[Peter023]

Hello all:

please, could anyone help me with the, so called, Drift Flux Model which is, among another tools for the evaluation of the particle transport and deposition onto different surfaces, a possible solution of the particle transport phenomena. Unfortunately, the original model and other improved models depicted in the literature are not clearly explained and I have a real problem with their transformation into the UDF.
the literature, for example, is :
http://www.sciencedirect.com/science...63e83283d44ef9

or:

http://www.sciencedirect.com/science...1128c844815001

If somebody has the solution or some idea or source code, please let me know

Thanks in advance.

Pete.

[Peter023]

As a source I'm trying to use this:

real vs = (9.81 * (1400.0 - C_R(c,t)) * dp * dp) / (18.0 * C_MU_EFF(c,t));
source = (vs + C_W(c,t)) * C_UDSI(c,t,0);
dS[eqn] = 0.0;

As a diffusivity term (DEFINE_DIFFUSIVITY):
D = (Kb * 300.0 * Cc(dp, Lambda)) / (3.0 * 3.14 * C_MU_EFF(cell,thread) * dp); // Brownian diffusivity
diffu_particle = D + C_MU_EFF(cell,thread);

and deposition onto surfaces:

DEFINE_PROFILE(deposition_floor, thread, i)
{
face_t f;
Thread *t;
cell_t c;
real jay_a = 0.0, jay_b = 0.0;
real vs = 0.0; // Settling velocity
real v_dd = 0.0; // Dep. velocity, downward horiz. surface
real D = 0.0; // Brownian diffusivity

begin_f_loop(f,thread)
{
c = F_C0(f,thread);
t = THREAD_T0(thread);

vs = (9.81 * (1400.0 - C_R(c,t)) * dp * dp) / (18.0 * C_MU_EFF(c,t)); // Settling vel.

if (selector)
{
v_dd = vs / (exp(vs * integral / frict_vel) - 1.0); // Deposition vel.
jay_b = sign * (v_dd * C_UDSI(c,t,0));
F_PROFILE(f,thread,i) = jay_b;
}else
{
D = (Kb * 300.0 * Cc(dp, Lambda)) / (3.0 * 3.14 * C_MU_EFF(c,t) * dp); // Brownian diffusivity
jay_a = sign * ((D + C_MU_T(c,t)) * C_UDSI_G(c,t,0)[2]) + vs * C_UDSI(c,t,0);
F_PROFILE(f,thread,i) = jay_a;
}
}
end_f_loop(f,thread)
//Message("Floor Data :: Vs = %g, v_dd = %g, D = %g, Jay_a = %g, Jay_b = %g\n", vs,v_dd,D,jay_a,jay_b);
}

[laoji]

Dear Peter：
have you solved your drift-flux problem ??
I am doing the modeling about particle transport using the UDS . But there are some problem with the advection term . And I don't know how to deal with the particle deposition model . Could you give me some advise ??

[qin chunqiu]

integral and frict_vel are not defined