Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Hydrodynamic Lift on Boats   Boats float supported only by buoyancy at rest and at very low speeds. As the
speed increases, a hull capable of planing makes a sharp transition to a
lifting surface while plowing up the bow wave. As the speed increases further
the boat planes, and at a high enough speed buoyancy becomes negligible;
hydrodynamic lift carries the weight. More generally, any flow past a lifting
surface generates a force perpendicular to the flow once the flow separates
from the trailing edge without backflow (without vortex formation). Wings,
hydrofoils, sails, and propellers are examples of lifting surfaces. The idea of
a planing hull as lifting surface has been discussed inconclusively in the
literature. We provide evidence for the onset of lift before planing and also
produce an empirically correct lift coefficient for the planing of a v-bottom
(prismatic shape) hull at high enough speeds that the wet surface area is
confined roughly to a triangular shape near the transom. Our model follows our
calculation of the lift on a fully submerged delta wing hydrofoil. The lift is
reduced once the hydrofoil pierces the air-water interface.

21
The categories of this paper are: adap-org
35
The categories of this paper are: mtrl-th
9
The categories of this paper are: nlin
34
The categories of this paper are: chem-ph
7
The categories of this paper are: hep-th
14
The categories of this paper are: math-ph
27
The categories of this paper are: comp-gas
25
The categories of this paper are: patt-sol
19
The categories of this paper are: eess
0
The categories of this paper are: hep-ph
11
The categories of this paper are: hep-lat
26
The categories of this paper are: bayes-an
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The categories of this paper are: cmp-lg
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The categories of this paper are: funct-an
1
The categories of this paper are: cs
18
The categories of this paper are: econ