## 155 Reputation

11 years, 176 days

## unable to get the desire plot...

Maple

Dear Maple users Help me to  get the desire graph for this codes.

restart:
with(plots):
with(IntegrationTools):
h:=z->piecewise( z<=d+1,   1,
z<=d+4,   1-(delta/(2))(1 + cos(2(Pi)*(z - 1 - 1/2))),                                                           z<=d+6,   1 ):
w0:=(-c*h(z)^2/4)+(3/64)(b*c-4*a)*h(z)^4+(19/2304)*b(b-4*a)*h(z)^6:
w1:=(c/4)+(1/16)*(4*a-b*c)*h(z)^2:
w2:=(1/256)(4(b*c-4*a)-b*h(z)^2):
w3:=(1/2304)b(b-4*a):
a:=(x4*S*Gr)*sin(alpha)/(4*x1*x5):
b:=(1/Da)+(x3*M/(x1*(1+m^2))):
c:=(1/x1)*Dp:
Dp:=96*x1/((6-b*h(z)^2)h(z)^4)(F+(a*h(z)/24)-((11/6144)b(b-4*a)*h(z)^8)):
x1:=1/((1-phi1)^2.5*(1-phi2)^2.5):
x2:=(1-phi2)((1-phi1)+phi1*Rs1/Rf)+phi2(Rs2/Rf):
x3:=(shnf)/(sf):
x4:=(1-phi2)((1-phi1)+phi1(RBs1)/(RBf))+phi2*((RBs2)/(RBf)):
x5:=khnf/kf:
shnf:=sbf*((ss2+2*sbf-2*phi2*(sbf-ss2))/(ss2+2*sbf+phi2*(sbf-ss2))):
sbf:=sf*((ss1+2*sf-2*phi1*(sf-ss1))/(ss1+2*sf+phi1*(sf-ss1))):
khnf:=kbf*((ks2+2*kbf-2*phi2*(kbf-ks2))/(ks2+2*kbf+phi2*(kbf-ks2))):
kbf:=kf*((ks1+2*kf-2*phi1*(kf-ks1))/(ks1+2*kf+phi1*(kf-ks1))):
RBs1:=(8933*16.7*10^6):
RBf:=(1063*1.8*10^6):
RBs2:=6320*18*10^6:
kf:=0.492:
sbf:=6.67*10^(-1): ss2:=2.7*10^(-8):
sf:=6.67*10^(-1):ss1:=59.6*10^(6):
ks2:=76.5:kf:=0.492: ks1:=401:
phi1:=0.01: phi2:=0.02:alpha:=Pi/4:m:=0.5:Da:=0.1:Gr:=5:delta:=1:S:=0.5:  d:=1:

W1:=w0+w1*r^2+w2*r^4+w3*r^6:

by varing M =2,5,7 and r varies from 0 to 1 i want this type of graphs.  please see the sample graphs

## Piecewise function defining...

Maple

Dear maple user,for defining the piecewise function please rectify this

h:z-> piecewise(do+Lo<z<do+4*Lo+0.3,    1-cos(2*pi*(z-L), other wise 1)

## Error in system of Pdes equations ...

Maple 2022

Dear Maple   help me to  to plot the graph please see and rectify.  thanks in advance

i am attaching the codes

inf:=5:
pdes:= R(X,R,t)*diff(U(X,R,t),X)+U(X,R,t)*diff(R(X,R,t),X)+R(X,R,t)*diff(V(X,R,t),R)+V(X,R,t),
diff(U(X,R,t),t)+U(X,R,t)*diff(U(X,R,t),X)+V(X,R,t)*diff(U(X,R,t),R)=Gr*T(X,R,t)+Gc*C(X,R,t)+(1/R(X,R,t))*diff(R*diff(U(X,R,t),R),R),
diff(T(X,R,t),t)+U(X,R,t)*diff(T(X,R,t),X)+V(X,R,t)*diff(T(X,R,t),R)+(1/(Pr*R(X,R,t)))*diff(R*diff(T(X,R,t),R),R),diff(C(X,R,t),t)+U* diff(C(X,R,t),X)+V(X,R,t)*diff(C(X,R,t),R)+(1/(Sc*R(X,R,t)))*diff(R*diff(C(X,R,t),R),R):
conds:= U(X,R,0)=0, V(X,R,0)=0, T(X,R,0)=0,  C(X,R,0)=0,
U(X,1,t)=1, V(X,1,t)=0, T(X,1,t)=1,  C(X,1,t)=1,                                                                          U(0,R,t)=0, T(0,R,t)=0, C(0,R,t)=0,
U(X,int,t)=0,T(X,int,t)=0,C(X,int,t)=0:
pars:= { Gr=5, Gc=10,Sc=2.0}

pars := {Gc = 10, Gr = 5, Sc = 2.0}

PrVals:=[0.71, 1.00, 1.25, 2.00]:
colors:=[red, green, blue, black]:
for j from 1 to numelems(PrVals) do
pars1:=`union`( pars, {Pr=PrVals[j]}):
pdSol:= pdsolve( eval([pdes], pars1),
eval([conds], pars1),
numeric
);
plt[j]:=pdSol:-plot( U(X,R,t),X=1, t=2, R=0..inf, numpoints=200, color=colors[j]);
od:
plots:-display( [seq(plt[j], j=1..numelems(PrVals))]);

