Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Predicting transition from selective withdrawal to entrainment in two
  fluid stratified systems   Selective withdrawal is a desired phenomenon in transferring oil from large
caverns in US Strategic petroleum reserve, because entrainment of oil at the
time during withdrawal poses a risk of contaminating the environment. In order
to predict a critical submergence depth at a critical flow rate, a selective
withdrawal experiment at a high Reynolds Number was conducted. A tube was
positioned through a liquid-liquid interface that draws the lower liquid
upwards. Analysis of the normal stress balance across the interface produced a
Weber number, utilizing dynamic pressure scaling, that predicted the transition
to entrainment. An inviscid flow analysis, using Bernoulli's principle,
assuming an ellipsoidal control volume surface for the iso-velocity profile
produced a linear relationship between the Weber number and the scaled critical
submergence depth. The analytical model was validated using the experimental
data resulting in a robust model for predicting transition from selective
withdrawal to entrainment.

28
The categories of this paper are: alg-geom
20
The categories of this paper are: acc-phys
36
The categories of this paper are: cmp-lg
6
The categories of this paper are: astro-ph
35
The categories of this paper are: mtrl-th
17
The categories of this paper are: q-fin
2
The categories of this paper are: math
21
The categories of this paper are: adap-org
5
The categories of this paper are: gr-qc
23
The categories of this paper are: solv-int
18
The categories of this paper are: econ
13
The categories of this paper are: quant-ph
26
The categories of this paper are: bayes-an
31
The categories of this paper are: ao-sci
15
The categories of this paper are: nucl-ex
8
The categories of this paper are: hep-ex