Add sandbox for testing P3 scheme

p3_sandbox/Project.toml

@@ -0,0 +1,12 @@
+[deps]
+CLIMAParameters = "6eacf6c3-8458-43b9-ae03-caf5306d3d53"
+CairoMakie = "13f3f980-e62b-5c42-98c6-ff1f3baf88f0"
+CloudMicrophysics = "6a9e3e04-43cd-43ba-94b9-e8782df3c71b"
+KernelAbstractions = "63c18a36-062a-441e-b654-da1e3ab1ce7c"
+OrdinaryDiffEq = "1dea7af3-3e70-54e6-95c3-0bf5283fa5ed"
+RootSolvers = "7181ea78-2dcb-4de3-ab41-2b8ab5a31e74"
+Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
+Thermodynamics = "b60c26fb-14c3-4610-9d3e-2d17fe7ff00c"
+
+[compat]
+CLIMAParameters = "0.8"

p3_sandbox/p3_sandbox.jl

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+import OrdinaryDiffEq as ODE
+
+import CloudMicrophysics.Parameters as CMP
+import CloudMicrophysics.P3Scheme as P3
+import CloudMicrophysics.HetIceNucleation as CMI_het
+import CloudMicrophysics.Common as CMO
+import Thermodynamics as TD
+
+"""
+    ODE problem definitions
+"""
+function p3_sandbox(dY, Y, p, t)
+
+    # Numerical precision used in the simulation
+    FT = eltype(Y)
+    (; const_dt, tps, T, pₐ, qᵥ, qₗ, Nₗ, rₗ, aero_type) = p
+    p3 = CMP.ParametersP3(FT)
+
+    # Our state vector
+    Nᵢ = Y[1]      # Ice number concentration
+    qᵢ = Y[2]      # Ice mixing ratio
+    qᵣ = Y[3]      # Rime mass mixing ratio
+    Bᵣ = Y[4]      # Rime volume
+
+    F_r = qᵣ / qᵢ
+    ρ_r = ifelse(Bᵣ == 0, FT(0), qᵣ / Bᵣ)
+    q = TD.PhasePartition(qᵥ + qₗ + qᵢ, qₗ, qᵢ)
+
+    Rₐ = TD.gas_constant_air(tps, TD.PhasePartition(qᵥ))
+    R_v = TD.Parameters.R_v(tps)
+    e = qᵥ * pₐ * R_v / Rₐ
+
+    a_w = CMO.a_w_eT(tps, e, T)
+    a_w_ice = CMO.a_w_ice(tps, T)
+    Δa_w = a_w - a_w_ice
+    J_immersion = CMI_het.ABIFM_J(aero_type, Δa_w)
+    dNᵢ_dt = J_immersion * Nₗ * 4 * π * rₗ^2
+    println("J = ", J_immersion)
+
+    sol = P3.thresholds(p3, ρ_r, F_r)
+    println(" ")
+    println("D_cr = ", sol.D_cr)
+    println("D_gr = ", sol.D_gr)
+    println("ρ_g =  ", sol.ρ_g)
+    println("ρ_dr = ", sol.ρ_d)
+
+    # TODO - compute the corresponding N0 and λ
+    # TODO - add ice nucleation source terms
+    # TODO - allow for zero rimed mass and volume
+
+    # Set tendencies
+    dY[1] = dNᵢ_dt       # ice number concentration
+    dY[2] = FT(0)        # ice mixing ratio
+    dY[3] = FT(0)        # rime mixing ratio
+    dY[4] = FT(0)        # rime volume
+end
+
+FT = Float64
+
+const_dt = 1.0
+t_0 = 0
+t_end = 2
+
+tps = TD.Parameters.ThermodynamicsParameters(FT) # thermodynamics free parameters
+wps = CMP.WaterProperties(FT)
+
+T = FT(251)
+pₐ = FT(800 * 1e2)  # air pressure
+ρₗ = wps.ρw
+Nₗ = FT(500 * 1e3)   # number of cloud droplets
+rₗ = FT(1e-6)        # radius of dropletes
+qᵥ = FT(8.1e-4)     # mixing ratio of water vapor
+qₗ = Nₗ * 4 / 3 * π * rₗ^3 * ρₗ / 1.2 # 1.2 should be ρₐ
+aero_type = CMP.Illite(FT)
+
+p = (; const_dt, tps, T, pₐ, qᵥ, qₗ, Nₗ, rₗ, aero_type)
+
+Nᵢ_0 = 100 * 1e6
+qᵢ_0 = 1e-3
+qᵣ_0 = 1e-4
+Bᵣ_0 = 1 / 200 * 1e-4
+
+IC = [FT(Nᵢ_0), FT(qᵢ_0), FT(qᵣ_0), FT(Bᵣ_0)]
+
+problem = ODE.ODEProblem(p3_sandbox, IC, (FT(t_0), FT(t_end)), p)
+sol = ODE.solve(
+    problem,
+    ODE.Euler(),
+    dt = const_dt,
+    reltol = 10 * eps(FT),
+    abstol = 10 * eps(FT),
+)
+
+println("number of ice crystals = ", sol[1,:])