36 Nonlinear PDE’s

36.1 Bateman-Burgers equation
36.2 Benjamin Bona Mahony
36.3 Benjamin Ono
36.4 Born Infeld
36.5 Boussinesq
36.6 Boussinesq type PDE
36.7 Buckmaster
36.8 Camassa Holm
36.9 Chaffee Infante equation
36.10 Clarke’s equation
36.11 Degasperis Procesi
36.12 Dym equation
36.13 Estevez Mansfield Clarkson equation
36.14 Fisher’s equation
36.15 Hunter Saxton
36.16 Kadomtsev Petviashvili
36.17 Klein Gordon (nonlinear)
36.18 special case Klein Gordon (nonlinear)
36.19 Khokhlov Zabolotskaya
36.20 Korteweg de Vries (KdV)
36.21 Lin Tsien equation
36.22 Liouville equation
36.23 Plateau
36.24 Rayleigh
36.25 Sawada Kotera
36.26 Sine Gordon
36.27 Sinh Gordon
36.28 Sinh Poisson
36.29 Thomas equation
36.30 phi equation

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36.1 Bateman-Burgers equation

problem number 195

Added December 27, 2018.

Taken from https://en.wikipedia.org/wiki/List_of_nonlinear_partial_differential_equations

Solve for \(u(x,t)\)

\[ u_t+u u_x = \nu u_{xx} \]

Mathematica

ClearAll[u, x, t, v]; 
 pde = D[u[x, t], t] + u[x, t]*D[u[x, t], x] == v*D[u[x, t], {x, 2}]; 
 sol = AbsoluteTiming[TimeConstrained[DSolve[pde, u[x, t], {x, t}], 60*10]];
 

\[ \left \{\left \{u(x,t)\to -\frac {2 c_1^2 v \tanh \left (c_2 t+c_1 x+c_3\right )+c_2}{c_1}\right \}\right \} \]

Maple

 
u:='u';x:='x';t:='t'; 
pde:=diff(u(x,t),t)+u(x,t)*diff(u(x,t),x)=v*diff(u(x,t),x$2); 
cpu_time := timelimit(60*10,CodeTools[Usage](assign('sol',pdsolve(pde,u(x,t))),output='realtime'));
 

\[ u \left ( x,t \right ) =-2\,v{\it \_C2}\,\tanh \left ( {\it \_C2}\,x+{\it \_C3}\,t+{\it \_C1} \right ) -{\frac {{\it \_C3}}{{\it \_C2}}} \]

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36.2 Benjamin Bona Mahony

problem number 196

Added December 27, 2018.

Taken from https://en.wikipedia.org/wiki/List_of_nonlinear_partial_differential_equations

Solve for \(u(x,t)\)

\[ u_t+u_x + u u+x - u_{xxt} = 0 \]

Mathematica

ClearAll[u, x, t]; 
 pde = D[u[x, t], t] + D[u[x, t], x] + u[x, t]*D[u[x, t], x] - D[D[u[x, t], {x, 2}], t] == 0; 
 sol = AbsoluteTiming[TimeConstrained[DSolve[pde, u[x, t], {x, t}], 60*10]];
 

\[ \left \{\left \{u(x,t)\to \frac {12 c_2 c_1^2 \tanh ^2\left (c_2 t+c_1 x+c_3\right )-8 c_2 c_1^2-c_1-c_2}{c_1}\right \}\right \} \]

Maple

 
u:='u';x:='x';t:='t'; 
pde:=diff(u(x,t),t)+diff(u(x,t),x)+u(x,t)*diff(u(x,t),x)-diff(u(x,t),x,x,t)=0; 
cpu_time := timelimit(60*10,CodeTools[Usage](assign('sol',pdsolve(pde,u(x,t))),output='realtime'));
 

\[ u \left ( x,t \right ) =12\,{\it \_C2}\,{\it \_C3}\, \left ( \tanh \left ( {\it \_C2}\,x+{\it \_C3}\,t+{\it \_C1} \right ) \right ) ^{2}-{\frac {8\,{{\it \_C2}}^{2}{\it \_C3}+{\it \_C2}+{\it \_C3}}{{\it \_C2}}} \]

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36.3 Benjamin Ono

problem number 197

Added December 27, 2018.

