farahnaz

Dr. farahnaz farahnaz

15 Reputation

2 Badges

4 years, 13 days

MaplePrimes Activity


These are questions asked by farahnaz

hi..i have a problem for solving this nonlinear differential equationerror.mw

restart; Digite := 200; L := 100*10^(-9)

1/10000000

(1)

EQ11 := -3.000000000*10^(-8)+3.815358072*sin(3.141592654*10^7*x)+9.534375000*10^(-30)*(diff(w(x), x, x, x, x))-2.383593750*10^(-60)*(diff(w(x), x, x, x, x, x, x))-5.085000000*10^(-13)*(diff(w(x), x))*(diff(u(x), x, x))-7.627500000*10^(-13)*(diff(w(x), x))^2*(diff(w(x), x, x))-5.085000000*10^(-13)*(diff(w(x), x, x))*(diff(u(x), x))+0.2410290000e-5*(diff(w(x), x, x)):

EQ2 := 5.650000000*10^(-20)*(diff(u(x), x, x, x, x))-226000000000*(diff(u(x), x, x))-226000000000*(diff(w(x), x))*(diff(w(x), x, x)):

dsys3 := {EQ11, EQ2, u(0) = 0, u(L) = 0, w(0) = 0, w(L) = 0, (D(u))(0) = 0, (D(u))(L) = 0, ((D@@2)(w))(0) = 0, ((D@@2)(w))(L) = 0, ((D@@4)(w))(0) = 0, ((D@@4)(w))(L) = 0}; res := dsolve(dsys3, numeric, initmesh = 1024, abserr = 0.1e-4); res(0.1e-9)

res(0.1e-9)

(2)

############################################################CHANGE OF VARIABLE:::           x=y*L

bcs := {u(0) = 0, u(L) = 0, w(0) = 0, w(L) = 0, (D(u))(0) = 0, (D(u))(L) = 0, ((D@@2)(w))(0) = 0, ((D@@2)(w))(L) = 0, ((D@@4)(w))(0) = 0, ((D@@4)(w))(L) = 0}; sys := {EQ11, EQ2}; sys2 := PDEtools:-dchange({x = L*y, u(x) = g2(y), w(x) = g1(y)}, sys, [g1, g2, y]); solve(sys2, {diff(g2(y), y, y, y, y), diff(g1(y), y, y, y, y, y, y)}); bcs3 := {g1(0) = 0, g1(1) = 0, g2(0) = 0, g2(1) = 0, (D(g2))(0) = 0, (D(g2))(1) = 0, ((D@@2)(g1))(0) = 0, ((D@@2)(g1))(1) = 0, ((D@@4)(g1))(0) = 0, ((D@@4)(g1))(1) = 0}; res3 := dsolve(`union`(sys2, bcs3), numeric, maxmesh = 2024, abserr = 0.1e-4); plots:-odeplot(res3, [seq([y, (cat(g, i))(y)], i = 1 .. 2)], 0 .. 1)

Error, (in plots/odeplot) input is not a valid dsolve/numeric solution

 

``

 

Download error.mw

please help me

thanks...

 

hi

please help to me for solve this equation via pdsolve?

thanks

dsove2.mw

restart

f := 1; k := 1; h := 1

PDE := diff((diff(rho*H(rho, z), rho))/rho, rho)+diff(H(rho, z), z, z)+k^2*H(rho, z) = f

-(H(rho, z)+rho*(diff(H(rho, z), rho)))/rho^2+(2*(diff(H(rho, z), rho))+rho*(diff(diff(H(rho, z), rho), rho)))/rho+diff(diff(H(rho, z), z), z)+H(rho, z) = 1

(1)

NULL

NULL

NULL

NULL

sol3 := dsolve([PDE, (D[2](H))(rho, -h) = 0, (D[2](H))(rho, 0) = 0], H(rho, z))

NULL



Download dsove2.mw

 

 

 

hi

how i can plot 4 curve in one graph in maple??

this data is given in excel format as below

thanks

16.3.xlsx

hi .may every one help me for pdsolve this differential equations?

all initial boundary condition are zero

thanks...

pdeSol_(1).mw

 

#
# Define some parameters
#
  sigma := 10; N := 0; beta := 1; alpha := 1; PDE1 := diff(w(X, theta, t), X, X, X, X)+2*alpha^2*(diff(w(X, theta, t), theta, theta, X, X))+alpha^4*(diff(w(X, theta, t), theta, theta, theta, theta))-N*(diff(w(X, theta, t), X, X))+diff(w(X, theta, t), t, t)-beta*w(X, theta, t)-sigma = 0

