static void Main()
{
const int tsteps = 1; // time steps
const float physlength = 10.0f; // phys length
const int xsteps = 40; // space nodes quantity for BGK
const int nvlc = 60; // velocity nodes quantity for BGK
//--hybrid Left and Right BGK segments
float[,] fleft = new float[xsteps, nvlc];
float[,] fright = new float[xsteps, nvlc];
const float Kn = 1.0f;
const float vw = 0.024f; // distance between velocities
float totmass = 0f; // total mass
// initial boundary conditions
float u1 = 0.08f;
float T1 = 0.64f;
float rho1 = 1.0f / BGK_1d._n_eq_check_dens(T1, u1, vw, nvlc);
float u2 = -0.055f;
float T2 = 0.64f;
float rho2 = 1.0f / BGK_1d._n_eq_check_dens(T2, u2, vw, nvlc);
//--BGK boundaries, time = 0;
for (int k = 0; k < nvlc; ++k)
{
//--hybrid
fleft[0, k] = BGK_1d._n_eq(T1, rho1, u1, vw, nvlc, k);
fright[xsteps - 1, k] = BGK_1d._n_eq(T2, rho2, u2, vw, nvlc, k);
}
const int nlattice = 161; // space nodes quantity for lattice
float[,] flattice = new float[nlattice, 6];
//--hybrid declaration
BGK_1d bgk_left, bgk_right;
D1Q6 lattice;
float m0 = 0, m1 = 0, m2 = 0;
const float w0 = 0.3234f;
const float w1 = 0.1463f;
const float w2 = 0.0303f;
/*
* {{0.3234 * 1,0.1463 * 1,0.0303 * 1},
* {0.3234 * 0.5,0.1463 * 1,0.0303 * 3},
* {0.3234 * 0.25,0.1463 * 1,0.0303 * 9}}^-1 =
* {{7.42115, -9.89487, 2.47372},
* {-10.2529, 23.9234, -6.83527},
* {3.30033, -9.90099, 6.60066}}
* wolframalpha.com */
const float a11 = 7.42115f;
const float a12 = -9.89487f;
const float a13 = 2.47372f;
const float a21 = -10.2529f;
const float a22 = 23.9234f;
const float a23 = -6.83527f;
const float a31 = 3.30033f;
const float a32 = -9.90099f;
const float a33 = 6.60066f;
for (int i = 1; i < nlattice - 1; ++i)
{
flattice[i, 0] = D1Q6._n_eq_k(1.0f, u1, 0);
flattice[i, 1] = D1Q6._n_eq_k(1.0f, u1, 1);
flattice[i, 2] = D1Q6._n_eq_k(1.0f, u1, 2);
flattice[i, 3] = D1Q6._n_eq_k(1.0f, u1, 3);
flattice[i, 4] = D1Q6._n_eq_k(1.0f, u1, 4);
flattice[i, 5] = D1Q6._n_eq_k(1.0f, u1, 5);
}
for (int time = 0; time < tsteps; ++time)
{
bgk_left = new BGK_1d(fleft, Kn, vw, physlength);
bgk_right = new BGK_1d(fright, Kn, vw, physlength);
//--hybrid, solve BGK for t = 1.0
fleft = bgk_left.Solve(1.0f);
fright = bgk_right.Solve(1.0f);
m0 = m1 = m2 = 0;
for (int i = nvlc / 2; i < nvlc; ++i)
{
m0 += fleft[xsteps - 1, i];
m1 += fleft[xsteps - 1, i] * (vw * (i - (nvlc - 1.0f) / 2.0f));
m2 += fleft[xsteps - 1, i] * (vw * (i - (nvlc - 1.0f) / 2.0f))
* (vw * (i - (nvlc - 1.0f) / 2.0f));
}
// m0 *= 1.0f; m1 *= vw; m2 *= vw;
//--TODO: set LBE condition (flattice[,] = F(flattice, fleft, fright) )
flattice[0, 3] = a11 * m0 + a12 * m1 + a13 * m2;
flattice[0, 4] = a21 * m0 + a22 * m1 + a23 * m2;
flattice[0, 5] = a31 * m0 + a32 * m1 + a33 * m2;
m0 = m1 = m2 = 0;
for (int i = 0; i < nvlc / 2; ++i)
{
m0 += fright[0, i];
m1 -= fright[0, i] * (vw * (i - (nvlc - 1.0f) / 2.0f));
m2 += fright[0, i] * (vw * (i - (nvlc - 1.0f) / 2.0f))
* (vw * (i - (nvlc - 1.0f) / 2.0f));
}
// m0 *= 1.0; m1 *= vw; m2 *= vw;
//--TODO: set LBE condition (flattice[,] = F(flattice, fleft, fright) )
flattice[nlattice - 1, 2] = a11 * m0 + a12 * m1 + a13 * m2;
flattice[nlattice - 1, 1] = a21 * m0 + a22 * m1 + a23 * m2;
flattice[nlattice - 1, 0] = a31 * m0 + a32 * m1 + a33 * m2;
lattice = new D1Q6(flattice, 1.0f);
flattice = lattice.Solve();
//--TODO: set new BGK internal boundary data fleft, fright = g(fleft(right), flattice)
//--левая точка сращивания
m0 = w0 * 1.0f * flattice[0, 2] + w1 * flattice[0, 1] + w2 * 1.0f * flattice[0, 0];
m1 = -w0 * 0.5f * flattice[0, 2] - w1 * flattice[0, 1] - w2 * 3.0f * flattice[0, 0];
m2 = w0 * 0.25f * flattice[0, 2] + w1 * flattice[0, 1] + w2 * 9.0f * flattice[0, 0];
