Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Compressible Flow at High Pressure with Linear Equation of State   Compressible flow varies from ideal-gas behavior at high pressures where
molecular interactions become important. Density is described through a cubic
equation of state while enthalpy and sound speed are functions of both
temperature and pressure, based on two parameters, A and B, related to
intermolecular attraction and repulsion, respectively. Assuming small
variations from ideal-gas behavior, a closed-form solution is obtained that is
valid over a wide range of conditions. An expansion in these
molecular-interaction parameters simplifies relations for flow variables,
elucidating the role of molecular repulsion and attraction in variations from
ideal-gas behavior. Real-gas modifications in density, enthalpy, and sound
speed for a given pressure and temperature lead to variations in many basic
compressible flow configurations. Sometimes, the variations can be substantial
in quantitative or qualitative terms. The new approach is applied to
choked-nozzle flow, isentropic flow, nonlinear-wave propagation, and flow
across a shock wave, all for the real gas. Modifications are obtained for
allowable mass-flow through a choked nozzle, nozzle thrust, sonic wave speed,
Riemann invariants, Prandtl's shock relation, and the Rankine-Hugoniot
relations. Forced acoustic oscillations can show substantial augmentation of
pressure amplitudes when real-gas effects are taken into account. Shocks at
higher temperatures and pressures can have larger pressure jumps with real-gas
effects. Weak shocks decay to zero strength at sonic speed. The proposed
framework can rely on any cubic equation of state and be applied to
multicomponent flows or to more-complex flow configurations.

18
The categories of this paper are: econ
4
The categories of this paper are: cond-mat
32
The categories of this paper are: atom-ph
17
The categories of this paper are: q-fin
9
The categories of this paper are: nlin
12
The categories of this paper are: nucl-th
5
The categories of this paper are: gr-qc
1
The categories of this paper are: cs
23
The categories of this paper are: solv-int
16
The categories of this paper are: stat
6
The categories of this paper are: astro-ph
37
The categories of this paper are: supr-con
25
The categories of this paper are: patt-sol
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The categories of this paper are: math-ph
24
The categories of this paper are: dg-ga
34
The categories of this paper are: chem-ph