Commit d74b943

<h3>Methods</h3>

<ul class="links">

<li><a href="methods/aerodynamics.html">Aerodynamics</a></li>

<li><a href="methods/propulsion.html">Propulsion</a></li>

<li><a href="methods/weights.html">Weights</a></li>

<li><a href="methods/cg.html">Center of Gravity</a></li>

<li><a href="methods/dynamics.html">Flight Dynamics</a></li>

<li><a href="methods/costs.html">Costs</a></li>

<li><a href="methods/geometry.html">Geometry</a></li>

<li><a href="methods/noise.html">Noise</a></li>

</ul>

<h2>Methods</h2>

<p>

Methods are where the proverbial rubber begins to meet the road in

SUAVE. Up until this point, the User Guide has covered primarily how

SUAVE stores and organizes data. Methods are how SUAVE uses that

data to calculate performance and characteristics of the vehicle.

</p>

<p>

Methods themselves are design to be relatively "atomic" -

self-contained, straight-forward input-output functions. This both

allows some of them to be broken out of SUAVE entirely and used in

much the same way as NumPy or SciPy functions, but "within" SUAVE

it allows them to be swapped in and out or assembled into more

complicated Analyses, which are covered in a separate section.

</p>

<p>

Generally speaking, SUAVE Methods are sensitive to their input

parameters and data types. They are "Garbage In, Garbage Out" and

are not robust against non-physical or physically impossible setups.

If methods seem to be returning non-sensical, non-numerical, or

unconverging values, they are likely reflecting the physical

impossibility of the inputs.

</p>

<p>

Because the Methods can be driven to such extremes by a wide

variety of conditions, there is little customized error handling.

The burden lies on the user to ensure that their input models and

data are sensible and well structured.

</p>

<h3>Aerodynamics</h3>

<p>

Aerodynamic Methods are those used to solve aerodynamic equations

for input vehicle/wing geometries. They include lifting line and

potential flow solvers like the Weissinger Vortex Lattice and

Athena Vortex Lattice methods, as well inviscid and Euler CFD

solutions through interface with the SU2 CFD package.

</p>

<p>

They are typically used to resolve lift and drag vectors for

aerodynamic surfaces and vehicles. Where the solver also

provides pertinent stability information, processing of this

information is performed with a separate and Analysis.

</p>

<h3>Propulsion</h3>

<p>

Propusion Methods include those used in the analysis of propulsion

systems, including turbofans, propeller systems, and rocket motors.

They include methods for sizing these systems and resolving thrust

vectors.

</p>

Because propulsors are usually highly coupled to the energy network

of a vehicle, many of these methods are only meaningful when used to

analyze a fully described energy network. For instance, use of

propeller methods on a battery powered vehicle without consideration

of the stateof charge and available voltage of the battery may

overestimate the thrust the propeller could provide.

<h3>Weights</h3>

Weights are those Methods concerned with estimating the mass and

weight of a vehicle and its various components. At present, these

Methods are separated into two types - Correlations, and Buildups.

<p>

Correlation methods use historical data to estimate the weight of a

new aircraft of similar configuration and operational plan. SUAVE

utilizes Methods of this type to estimate the weight of most

aircraft including tube-and-wing civil transports, general aviation

craft, and blended-wing-bodies. Buildups use ground-up physics based

component sizing to arrive at a weight estimate. SUAVE uses Methods

of this type for electric vertical take-off and landing aircraft.

</p>

<h3>Center of Gravity</h3>

<p>

Center of Gravity (CG) Methods estimate the location of a vehicle's

CG, the CGs of its components, and fuel loads. These methods are

typically coupled with methods in the Flight Dynamics library for

estimating vehicle stability parameters, but may be used

independently if desired. They require all components to be

assigned individual origin attributes in a consistent and cohesive

manner.

</p>

<h3>Flight Dynamics</h3>

<p>

Flight Dynamics Methods are those concerned with estimating a

vehicle's static and dynamic stability margins and derivatives. They

are built into SUAVE and may therefore be used separately from or

in addition to aerodynamic solvers such as AVL which provide

similar information.

</p>

<h3>Costs</h3>

<p>

Cost Methods estimate the industrial and operating costs of a

vehicle based on the physical and Cost attributes assigned to the

model.

</p>

<h3>Geometry</h3>

<p>

Geometry Methods are largely supporting methods used in substeps of

other Methods, such as processing data for airfoils, cross-sectional

areas inside of jet engines, or projected planforms of aerodynamic

surfaces. They may however, also prove useful when used outside of

SUAVE Methods as independent functions.

</p>

<h3>Noise</h3>

<p>

Noise Methods are used to estimate jet-wash, propeller, airframe,

and other sources of operational noise when the aircraft is in

operation. At present, SUAVE's methods for noise estimation include

a number of correlative and low-fidelity physics based methods.

</p>