Taken from https://en.wikipedia.org/wiki/List_of_nonlinear_partial_differential_equations

Solve for \(u(x,t)\)

\[ u_t+H u_{xx} +u u_x = 0 \]

Important note. \(H\) above is meant to be Hilbert transform. https://en.wikipedia.org/wiki/Benjamin%E2%80%93Ono_equation However, here in the code below it is taken as just a scalar.

Mathematica

ClearAll[u, x, t, h]; 
 pde = D[u[x, t], t] + h*D[u[x, t], {x, 2}] + u[x, t]*D[u[x, t], x] == 0; 
 sol = AbsoluteTiming[TimeConstrained[DSolve[pde, u[x, t], {x, t}], 60*10]];
 

\[ \left \{\left \{u(x,t)\to \frac {2 c_1^2 h \tanh \left (c_2 t+c_1 x+c_3\right )-c_2}{c_1}\right \}\right \} \]

Maple

 
u:='u';x:='x';t:='t'; 
pde:=diff(u(x,t),t)+H*diff(u(x,t),x$2)+u(x,t)*diff(u(x,t),x)=0; 
cpu_time := timelimit(60*10,CodeTools[Usage](assign('sol',pdsolve(pde,u(x,t))),output='realtime'));
 

\[ u \left ( x,t \right ) =2\,H\,{\it \_C2}\,\tanh \left ( {\it \_C2}\,x+{\it \_C3}\,t+{\it \_C1} \right ) -{\frac {{\it \_C3}}{{\it \_C2}}} \]

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36.4 Born Infeld

problem number 198

Added December 27, 2018.

Taken from https://en.wikipedia.org/wiki/List_of_nonlinear_partial_differential_equations

Solve for \(u(x,t)\)

\[ (1-u_t^2) u_{xx} + 2 u_x u_t u_{xt} - (1+ u_x^2) u_{tt}=0 \]

Mathematica

ClearAll[u, x, t]; 
 pde = (1 - D[u[x, t], t]^2)*D[u[x, t], {x, 2}] + 2*D[u[x, t], x]*D[u[x, t], t]*D[D[u[x, t], x], t] - (1 + D[u[x, t], x]^2)*D[u[x, t], {t, 2}] == 0; 
 sol = AbsoluteTiming[TimeConstrained[DSolve[pde, u[x, t], {x, t}], 60*10]];
 

\[ \left \{\left \{u(x,t)\to c_1(t+x)+c_2(t-x)\right \}\right \} \]

Maple

u:='u';x:='x';t:='t'; 
pde:=(1-diff(u(x,t),t)^2)*diff(u(x,t),x$2)+2*diff(u(x,t),x)*diff(u(x,t),t)*diff(u(x,t),x,t)-(1+diff(u(x,t),x)^2)*diff(u(x,t),t$2)=0; 
cpu_time := timelimit(60*10,CodeTools[Usage](assign('sol',pdsolve(pde,u(x,t))),output='realtime'));
 

\[ u \left ( x,t \right ) ={\it \_C7}\, \left ( \tanh \left ( -{\it \_C2}\,t+{\it \_C2}\,x+{\it \_C1} \right ) \right ) ^{3}+{\it \_C5}\,\tanh \left ( -{\it \_C2}\,t+{\it \_C2}\,x+{\it \_C1} \right ) +{\it \_C4} \]

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36.5 Boussinesq

problem number 199

Added December 27, 2018.

Taken from https://en.wikipedia.org/wiki/List_of_nonlinear_partial_differential_equations

Solve for \(u(x,t)\)

\[ u_{tt}-u_{xx}-u_{xxxx} - 3 (u^2)_{xx} = 0 \]

Mathematica

ClearAll[u, x, t]; 
 pde = D[u[x, t], {t, 2}] - D[u[x, t], {x, 2}] - D[u[x, t], {x, 4}] - 3*D[u[x, t]^2, {x, 2}] == 0; 
 sol = AbsoluteTiming[TimeConstrained[DSolve[pde, u[x, t], {x, t}], 60*10]];
 

\[ \left \{\left \{u(x,t)\to -\frac {12 c_1^4 \tanh ^2\left (c_2 t+c_1 x+c_3\right )-8 c_1^4+c_1^2-c_2^2}{6 c_1^2}\right \}\right \} \]