## How to solve the difference scheme solv...

Maple

Dear maple users,

i want to solve these 4 difference scheme equations to calculate the values of U,V,C,T and plot the graphs i verse U by fixing the values

i:=1,Sc:=2,Gr:=5,Gc:=10,DX:=0.02;DR:=0.2,Dt:=:=0.01:m:=7.44,7.88 where ,j=0..5;

eq1[i,j,m]:=(1/(4*DX))*(U[i, j-1,m+1]-U[i-1, j-1,m+1]+U[i,j,m+1]-U[i-1, j,m+1]- U[i-1, j-1,m]+U[i, j,m]-U[i-1, j,m])+(1/(2*DR))*(V[i, j,m+1]-V[i, j-1,m+1]+V[i, j,m]-V[i, j-1,m])+(1/(1+(j-1)*DR))*(V[i, j,m+1]):

eq2[i,j,m]:=(1/Dt)*(U[i, j,m+1]-U[i, j,m])+(U[i, j,m]/(2*DX))*(U[i, j,m+1]-U[i-1, j,m+1]+U[i, j,m]-U[i-1, j,m])+(V[i, j,m]/(4*DR))*(U[i, j+1,m+1]-U[i, j-1,m+1]+U[i, j+1,m]-U[i, j-1,m])=(Gr/2)*(T[i, j,m+1]+T[i, j,m])+(Gc/2)*(C[i, j,m+1]+C[i, j,m])+(1/(2*(DR)^2))*(U[i, j-1,m+1]-2*U[i, j,m+1]+U[i, j+1,m+1]+U[i, j-1,m]-2*U[i, j,m]+U[i, j+1,m])+(1/(4*DR*(1+(j-1)*DR)))*(U[i, j+1,m+1]-U[i, j-1,m+1]+U[i, j+1,m]-U[i, j-1,m]):

eq3[i,j,m]:=(1/Dt)*(T[i, j,m+1]-T[i, j,m])+(U[i, j,m]/(2*DX))*(T[i, j,m+1]-T[i-1, j,m+1]+T[i, j,m]-T[i-1, j,m])+(V[i, j,m]/(4*DR))*(T[i, j-1,m+1]-T[i, j-1,m+1]+T[i, j+1,m]-T[i, j-1,m])=(1/(2*Pr*(DR)^2))*(T[i, j-1,m+1]-2*T[i, j,m+1]+T[i, j+1,m+1]+T[i, j-1,m]-2*T[i, j,m]+T[i, j+1,m])+(1/(4*Pr*DR*(1+(j-1)*DR)))*(T[i, j+1,m+1]-T[i, j-1,m+1]+T[i, j+1,m]-T[i, j-1,m]):
eq4[i,j,m]:=(1/Dt)*(C[i, j,m+1]-C[i, j,m])+(U[i, j,m]/(2*DX))*(C[i, j,m+1]-C[i-1, j,m+1]+C[i, j,m]-C[i-1, j,m])+(V[i, j,m]/(4*DR))*(C[i, j+1,m+1]-C[i, j-1,m+1]+C[i, j+1,m]-C[i, j-1,m])=(1/(2*Sc*(DR)^2))*(C[i, j-1,m+1]-2*C[i, j,m+1]+C[i, j+1,m+1]+C[i, j-1,m]-2*C[i, j,m]+C[i, j+1,m])+(1/(4*Sc*DR*(1+(j-1)*DR)))*(C[i, j+1,m+1]-C[i, j-1,m+1]+C[i, j+1,m]-C[i, j-1,m]):

## System of pdes analyically unable to ...

Maple

Dear maple  whats wrong with the code that  maple cannot solve analytically pdes with initial conditions

restart:
sys:={diff(u(x, t), t)=0,diff(v(x, t), t)=0};
IBC:={u(x, 0)=exp((x))/(1+exp((0.5*x)))^2,v(x, 0)=1/(1+exp((0.5*x)))};
pdsolve(sys);
pdsolve(sys,IBC);

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