for (int i = 0; i < nvlc / 2; ++i)
{
fleft[xsteps - 1, i] = vw * 1.0f / (float)Math.Sqrt(2.0 * Math.PI * 1.0f)
* (float)Math.Exp(-
((i - (nvlc - 1.0) / 2.0) * vw) *
((i - (nvlc - 1.0) / 2.0) * vw) / (2.0))
* (float)(m0 + m1 * (i - (nvlc - 1.0) / 2.0) * vw +
(m1 - m0) *
(((i - (nvlc - 1.0) / 2.0) * vw) *
((i - (nvlc - 1.0) / 2.0) * vw) - 1.0)
);
}
//--правая точка сращивания
m0 = w0 * 1.0f * flattice[nlattice - 1, 3] + w1 * flattice[nlattice - 1, 4] + w2 * 1.0f * flattice[nlattice - 1, 5];
m1 = w0 * 0.5f * flattice[nlattice - 1, 3] + w1 * flattice[nlattice - 1, 4] + w2 * 3.0f * flattice[nlattice - 1, 5];
m2 = w0 * 0.25f * flattice[nlattice - 1, 3] + w1 * flattice[nlattice - 1, 4] + w2 * 9.0f * flattice[nlattice - 1, 5];
for (int i = nvlc / 2; i < nvlc; ++i)
{
fright[0, i] = vw * 1.0f / (float)Math.Sqrt(2.0 * Math.PI * 1.0f)
* (float)Math.Exp(-
((i - (nvlc - 1.0) / 2.0) * vw) *
((i - (nvlc - 1.0) / 2.0) * vw) / (2.0))
* (float)(m0 + m1 * (i - (nvlc - 1.0) / 2.0) * vw +
(m1 - m0) *
(((i - (nvlc - 1.0) / 2.0) * vw) *
((i - (nvlc - 1.0) / 2.0) * vw) - 1.0)
);
}
}
//--results
bgk_left = new BGK_1d(fleft, Kn, vw, physlength);
bgk_right = new BGK_1d(fright, Kn, vw, physlength);
bgk_left.Solve_one_step();
bgk_right.Solve_one_step();
float[] P = bgk_left.P();
float[] U = bgk_left.U();
float[] T = bgk_left.Temperatures();
totmass = 0; //--diagnostics of the left BGK area
for (int i = 0; i < xsteps; i++)
{
Console.WriteLine(i / (xsteps - 1.0f) + " " + P[i] + " " + U[i] + " " + T[i] + " " + P[i] * U[i]);
totmass = totmass + P[i];
}
//--diagnostics lattice
for (int i = 0; i < nlattice; i++)
{
Console.WriteLine(flattice[i, 0] + " " + flattice[i, 1] + " " + flattice[i, 2] +
" " + flattice[i, 3] + " " + flattice[i, 4] + " " + flattice[i, 5] + " x" + i * 0.5);
}
Console.WriteLine("mass=" + totmass);
Console.ReadLine();
// Application.EnableVisualStyles();
// Application.SetCompatibleTextRenderingDefault(false);
// Application.Run(new Form1());
}
static void Main()
{
const int tsteps = 10000; // time steps
// internal condition
float u0 = 0.48f;
// initial boundary conditions, Temperature = 1.
float u1 = 0.35f;
float rho1 = 1.0f;
float u2 = -0.28f;
float rho2 = 1.0f;
const int nlattice = 161; // space nodes quantity for lattice
float[,] flattice = new float[nlattice, 6];
//--hybrid declaration
D1Q6 lattice;
for (int i = 1; i < nlattice - 1; ++i)
{
flattice[i, 0] = D1Q6._n_eq_k(1.0f, u0, 0);
flattice[i, 1] = D1Q6._n_eq_k(1.0f, u0, 1);
flattice[i, 2] = D1Q6._n_eq_k(1.0f, u0, 2);
flattice[i, 3] = D1Q6._n_eq_k(1.0f, u0, 3);
flattice[i, 4] = D1Q6._n_eq_k(1.0f, u0, 4);
flattice[i, 5] = D1Q6._n_eq_k(1.0f, u0, 5);
}
for (int time = 0; time < tsteps; ++time)
{
//--TODO: set LBE condition (flattice[,] = F(flattice, fleft, fright) )
flattice[0, 3] = D1Q6._n_eq_k(rho1, u1, 3);
flattice[0, 4] = D1Q6._n_eq_k(rho1, u1, 4);
flattice[0, 5] = D1Q6._n_eq_k(rho1, u1, 5);
flattice[nlattice - 1, 2] = D1Q6._n_eq_k(rho2, u2, 2);
flattice[nlattice - 1, 1] = D1Q6._n_eq_k(rho2, u2, 1);
flattice[nlattice - 1, 0] = D1Q6._n_eq_k(rho2, u2, 0);
lattice = new D1Q6(flattice, 1.0f);
flattice = lattice.Solve();
}
//--results
//--diagnostics lattice
for (int i = 0; i < nlattice; i++)
{
float vrho = flattice[i, 4] - flattice[i, 1]
+ 0.5f * (flattice[i, 3] - flattice[i, 2])
+ 3.0f * (flattice[i, 5] - flattice[i, 0]);
float _rho = flattice[i, 0] + flattice[i, 1] +
flattice[i, 2] + flattice[i, 3] +
flattice[i, 4] + flattice[i, 5];
Console.WriteLine(flattice[i, 0] + " " + flattice[i, 1] + " " + flattice[i, 2] +
" " + flattice[i, 3] + " " + flattice[i, 4] + " " + flattice[i, 5] + " x" + i * 0.5
+ " v =" + vrho / _rho);
}
Console.ReadLine();
}