# Aerogrid¶

class sharpy.aero.models.aerogrid.Aerogrid[source]

Aerogrid is the main object containing information of the grid of panels

It is created by the solver sharpy.solvers.aerogridloader.AerogridLoader

static compute_gamma_dot(dt, tstep, previous_tsteps)[source]

Computes the temporal derivative of circulation (gamma) using finite differences.

It will use a first order approximation for the first evaluation (when len(previous_tsteps) == 1), and then second order ones.

$\left.\frac{d\Gamma}{dt}\right|^n \approx \lim_{\Delta t \rightarrow 0}\frac{\Gamma^n-\Gamma^{n-1}}{\Delta t}$

For the second time step and onwards, the following second order approximation is used:

$\left.\frac{d\Gamma}{dt}\right|^n \approx \lim_{\Delta t \rightarrow 0}\frac{3\Gamma^n -4\Gamma^{n-1}+\Gamma^{n-2}}{2\Delta t}$
Parameters
• dt (float) – delta time for the finite differences

• tstep (AeroTimeStepInfo) – tstep at time n (current)

• previous_tsteps (list(AeroTimeStepInfo)) – previous tstep structure in order: [n-N,..., n-2, n-1]

Returns

first derivative of circulation with respect to time

Return type

float