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Add function getdim for easy dimensionalizing of coefficients #24

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Add function getdim for easy dimensionalizing of coefficients #24

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76 changes: 75 additions & 1 deletion src/CCBlade.jl
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Original file line number Diff line number Diff line change
Expand Up @@ -18,7 +18,7 @@ using ImplicitAD

export Rotor, Section, OperatingPoint, Outputs
export simple_op, windturbine_op
export solve, thrusttorque, nondim
export solve, thrusttorque, nondim, getdim


include("airfoils.jl") # all the code related to airfoil data
Expand Down Expand Up @@ -738,5 +738,79 @@ function nondim(T, Q, Vhub, Omega, rho, rotor, rotortype)

end

"""
getdim(CT, CQ, Vhub, Omega, rho, rotor, rotortype)

Dimensionalize the outputs.

**Arguments**
- `CT::Float64`: thrust coefficient
- `CQ::Float64`: torque coefficient
- `Vhub::Float64`: hub speed used in turbine normalization (m/s)
- `Omega::Float64`: rotation speed used in propeller normalization (rad/s)
- `rho::Float64`: air density (kg/m^3)
- `rotor::Rotor`: rotor object
- `rotortype::String`: normalization type

**Returns**

`if rotortype == "windturbine"`
- `P::Float64`: power
- `T::Float64`: thrust
- `Q::Float64`: torque

`if rotortype == "propeller"`
- `eff::Float64`: efficiency
- `T::Float64`: thrust
- `Q::Float64`: torque

`if rotortype == "helicopter"`
- `FM::Float64`: figure of merit
- `T::Float64`: thrust
- `Q or P::Float64`: torque/power (they are identical)
"""
function getdim(CT, CQ, Vhub, Omega, rho, rotor, rotortype)

Rp = rotor.Rtip*cos(rotor.precone)

if rotortype == "windturbine" # wind turbine normalizations

q = 0.5 * rho * Vhub^2
A = pi * Rp^2

Q = (q * Rp * A) * CQ
P = Q * Omega
T = (q * A) * CT

return P, T, Q

elseif rotortype == "propeller"

n = Omega/(2*pi)
Dp = 2*Rp

T = (rho * n^2 * Dp^4) * CT
Q = (rho * n^2 * Dp^5) * CQ
P = Q * Omega
if T < 0
eff = 0.0 # creating drag not thrust
else
eff = T*Vhub/P
end

return eff, T, Q

elseif rotortype == "helicopter"

A = pi * Rp^2

T = (rho * A * (Omega*Rp)^2) * CT
Q = (rho * A * (Omega*Rp)^2 * Rp) * CQ # note that CQ = CP
FM = CT^(3.0/2)/(sqrt(2)*CQ)

return FM, T, Q
end

end

end # module
33 changes: 30 additions & 3 deletions test/runtests.jl
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Original file line number Diff line number Diff line change
Expand Up @@ -189,11 +189,15 @@ out = solve.(Ref(rotor_no_F), sections, op)
T = sum(out.Np*(r[2]-r[1]))*B
Q = sum(r.*out.Tp*(r[2]-r[1]))*B
eff, CT, CQ = nondim(T, Q, Vinf, Omega, rho, rotor, "propeller")
eff1, T1, Q1 = getdim(CT, CQ, Vinf, Omega, rho, rotor, "propeller")


@test isapprox(CT, 0.056110238632657, atol=1e-7)
@test isapprox(CQ, 0.004337202960642, atol=1e-8)
@test isapprox(eff, 0.735350632777002, atol=1e-6)
@test isapprox(T1, T, atol=1e-6)
@test isapprox(Q1, Q, atol=1e-6)
@test isapprox(eff1, eff, atol=1e-6)


