Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: All you need is time to generalise the Goman-Khrabrov dynamic stall
  model   Dynamic stall on airfoils negatively impacts their aerodynamic performance
and can lead to structural damage. Accurate prediction and modelling of the
dynamic stall loads are crucial for a more robust design of wings and blades
that operate under unsteady conditions susceptible to dynamic stall and for
widening the range of operation of these lifting surfaces. Many dynamic stall
models rely on empirical parameters that need to be obtained from experimental
or numerical data which limits their generalisability. Here, we introduce
physically derived times scales to replace the empirical parameters in the
Goman-Khrabrov dynamic stall model. The physics-based time constants correspond
to the dynamic stall delay and the decay rate of post-stall load fluctuations.
The dynamic stall delay is largely independent of the type of the motion, the
Reynolds number, and the airfoil geometry and is described as a function of a
normalised instantaneous pitch rate. The post-stall decay rate is independent
of the motion kinematics and is directly related to the Strouhal number of the
post-stall vortex shedding. The general validity of our physics-based time
constants is demonstrated using three sets of experimental dynamic stall data
covering various airfoil profiles, Reynolds numbers varying from 75'000 to
1'000'000, and sinusoidal and ramp-up pitching motions. The use of
physics-based time constants generalises the Goman-Khrabrov dynamic stall model
and extends its range of application.

20
The categories of this paper are: acc-phys
12
The categories of this paper are: nucl-th
28
The categories of this paper are: alg-geom
5
The categories of this paper are: gr-qc
25
The categories of this paper are: patt-sol
24
The categories of this paper are: dg-ga
31
The categories of this paper are: ao-sci
0
The categories of this paper are: hep-ph
30
The categories of this paper are: q-alg
7
The categories of this paper are: hep-th
17
The categories of this paper are: q-fin
35
The categories of this paper are: mtrl-th
32
The categories of this paper are: atom-ph
11
The categories of this paper are: hep-lat
23
The categories of this paper are: solv-int
19
The categories of this paper are: eess