Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A complex-valued resonance model for axisymmetric screech tones in
  supersonic jets   We model the resonance mechanism underpinning generation of A1 and A2 screech
tones in an under-expanded supersonic jet. Starting from the resonance model
recently proposed by \cite{mancinelli2019screech}, where the
upstream-travelling wave is a neutrally-stable guided jet mode, we here present
a more complete linear-stability-based model for screech prediction. We study
temperature and shear-layer thickness effects and show that, in order to
accurately describe the experimental data, the effect of the finite thickness
of the shear layer must be incorporated in the jet-dynamics model. We then
present an improved resonance model for screech-frequency predictions in which
both downstream- and upstream-travelling waves may have complex wavenumber and
frequency. This resonance model requires knowledge of the reflection
coefficients at the upstream and downstream locations of the resonance loop. We
explore the effect of the reflection coefficients on the resonance model and
propose an approach for their identification. The complex-mode model identifies
limited regions of frequency-flow parameter space for which the resonance loop
is amplified in time, a necessary condition for the resonance to be sustained.
This model provides an improved description of the experimental measurements.

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The categories of this paper are: mtrl-th
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The categories of this paper are: cmp-lg
2
The categories of this paper are: math
7
The categories of this paper are: hep-th
33
The categories of this paper are: plasm-ph
32
The categories of this paper are: atom-ph
4
The categories of this paper are: cond-mat
27
The categories of this paper are: comp-gas
26
The categories of this paper are: bayes-an
1
The categories of this paper are: cs
18
The categories of this paper are: econ
19
The categories of this paper are: eess
17
The categories of this paper are: q-fin
30
The categories of this paper are: q-alg
11
The categories of this paper are: hep-lat
10
The categories of this paper are: q-bio