Maple

 
u:='u';x:='x';t:='t'; 
pde:=diff(u(x,t),t$2)-diff(u(x,t),x$2)-diff(u(x,t),x$4)- 3 * diff( u(x,t)^2, x$2)=0; 
cpu_time := timelimit(60*10,CodeTools[Usage](assign('sol',pdsolve(pde,u(x,t))),output='realtime'));
 

\[ u \left ( x,t \right ) =-2\,{{\it \_C2}}^{2} \left ( \tanh \left ( {\it \_C2}\,x+{\it \_C3}\,t+{\it \_C1} \right ) \right ) ^{2}+1/6\,{\frac {8\,{{\it \_C2}}^{4}-{{\it \_C2}}^{2}+{{\it \_C3}}^{2}}{{{\it \_C2}}^{2}}} \]

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36.6 Boussinesq type PDE

problem number 200

Added December 27, 2018.

Taken from https://en.wikipedia.org/wiki/List_of_nonlinear_partial_differential_equations

Solve for \(u(x,t)\)

\[ u_{tt}-u_{xx}-2 \alpha (u u_x)_x - \beta u_{xxtt} = 0 \]

Mathematica

ClearAll[u, x, t]; 
 pde = D[u[x, t], {t, 2}] - D[u[x, t], {x, 2}] - D[u[x, t], {x, 4}] - 3*D[u[x, t]^2, {x, 2}] == 0; 
 sol = AbsoluteTiming[TimeConstrained[DSolve[pde, u[x, t], {x, t}], 60*10]];
 

\[ \left \{\left \{u(x,t)\to -\frac {12 c_1^4 \tanh ^2\left (c_2 t+c_1 x+c_3\right )-8 c_1^4+c_1^2-c_2^2}{6 c_1^2}\right \}\right \} \]

Maple

 
u:='u';x:='x';t:='t';alpha:='alpha';beta:='beta'; 
pde:=diff(u(x,t),t$2)-diff(u(x,t),x$2)-2*alpha*diff( (u(x,t)*diff(u(x,t),x)) ,x) - beta*diff(u(x,t),x,x,t,t)=0; 
cpu_time := timelimit(60*10,CodeTools[Usage](assign('sol',pdsolve(pde,u(x,t))),output='realtime'));
 

\[ u \left ( x,t \right ) =-6\,{\frac {{{\it \_C3}}^{2}\beta \, \left ( \tanh \left ( {\it \_C2}\,x+{\it \_C3}\,t+{\it \_C1} \right ) \right ) ^{2}}{\alpha }}+1/2\,{\frac {8\,{{\it \_C2}}^{2}{{\it \_C3}}^{2}\beta -{{\it \_C2}}^{2}+{{\it \_C3}}^{2}}{\alpha \,{{\it \_C2}}^{2}}} \]

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36.7 Buckmaster

problem number 201

Added December 27, 2018.

Taken from https://en.wikipedia.org/wiki/List_of_nonlinear_partial_differential_equations

Solve for \(u(x,t)\)

\[ u_t = (u^4)_{xx} + (u^3)_x \]

Mathematica

ClearAll[u, x, t]; 
 pde = D[u[x, t], t] == D[u[x, t]^4, {x, 2}] + D[u[x, t]^3, x]; 
 sol = AbsoluteTiming[TimeConstrained[DSolve[pde, u[x, t], {x, t}], 60*10]];
 

\[ \text {Failed} \]

Maple

 
u:='u';x:='x';t:='t'; 
pde:=diff(u(x,t),t)= diff(u(x,t)^4,x$2)+diff(u(x,t)^3,x); 
cpu_time := timelimit(60*10,CodeTools[Usage](assign('sol',pdsolve(pde,u(x,t))),output='realtime'));
 

\[ u \left ( x,t \right ) =\RootOf \left ( {\it \_C1}\,x+{\it \_C2}\,t+{\it \_C3}+\int ^{{\it \_Z}}\!4\,{\frac {{{\it \_C1}}^{2}{{\it \_f}}^{3}}{{\it \_C1}\,{{\it \_f}}^{3}+4\,{\it \_C3}\,{{\it \_C1}}^{2}-{\it \_C2}\,{\it \_f}}}{d{\it \_f}}+{\it \_C4} \right ) \] Answer in terms of RootOf.