# ---------------------------------------------
Expand Down Expand Up @@ -351,6 +355,13 @@ ntsr = 20 # number of tip-speed ratios
tsrvec = range(2, stop=15, length=ntsr)
cpvec = zeros(ntsr) # initialize arrays
ctvec = zeros(ntsr)
cqvec = zeros(ntsr)
Pvec = zeros(ntsr)
Tvec = zeros(ntsr)
Qvec = zeros(ntsr)
Pvec1 = zeros(ntsr)
Tvec1 = zeros(ntsr)
Qvec1 = zeros(ntsr)

azangles = pi/180*[0.0, 90.0, 180.0, 270.0]

Expand All @@ -360,8 +371,10 @@ for i = 1:ntsr
ops = windturbine_op.(Vinf, Omega, pitch, r, precone, yaw, tilt, azangles', hubHt, shearExp, rho)
outs = solve.(Ref(rotor), sections, ops)
T, Q = thrusttorque(rotor, sections, outs)
Pvec[i], Tvec[i], Qvec[i] = Q*Omega, T, Q

cpvec[i], ctvec[i], _ = nondim(T, Q, Vinf, Omega, rho, rotor, "windturbine")
cpvec[i], ctvec[i], cqvec[i] = nondim(T, Q, Vinf, Omega, rho, rotor, "windturbine")
Pvec1[i], Tvec1[i], Qvec1[i] = getdim(ctvec[i], cqvec[i], Vinf, Omega, rho, rotor, "windturbine")
end

cpvec_test = [0.02350364982213779, 0.07009444382724848, 0.1389142676582008, 0.21796006904596332, 0.30793648085907793, 0.39220377428841097, 0.4358126426438294, 0.45890373500510734, 0.4692861367774551, 0.4675297063104674, 0.45763823228659106, 0.442190136700292, 0.4231819091376136, 0.4013611296914438, 0.37661228050658546, 0.3487266071360946, 0.31761016554953614, 0.2831513131286119, 0.24519843834864297, 0.20383577257448457]
Expand All @@ -370,6 +383,9 @@ ctvec_test = [0.12346062066554207, 0.19135957414241508, 0.2753773487370145, 0.36
for i = 1:ntsr
@test isapprox(cpvec[i], cpvec_test[i], atol=1e-3)
@test isapprox(ctvec[i], ctvec_test[i], atol=1e-3)
@test isapprox(Pvec1[i], Pvec[i], atol=1e-3)
@test isapprox(Tvec1[i], Tvec[i], atol=1e-3)
@test isapprox(Qvec1[i], Qvec[i], atol=1e-3)
end


Expand Down Expand Up @@ -488,14 +504,22 @@ pitch = range(1e-4, 20*pi/180, length=nP)

CT = zeros(nP)
CQ = zeros(nP)
FM = zeros(nP)
Tvec = zeros(nP)
Qvec = zeros(nP)
T1 = zeros(nP)
Q1 = zeros(nP)
FM1 = zeros(nP)


for i = 1:nP

op = simple_op.(Vinf, Omega, r, rho, pitch=pitch[i])
outputs = solve.(Ref(rotor), sections, op)
T, Q = thrusttorque(rotor, sections, outputs)
_, CT[i], CQ[i] = nondim(T, Q, Vinf, Omega, rho, rotor, "helicopter")
Tvec[i], Qvec[i] = T, Q
FM[i], CT[i], CQ[i] = nondim(T, Q, Vinf, Omega, rho, rotor, "helicopter")
FM1[i], T1[i], Q1[i] = getdim(CT[i], CQ[i], Vinf, Omega, rho, rotor, "helicopter")
end

# these are not directly from the experimental data, but have been compared to the experimental data and compare favorably.
Expand All @@ -506,6 +530,9 @@ CQcomp = [0.000226663607327854, 0.0002270862930229147, 0.0002292742856722754, 0.
for i = 1:nP
@test isapprox(CT[i], CTcomp[i], atol=1e-4)
@test isapprox(CQ[i], CQcomp[i], atol=1e-4)
@test isapprox(T1[i], Tvec[i], atol=1e-4)
@test isapprox(Q1[i], Qvec[i], atol=1e-4)
@test isapprox(FM1[i], FM[i], atol=1e-4)
end

end
Expand Down Expand Up @@ -816,4 +843,4 @@ end
@test checkstability()


end
end