Public Documentation

mutable struct PotentialFlowBody

Defines a rigid body for VortexModel in GridPotentialFlow.jl.

PotentialFlowBody(
    b::Body{N, C};
    U,
    Ω,
    Γ,
    edges,
    σ
) -> PotentialFlowBody

Constructs a potential flow body with shape b, linear velocity U, rotational velocity Ω, and initial circulation Γ. Edges that should be regularized can be specified in edges and their suction parameter ranges in σ, which defaults to zero for each regularized edge.

mutable struct Vortex

Defines a point vortex with x-position x, y-position y, and strength Γ.

Fields

• x::Float64: x: x-coordinate of the vortex position.

• y::Float64: y: y-coordinate of the vortex position.

• Γ::Float64: Γ: Strength of the vortex. Positive if counter-clockwise.

mutable struct VortexModel{Nb, Ne, TS<:Union{Laplacian, GridPotentialFlow.AbstractPotentialFlowSystem}, TU<:Nodes, TE<:Edges, TF<:ScalarData, TX<:VectorData, ILS<:Union{Nothing, ILMSystem}}

Defines a grid-based vortex model with Nb bodies and Ne edges that are regularized. If isshedding is true, the strengths of the last Ne vortices in vortices can be computed in order to regularized the Ne edges.

Fields

• g::PhysicalGrid: g: The grid on which the vortex model is defined.

• bodies::Vector{PotentialFlowBody}: bodies: Bodies in the vortex model.

• vortices::StructArrays.StructVector{Vortex}: vortices: Point vortices in the vortex model.

• U∞::Tuple{Float64, Float64}: U∞: Uniform flow in the vortex model.

• system::Union{Laplacian, GridPotentialFlow.AbstractPotentialFlowSystem}: system: Potential flow system that has to be solved with an AbstractPotentialFlowRHS and an AbstractPotentialFlowSolution to compute the potential flow that governs the vortex model.

• ilsys::Union{Nothing, ILMSystem}

• _nodedata::Nodes: Internal fields

• _edgedata::Edges

• _bodyvectordata::VectorData

• _ψ::Nodes

• _f::ScalarData

• _w::Nodes

• _ψb::ScalarData

Examples

(under construction)

VortexModel(
    g::PhysicalGrid,
    bodies::Vector{PotentialFlowBody},
    vortices::StructArrays.StructVector{Vortex},
    U∞::Tuple{Float64, Float64}
) -> VortexModel{_A, _B, _C, Nodes{Dual, _A1, _B1, Float64, Matrix{Float64}}, _D, ScalarData{_A2, T, _B2}} where {_A, _B, _C<:Union{Laplacian, GridPotentialFlow.AbstractPotentialFlowSystem}, _A1, _B1, _D<:Edges, _A2, T<:Number, _B2<:(AbstractVector)}

Constructs a vortex model using the given function.

length(b::PotentialFlowBody) -> Any

Returns the number of surface points in the body b.

addedmass(vm)

Computes the translational coefficients of the added mass matrix of the bodies in the vortex model vm.

getU(b::PotentialFlowBody) -> Tuple{Float64, Float64}

Returns the linear velocity of the body b.

getrange(
    b::AbstractVector{PotentialFlowBody},
    i::Int64
) -> Any

Returns the subrange of indices in the global set of surface point data corresponding to body i in b.

getvortexpositions(vm)

Returns the positions of the vortices in the vortex model vm.

getΓ(b::PotentialFlowBody) -> Float64

Returns the bound circulation of the body b.

getΩ(b::PotentialFlowBody) -> Float64

Returns the rotational velocity of the body b.

impulse(vm)

Computes the impulse associated with the current state vortices and bodies in the vortex model vm. Note that newly inserted vortices should have their strengths set prior to calling this function to be included in the impulse calculation.

impulse(vm, wphysical, fphysical)

Computes the impulse associated with the vorticity wphysical, the bound vortex sheet strength fphysical, and the velocities of the discrete points of the bodies in vm.

impulse(sol, vm)

Computes the impulse associated with the body motions in the vortex model vm and the vortex sheet strength in sol. Note that newly inserted vortices should have their strengths set prior to calling this function to be included in the impulse calculation.

pushvortices!(vm, newvortices)

Adds newvortices to the existing vortices in the vortex model vm.

setU(
    b::PotentialFlowBody,
    U::Tuple{Float64, Float64}
) -> Tuple{Float64, Float64}

Sets the linear velocity of the body b to U.

setU∞(vm, U∞)

Sets the uniform flow of the vortex model vm to U∞.

setvortexpositions!(vm, X)

Sets the positions of the vortices in the vortex model vm to the provided X.

setvortexstrengths!(vm, Γ)
setvortexstrengths!(vm, Γ, idx)

Sets the strenghts of the vortices in the vortex model vm to the provided Γ. Indices can be provided in idx to specify the indices of the vortices whose strengths have to be set, in which case the length of Γ must be the same as the number of indices.

setvortices!(vm, newvortices)

Replaces the vortices of the vortex model vm by a copy of newvortices.

setΓ(b::PotentialFlowBody, Γ::Float64) -> Float64

Sets the bound circulation of the body b to Γ.

setΩ(b::PotentialFlowBody, Ω::Float64) -> Float64

Sets the rotational velocity of the body b to Ω.

solve!(sol, vm)

Solves the saddle point system associated with the vortex model vm and stores the solution in sol. If the vortex model contains bodies with regularized edges and a number of vortices which is greater than or equal to the number of regularized edges, the returned solution contains the computed strengths of the last N vortices in vm, with N the number of regularized edges.

solve(vm)

Solves the saddle point system associated with the vortex model vm and returns the solution. If the vortex model contains bodies with regularized edges and a number of vortices which is greater than or equal to the number of regularized edges, the returned solution contains the computed strengths of the last N vortices in vm, with N the number of regularized edges.

streamfunction!(ψ, vm)

Computes the stream function field ψ on the physical grid for the potential flow associated with the current state of the vortex model vm.

streamfunction(vm)

Computes and returns the stream function field on the physical grid for the potential flow associated with the current state of the vortex model vm.

subtractcirculation!(
    b::AbstractVector{PotentialFlowBody},
    δΓ_vec::AbstractVector
)

Returns the indices in the global set of surface point data of all regularized points in b.

vortexvelocities!(Ẋ_vortices, vm, ψ)

Computes and stores in Ẋ_vortices the flow velocity, associated with the discrete vector potential field ψ, as VectorData at the locations of the vortices stored in the vortex model vm.

vortexvelocities!(vm)

Returns the flow velocity as VectorData at the locations of the vortices stored in the vortex model vm, accounting for bodies in vm. If the vm has Ne regularized edges and vortices, the strengths of the last Ne vortices will be computed and set in vm and the circulation of the shedded vortices will be subtracted from the bound circulation of each body.

vorticity!(wphysical, vm; onlybulk)

Computes the vorticity field w associated with the vortices stored in the vortex model vm on the physical grid. If the extra boolean keyword onlybulk is set to true, the function ignores the vorticity from the last Ne vortices in vm.

vorticity(vm)

Computes the vorticity field associated with the vortices stored in the vortex model vm on the physical grid.