity, and the mass flow rate of vapor at the plate edge and Nusselt number averaged over the surface are examined to clarify vapor outflow conditions at the plate edge which has not been clarified by conventional experiments. For analysis, we adopt the two-phase boundary layer theory and the integral method which can determine the variation of vapor film thickness in the vapor flow direction to set a velocity profile in a vapor film and a temperature profile in a liquid boundary layer reasonably. In the calculation of the analysis, the inclination angle of the vapor-liquid interface at the plate edge is varied ranging from 0 to 90 degrees. The results of the analysis provide useful guides to future studies in observing the vapor flow conditions in detail and measuring the vapor flow velocity at the plate edge.

scholarly journals Liquid-solid contact state and fluctuation of the vapor film thickness of a drop impinging on a heated surface.

1988 ◽  
Vol 21 (5) ◽  
pp. 463-468 ◽  
Author(s):  
SHIGEAKI INADA ◽  
YOSHIKI MIYASAKA ◽  
KENJI SAKAMOTO ◽  
KEIJI HOJO
Keyword(s):  
Film Thickness ◽  
Heated Surface ◽  
Vapor Film ◽  
Solid Contact ◽  
Contact State
Sign in / Sign up

Export Citation Format

Share Document