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36.8 Camassa Holm

problem number 202

Added December 27, 2018.

Taken from https://en.wikipedia.org/wiki/List_of_nonlinear_partial_differential_equations

Solve for \(u(x,t)\)

\[ u_t + 2 k u_x - u_{xxt} + 3 u u_x = 2 u_x u_{xx}+ u u_{xxx} \]

Mathematica

ClearAll[u, x, t, k]; 
 pde = D[u[x, t], t] + 2*k*D[u[x, t], x] - D[D[u[x, t], {x, 2}], t] + 3*u[x, t]*D[u[x, t], x] == 2*D[u[x, t], x]*D[u[x, t], {x, 2}] + u[x, t]*D[u[x, t], {x, 3}]; 
 sol = AbsoluteTiming[TimeConstrained[DSolve[pde, u[x, t], {x, t}], 60*10]];
 

\[ \text {Failed} \]

Maple

 
u:='u';x:='x';t:='t'; 
pde:=diff(u(x,t),t)+2*k*diff(u(x,t),x)- diff(u(x,t),x,x,t)+3*u(x,t)*diff(u(x,t),x)=2*diff(u(x,t),x)*diff(u(x,t),x$2)+u(x,t)*diff(u(x,t),x$3); 
cpu_time := timelimit(60*10,CodeTools[Usage](assign('sol',pdsolve(pde,u(x,t))),output='realtime'));
 

\[ u \left ( x,t \right ) ={\frac {1}{{\it \_C1}} \left ( \left ( \RootOf \left ( -i{\it \_C1}\,x-i{\it \_C2}\,t-i{\it \_C3}+\int ^{-{\frac {-{{\it \_Z}}^{2}+{\it \_C2}}{{\it \_C1}}}}\!{\frac {\sqrt {{\it \_C1}\,{\it \_f}+{\it \_C2}}}{\sqrt {{{\it \_C1}}^{3}{\it \_C3}\,{\it \_f}+{{\it \_C1}}^{2}{\it \_C2}\,{\it \_C3}-{\it \_C1}\,{{\it \_f}}^{3}-2\,{\it \_C1}\,{{\it \_f}}^{2}k+{\it \_C4}\,{{\it \_C1}}^{2}-{\it \_C2}\,{{\it \_f}}^{2}}}}{d{\it \_f}}{\it \_C1}+{\it \_C5}\,{\it \_C1} \right ) \right ) ^{2}-{\it \_C2} \right ) } \] Answer in terms of RootOf.

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36.9 Chaffee Infante equation

problem number 203

Added December 27, 2018.

Taken from https://en.wikipedia.org/wiki/List_of_nonlinear_partial_differential_equations

Solve for \(u(x,t)\)

\[ u_t = u_{xx} + \lambda (u^3 - u) = 0 \]

Mathematica

ClearAll[u, x, t, lambda]; 
 pde = D[u[x, t], t] - D[u[x, t], {x, 2}] + lambda*(u[x, t]^3 - u[x, t]) == 0; 
 sol = AbsoluteTiming[TimeConstrained[DSolve[pde, u[x, t], {x, t}], 60*10]];
 

\[ \text {Failed} \]

Maple

 
u:='u';x:='x';t:='t'; 
pde:=diff(u(x,t),t)-diff(u(x,t),x$2)+lambda*(u(x,t)^3-u(x,t))=0; 
cpu_time := timelimit(60*10,CodeTools[Usage](assign('sol',pdsolve(pde,u(x,t))),output='realtime'));
 

\[ u \left ( x,t \right ) =1/2\,\tanh \left ( -3/4\,\lambda \,t+1/4\,\sqrt {2}\sqrt {\lambda }x+{\it \_C1} \right ) -1/2 \]

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36.10 Clarke’s equation

problem number 204

Added December 27, 2018.

