Edit on GitHub

Library

Public API

DLM.influence_matrix — Function
influence_matrix(ω, U, M, xyz::AbstractVector{<:AbstractArray{<:Number, 3}}, symmetric::AbstractVector; kernel=QuarticKernel())
influence_matrix(ω, U, M, xyz::AbstractArray{<:Number, 3}, symmetric; kernel=QuarticKernel())
influence_matrix(ω, U, M, xyzr::AbstractArray{<:Number, 3}, xyzs::AbstractArray{<:Number, 3}, symmetric; kernel=QuarticKernel())

Fills in aerodynamic influence coefficient matrix. Returns aerodynamic influence coefficient matrix AIC with shape (nir, njr, nis, njs). For a non-allocating version, see influence_matrix!.

Receiving and sending panel points must be aligned with the x-direction. The freestream velocity must also be aligned in the x-direction.

Arguments

  • ω: oscillation frequency
  • U: freestream velocity
  • M: Mach number (for Prandtl-Glauert compressibility correction)
  • xyzr: definition of receiving panel points with shape: (3, nir, njr)
  • xyzs: definition of sending panel points with shape: (3, nis, njs)
  • symmetric: flag indicating symmetry of each sending panel
  • kernel: indicates which approximation of the kernel should be used
source
DLM.influence_matrix! — Function
influence_matrix!(AIC, ω, U, M, xyz::AbstractVector{<:AbstractArray{<:Number, 3}}, symmetric::AbstractVector; kernel=QuarticKernel())
influence_matrix!(AIC, ω, U, M, xyz::AbstractArray{<:Number, 3}, symmetric; kernel=QuarticKernel())
influence_matrix!(AIC, ω, U, M, xyzr::AbstractArray{<:Number, 3}, xyzs::AbstractArray{<:Number, 3}, symmetric; kernel=QuarticKernel())

Non-allocating version of influence_matrix

source
DLM.pressure_coefficients — Function
pressure_coefficients(AIC, w)

Compute pressure coefficients Cp on each panel, given the downwash w.

Arguments:

  • AIC: aerodynamic influence coefficient matrix with shape (nir, njr, nis, njs)
  • w: downwash on each panel, with shape (nir, njr)
source
DLM.AbstractKernel — Type
AbstractKernel()

Abstract type for approximation of the planar and nonplanar influence terms in the numerator of the doublet lattice method kernel

source
DLM.ParabolicKernel — Type
ParabolicKernel()

Parabolic approximation for the planar and nonplanar influence terms in the numerator of the doublet lattice method kernel.

source
DLM.QuarticKernel — Type
QuarticKernel()

Quartic approximation for the planar and nonplanar influence terms in the numerator of the doublet lattice method kernel.

source

Private API

DLM.approximate_kernel_integrals — Function
approximate_kernel_integrals(u, k)

Solves for the integrals I0 and J0 using a 12-term exponential approximation given by Desmarais in "AN ACCURATE METHOD FOR EVALUATING THE KERNEL OF THE INTEGRAL EQUATION RELATING LIFT TO DOWNWASH IN UNSTEADY POTENTIAL FLOW".

Arguments

  • u = (MR - x0)/(β^2x0)
  • k = ω*r/U
source
DLM.kernel_coefficients — Function
kernel_coefficients(x0, y0, z0, ω, U, M)

Solves for the kernel coefficients K1 and K2 and their steady state counterparts K10 and K20.

See "A Doublet-Lattice Method for Calculating Lift Distributions on Oscillating Surfaces in Subsonic Flows" by Edward Albano and William P Rodden.

Arguments

  • x0 = x-ξ
  • y0 = y-η
  • z0 = z-ζ
  • ω = frequency
  • U = Velocity
  • M = Mach Number
source
DLM.kernel_numerator — Function
kernel_numerator(ω, U, M, x0, y0, z0, γr, γs)

Solves for the numerator terms of the kernel and subtracts out the steady-state components of these terms.

See "Further Refinement of the Subsonic Doublet-Lattice Method" by William P. Rodden, Paul F. Taylor and Samuel C. McIntosh Jr.

source
DLM.influence_coefficient — Function

influence_coefficient(ω, U, M, (xr, yr, zr), (xi, yi, zi), (xo, yo, zo), chord, λ, γr, γs, kernel)

Solves for the influence coefficient of the sending panel on the receiving panel.

The planar and nonplanar influence terms in the numerator are approximated using the approximation specified by kernel.

See "Further Refinement of the Subsonic Doublet-Lattice Method" by William P. Rodden, Paul F. Taylor and Samuel C. McIntosh Jr.

source
DLM.steady_influence_coefficient — Function
steady_influence_coefficient(M, x0i, y0i, z0i, x0o, y0o, z0o, sγr, cγr)

Solves for the steady component of the influence of the sending panel on the receiving panel using the vortex lattice method.

source

Index