10

 

0

 

1

 

1

 

diff(diff(diff(diff(w(X, theta, t), X), X), X), X)+2*(diff(diff(diff(diff(w(X, theta, t), X), X), theta), theta))+diff(diff(diff(diff(w(X, theta, t), theta), theta), theta), theta)-10+diff(diff(w(X, theta, t), t), t)-w(X, theta, t) = 0

(1)

#
# Define the PDES
#
  PDEs:= { diff(w(X, theta, t), X, X, X, X)+2*alpha^2*(diff(w(X, theta, t), theta, theta, X, X))+alpha^4*(diff(w(X, theta, t), theta, theta, theta, theta))-N*(diff(w(X, theta, t), X, X))+diff(w(X, theta, t), t, t)-beta*w(X, theta, t)-sigma = 0
   };

{diff(diff(diff(diff(w(X, theta, t), X), X), X), X)+2*(diff(diff(diff(diff(w(X, theta, t), X), X), theta), theta))+diff(diff(diff(diff(w(X, theta, t), theta), theta), theta), theta)-10+diff(diff(w(X, theta, t), t), t)-w(X, theta, t) = 0}

(2)

#
# Set of boundary conditions at x=1.
#
   bcs1:= { D[1](w)(1,theta, t) = 0,
              w(1,theta, t) = 0
         };

{w(1, theta, t) = 0, (D[1](w))(1, theta, t) = 0}

(3)

#
# Set of boundary conditions at x=0
#
  bcs2:= {    w(0,theta, t)=0,
           D[1](w)(0,theta, t)=0
         };

{w(0, theta, t) = 0, (D[1](w))(0, theta, t) = 0}

(4)

#
# Set of boundary conditions at t=0
#
  bcs3:= { w(x,theta,0)=0,
          
           D[2](w)(x,theta,0)=0 };
           

{w(x, theta, 0) = 0, (D[2](w))(x, theta, 0) = 0}

(5)

 


  pdsolve( PDEs, `union`(bcs1, bcs2, bcs3), numeric);

Error, (in pdsolve/numeric/process_PDEs) can only numerically solve PDE with two independent variables, got {X, t, theta}

 

 

 

Download pdeSol_(1).mw

hi

please help me for dsolve this equation...

error_length.mw

dsys3 := {(63/20000000)*(diff(u(x), x, x, x, x))-120000000000*(diff(u(x), x, x))-60000000000*(diff(w(x), x, x)), -2.100000000*10^(-30)*(diff(w(x), x, x, x, x, x, x))-4.860000000*10^(-14)*(diff(w(x), x, x, x, x))-(2400*(diff(u(x), x, x)+(diff(w(x), x))*(diff(w(x), x, x))))*(diff(w(x), x))-(1/50000000)*(diff(w(x), x, x))*(120000000000*(diff(u(x), x))+60000000000*(diff(w(x), x))^2-120000000000), u(0) = 0, u(1/2000000) = 0, w(0) = 0, w(1/2000000) = 0, (D(u))(0) = 0, (D(u))(1/2000000) = 0, ((D@@2)(w))(0) = 0, ((D@@2)(w))(1/2000000) = 0, ((D@@4)(w))(0) = 0, ((D@@4)(w))(1/2000000) = 0}

{(63/20000000)*(diff(diff(diff(diff(u(x), x), x), x), x))-120000000000*(diff(diff(u(x), x), x))-60000000000*(diff(diff(w(x), x), x)), -0.2100000000e-29*(diff(diff(diff(diff(diff(diff(w(x), x), x), x), x), x), x))-0.4860000000e-13*(diff(diff(diff(diff(w(x), x), x), x), x))-2400*(diff(diff(u(x), x), x)+(diff(w(x), x))*(diff(diff(w(x), x), x)))*(diff(w(x), x))-(1/50000000)*(diff(diff(w(x), x), x))*(120000000000*(diff(u(x), x))+60000000000*(diff(w(x), x))^2-120000000000), u(0) = 0, u(1/2000000) = 0, w(0) = 0, w(1/2000000) = 0, (D(u))(0) = 0, (D(u))(1/2000000) = 0, ((D@@2)(w))(0) = 0, ((D@@2)(w))(1/2000000) = 0, ((D@@4)(w))(0) = 0, ((D@@4)(w))(1/2000000) = 0}

(1)

dsolve(dsys3, numeric, initmesh = 3024, abserr = 0.1e-4)

`[Length of output exceeds limit of 1000000]`

(2)

``


Download error_length.mw

1 2 3 4 Page 1 of 4