Taken from https://en.wikipedia.org/wiki/List_of_nonlinear_partial_differential_equations

Solve for \(\theta (x,t)\)

\[ \left ( \theta _t - \gamma e^\theta \right )_{tt} = \left ( \theta _t - e^\theta \right )_{xx} \]

Mathematica

ClearAll[theta, x, t, gamma]; 
 pde = D[D[theta[x, t], t] - gamma*Exp[theta[x, t]], {t, 2}] == D[D[theta[x, t], t] - Exp[theta[x, t]], {x, 2}]; 
 sol = AbsoluteTiming[TimeConstrained[DSolve[pde, theta[x, t], {x, t}], 60*10]];
 

\[ \text {Failed} \]

Maple

 
theta:='theta';x:='x';t:='t';g:='g'; 
pde := diff(diff(theta(x,t),t)-g*exp(theta(x,t)),t$2) = diff( diff(theta(x,t),t)-exp(theta(x,t)),x$2); 
cpu_time := timelimit(60*10,CodeTools[Usage](assign('sol',pdsolve(pde,theta(x,t))),output='realtime'));
 

\[ \text { sol=() } \]

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36.11 Degasperis Procesi

problem number 205

Added December 27, 2018.

Taken from https://en.wikipedia.org/wiki/List_of_nonlinear_partial_differential_equations

Solve for \(u(x,t)\)

\[ u_t - u_{xxt} + 4 u u_x = 3 u_x u_xx + u u_{xxx} \]

Mathematica

ClearAll[u, x, t]; 
 pde = D[u[x, t], t] - D[D[u[x, t], {x, 2}], t] + 4*u[x, t]*D[u[x, t], x] == 3*D[u[x, t], x]*D[u[x, t], {x, 2}] + u[x, t]*D[u[x, t], {x, 3}]; 
 sol = AbsoluteTiming[TimeConstrained[DSolve[pde, u[x, t], {x, t}], 60*10]];
 

\[ \text {Failed} \]

Maple

 
u:='u';x:='x';t:='t'; 
pde:= diff(u(x,t),t)-diff(u(x,t),x,x,t)+4*u(x,t)*diff(u(x,t),x)=3*diff(u(x,t),x)*diff(u(x,t),x$2)+u(x,t)*diff(u(x,t),x$3); 
cpu_time := timelimit(60*10,CodeTools[Usage](assign('sol',pdsolve(pde,u(x,t),'build')),output='realtime'));
 

\[ {\it PDESolStruc} \left ( u \left ( x,t \right ) ={\frac {{\it \_F1} \left ( x \right ) }{-{\it \_c}_{{2}}t+{\it \_C2}}},[ \left \{ \left \{ {\it \_F1} \left ( x \right ) ={\it ODESolStruc} \left ( {\it \_a},[ \left \{ \left ( {\frac {{\rm d}^{2}}{{\rm d}{{\it \_a}}^{2}}}{\it \_b} \left ( {\it \_a} \right ) \right ) \left ( {\it \_b} \left ( {\it \_a} \right ) \right ) ^{2}+{\frac { \left ( {\frac {\rm d}{{\rm d}{\it \_a}}}{\it \_b} \left ( {\it \_a} \right ) \right ) ^{2}{\it \_b} \left ( {\it \_a} \right ) {\it \_a}+3\, \left ( {\it \_b} \left ( {\it \_a} \right ) \right ) ^{2}{\frac {\rm d}{{\rm d}{\it \_a}}}{\it \_b} \left ( {\it \_a} \right ) +{\it \_b} \left ( {\it \_a} \right ) \left ( {\frac {\rm d}{{\rm d}{\it \_a}}}{\it \_b} \left ( {\it \_a} \right ) \right ) {\it \_c}_{{2}}-4\,{\it \_b} \left ( {\it \_a} \right ) {\it \_a}-{\it \_a}\,{\it \_c}_{{2}}}{{\it \_a}}}=0 \right \} , \left \{ {\it \_a}={\it \_F1} \left ( x \right ) ,{\it \_b} \left ( {\it \_a} \right ) ={\frac {\rm d}{{\rm d}x}}{\it \_F1} \left ( x \right ) \right \} , \left \{ x=\int \! \left ( {\it \_b} \left ( {\it \_a} \right ) \right ) ^{-1}\,{\rm d}{\it \_a}+{\it \_C1},{\it \_F1} \left ( x \right ) ={\it \_a} \right \} ] \right ) \right \} \right \} ] \right ) \] But still has unresolved ODE’s in solution

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36.12 Dym equation

problem number 206

Added December 27, 2018.

