Hello everyone,

im new here and i've nerly no expertise in pd-equations. I was trying to solve this pd-system with the following-code:

with(plots);
with(DEtools);
with(PDEtools);

`εg` := .4;
`εs` := .6;
mg := 1;
mgs := 1;
`ρg` := 1.2;
`ρs` := 1100;
cpg := 1006;
cps := 880;
cpwa := 1920;
`αGS` := 20;
as := 800;
h_ads := 2700000;
pdgl1 := `εg`*`ρg`*(diff(xG(t, z), t)) = -mgs-mg*(diff(xG(t, z), z));
pdgl2 := `εs`*`ρs`*(diff(xS(t, z), t)) = mgs;
pdgl3 := `εg`*`ρg`*(cpg+xG(t, z)*cpwa)*(diff(TG(t, z), t)) = -mg*(cpg+xG(t, z)*cpwa)*(diff(TG(t, z), z))+`αGS`*as*(TS(t, z)-TG(t, z));
pdgl4 := `εs`*`ρs`*(diff(TS(t, z), t))*(cps+xS(t, z)*cpwa) = mgs*h_ads-`αGS`*as*(TS(t, z)-TG(t, z));
Init := {TG(0, z) = 401.15, TG(t, 0) = 401.15, TS(0, z) = 293.15, TS(t, 0) = 293.15, xG(0, z) = 0.5e-1, xG(t, 0) = 0.5e-1, xS(0, z) = .33, xS(t, 0) = .33};
sol := pdsolve({pdgl1, pdgl2, pdgl3, pdgl4}, Init, type = numeric, range = 0 .. 1, time = t);

Error, (in pdsolve/numeric/par_hyp) Incorrect number of boundary conditions, expected 2, got 4

When i change initial conditions to 4 it says he expected 2 and when i put 2 it says he expected 4.

Can anyone tell me where my misstake is or in what direction i have to look for an answer.

Thanks from before.

Can