scholarly journals Investigation of Dynamic Characteristics of Liquid Nitrogen Droplet Impact on Solid Surface

2022 ◽  
Vol 14 (2) ◽  
pp. 710
Author(s):  
Ke Zhao ◽  
Yang Ding
Keyword(s):  
Liquid Nitrogen ◽  
Solid Surface ◽  
Dynamic Characteristics ◽  
Wall Temperature ◽  
Spray Cooling ◽  
Droplet Impact ◽  
Spreading Factor ◽  
Normal Medium ◽  
The Common ◽  
Cooling Technology

Liquid nitrogen spray cooling technology exhibits excellent heat transfer efficiency and environmental protection performance. The promotion of this technology plays an important role in improving the sustainable development of the refrigeration industry. In order to clarify its complex microscale behavior, the coupled Level Set-VOF method was adopted to study the dynamic characteristics of liquid nitrogen droplet impact on solid surface in this paper. The spreading behaviors under various factors (initial velocity, initial diameter, wall temperature, and We number) were systematically analyzed. The results show that the spreading behaviors of liquid nitrogen droplet share the same process with the normal medium, which are rebound, retraction, and splashing. For the droplet with smaller velocity and diameter, Rebound is the common phenomenon due to the smaller kinetic energy. With the increase of droplet diameter (0.2 mm to 0.5 mm) and velocity (0.1 m/s to 5 m/s), the spreading factor increases rapidly and the spreading behaviors evolve into retraction and splashing. The increase of wall temperature accelerates the droplets spreading, and the spreading factor increases accordingly. For the liquid nitrogen droplets hit the wall, the dynamic behaviors of rebound (We < 0.2), retraction (0.2 < We < 4.9), and splashing (We > 4.9) will occur with the droplet weber number increased, which are consistent with the common medium. However, due to liquid nitrogen having lower viscosity and surface tension, the conditions of morphological transformations are different from the common media. The maximum spreading diameter has a power correlation with We, the power index of We is 0.306 for liquid nitrogen, lager than common medium (0.25). The reasons are: (1) the better wettability of liquid nitrogen, and (2) the vapor generated by the violent phase change ejects along the axial direction. The article will provide a certain theoretical basis for liquid nitrogen spray cooling technology, and can also enrich the flow dynamics of cryogenic fluids.

Si(Li) detector for microanalysis cooled by thermoelectric device

1992 ◽  
Vol 50 (2) ◽  
pp. 1736-1737
Author(s):  
Shaul Barkan
Keyword(s):  
Solid State ◽  
Liquid Nitrogen ◽  
Thermoelectric Device ◽  
Peltier Cooler ◽  
Complicated Process ◽  
The Common

Cooling down solid state detecors, with other different way then liquid Nitrogen, is a goal of many vendors and customers since the invention of these detectors. THe disadvantage of the common way of liquid Nitrogen is first the inavailibility of the LN in many uses (like space military and any other applications that are not done inside a well organize Laboratory). The use of LN also considers as a Labor consumer in addition to the big dewar that has to be added to any detector for storing the LN, the boiling of the LN, may cause microphonics problesm and the refiling of the dewar in many Labs is a complicated process due to inconvenience location of the microscope.In this paper I will show a spectra result of 10mm2 SiLi detector for microanalysis use, cooled by peltier cooler. The peltier cooler has the advantage of non-microphonics and non-labor needed (like adding LN to the dewar).

scholarly journals Encapsulation of Active Pharmaceutical Ingredients in Lipid Micro/Nanoparticles for Oral Administration by Spray-Cooling

Pharmaceutics ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1186
Author(s):  
Carmen S. Favaro-Trindade ◽  
Fernando E. de Matos Junior ◽  
Paula K. Okuro ◽  
João Dias-Ferreira ◽  
Amanda Cano ◽  
...  
Keyword(s):  
Oral Administration ◽  
Raw Materials ◽  
Low Cost ◽  
Pharmaceutical Formulations ◽  
Spray Cooling ◽  
Active Pharmaceutical Ingredients ◽  
Pharmaceutical Ingredients ◽  
Taste And Odor ◽  
Cooling Technology ◽  
Simple Technology

Nanoencapsulation via spray cooling (also known as spray chilling and spray congealing) has been used with the aim to improve the functionality, solubility, and protection of drugs; as well as to reduce hygroscopicity; to modify taste and odor to enable oral administration; and many times to achieve a controlled release profile. It is a relatively simple technology, it does not require the use of low-cost solvents (mostly associated to toxicological risk), and it can be applied for lipid raw materials as excipients of oral pharmaceutical formulations. The objective of this work was to revise and discuss the advances of spray cooling technology, with a greater emphasis on the development of lipid micro/nanoparticles to the load of active pharmaceutical ingredients for oral administration.

Hollow droplet impact on a solid surface

2021 ◽  
pp. 103740
Author(s):  
Mahdi Nasiri ◽  
Ghobad Amini ◽  
Christian Moreau ◽  
Ali Dolatabadi
Keyword(s):  
Solid Surface ◽  
Droplet Impact

scholarly journals Air film evolution during droplet impact onto a solid surface

2021 ◽  
Vol 33 (9) ◽  
pp. 092107
Author(s):  
Zunru Fu ◽  
Haichuan Jin ◽  
Jun Zhang ◽  
Tianyou Xue ◽  
Dongsheng Wen
Keyword(s):  
Solid Surface ◽  
Droplet Impact ◽  
Air Film

Droplet Impact on a Solid Surface

2010 ◽  
pp. 183-211 ◽  
Author(s):  
António L. N. Moreira ◽  
A. S. Moita ◽  
S. Chandra
Keyword(s):  
Solid Surface ◽  
Droplet Impact

Near Field Characteristics of Droplet Impact on Solid Surface using FTIR technique

2020 ◽  
Vol 2020 (0) ◽  
pp. OS06-29
Author(s):  
Hidehiko TAKAHASHI ◽  
Masao WATANABE ◽  
Kazumichi KOBAYASHI ◽  
Hiroyuki FUJII
Keyword(s):  
Solid Surface ◽  
Near Field ◽  
Droplet Impact ◽  
Ftir Technique

scholarly journals Pressure generated at the instant of impact between a liquid droplet and solid surface

2018 ◽  
Vol 5 (12) ◽  
pp. 181101 ◽  
Author(s):  
Y. Tatekura ◽  
M. Watanabe ◽  
K. Kobayashi ◽  
T. Sanada
Keyword(s):  
Solid Surface ◽  
Shape Factor ◽  
Liquid Droplet ◽  
Pressure Rise ◽  
Propagation Speed ◽  
Spherical Shape ◽  
Water Hammer ◽  
Droplet Impact ◽  
Maximum Pressure ◽  
The Impact

The prime objective of this study is to answer the question: How large is the pressure developed at the instant of a spherical liquid droplet impact on a solid surface? Engel first proposed that the maximum pressure rise generated by a spherical liquid droplet impact on a solid surface is different from the one-dimensional water-hammer pressure by a spherical shape factor (Engel 1955 J. Res. Natl Bur. Stand. 55 (5), 281–298). Many researchers have since proposed various factors to accurately predict the maximum pressure rise. We numerically found that the maximum pressure rise can be predicted by the combination of water-hammer theory and the shock relation; then, we analytically extended Engel’s elastic impact model, by realizing that the progression speed of the contact between the gas–liquid interface and the solid surface is much faster than the compression wavefront propagation speed at the instant of the impact. We successfully correct Engel’s theory so that it can accurately provide the maximum pressure rise at the instant of impact between a spherical liquid droplet and solid surface, that is, no shape factor appears in the theory.

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