Taken from https://en.wikipedia.org/wiki/List_of_nonlinear_partial_differential_equations

Solve for \(u(x,t)\)

\[ u_t =u^3 u_{xxx} \]

Mathematica

ClearAll[u, x, t]; 
 pde = D[u[x, t], t] == u[x, t]^3*D[u[x, t], {x, 3}]; 
 sol = AbsoluteTiming[TimeConstrained[DSolve[pde, u[x, t], {x, t}], 60*10]];
 

\[ \text {Failed} \]

Maple

 
u:='u';x:='x';t:='t'; 
pde:= diff(u(x,t),t)=u(x,t)^3 * diff(u(x,t),x$3); 
cpu_time := timelimit(60*10,CodeTools[Usage](assign('sol',pdsolve(pde,u(x,t),'build')),output='realtime'));
 

\[ u \left ( x,t \right ) ={\frac {1}{\sqrt [3]{-3\,{\it \_c}_{{1}}t+{\it \_C4}}}\RootOf \left ( -\int ^{{\it \_Z}}\! \left ( \RootOf \left ( -\ln \left ( {\it \_f} \right ) +2\,\int ^{{\it \_Z}}\!{\frac {{\it \_h}}{2\,\sqrt [3]{2}\sqrt [3]{-{{\it \_c}_{{1}}}^{2}}\RootOf \left ( \AiryBi \left ( {\it \_Z} \right ) \sqrt [3]{2}\sqrt [3]{-{{\it \_c}_{{1}}}^{2}}{\it \_C1}\,{\it \_h}+\sqrt [3]{2}\sqrt [3]{-{{\it \_c}_{{1}}}^{2}}{\it \_h}\,\AiryAi \left ( {\it \_Z} \right ) +2\,\AiryBi \left ( 1,{\it \_Z} \right ) {\it \_C1}\,{\it \_c}_{{1}}+2\,\AiryAi \left ( 1,{\it \_Z} \right ) {\it \_c}_{{1}} \right ) +{{\it \_h}}^{2}}}{d{\it \_h}}+{\it \_C2} \right ) \right ) ^{-1}{d{\it \_f}}+x+{\it \_C3} \right ) } \] has RootOf

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36.13 Estevez Mansfield Clarkson equation

problem number 207

Added December 27, 2018.

Taken from https://en.wikipedia.org/wiki/List_of_nonlinear_partial_differential_equations

Solve for \(u(x,y,t)\)

\[ u_{tyyy} + \beta u_y u_{yt} + \beta u_{yy} u_t + u_{tt} = 0 \]

Mathematica

ClearAll[u, x, t, y, beta]; 
 pde = D[D[u[x, y, t], t], {y, 3}] + beta*D[u[x, y, t], y]*D[D[u[x, y, t], y], t] + beta*D[u[x, y, t], {y, 2}]*D[u[x, y, t], t] + D[u[x, y, t], {t, 2}] == 0; 
 sol = AbsoluteTiming[TimeConstrained[DSolve[pde, u[x, y, t], {x, y, t}], 60*10]];
 

\[ \left \{\left \{u(x,y,t)\to \frac {\beta c_4(x)+6 c_1(x) \tanh \left (-4 t c_1(x){}^3+y c_1(x)+c_3(x)\right )}{\beta }\right \}\right \} \]

Maple

 
u:='u';x:='x';t:='t';y:='y';beta='beta'; 
pde:= diff(u(x,y,t),t,y,y,y)+ beta*diff(u(x,y,t),y)*diff(u(x,y,t),y,t) +  beta*diff(u(x,y,t),y$2)*diff(u(x,y,t),t) + diff(u(x,y,t),t$2)=0; 
cpu_time := timelimit(60*10,CodeTools[Usage](assign('sol',pdsolve(pde,u(x,y,t))),output='realtime'));
 

\[ u \left ( x,y,t \right ) =6\,{\frac {{\it \_C3}\,\tanh \left ( -4\,{{\it \_C3}}^{3}t+{\it \_C2}\,x+{\it \_C3}\,y+{\it \_C1} \right ) }{\beta }}+{\it \_C5} \]

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36.14 Fisher’s equation

problem number 208

Added December 27, 2018.

Taken from https://en.wikipedia.org/wiki/List_of_nonlinear_partial_differential_equations

Solve for \(u(x,t)\)

\[ u_t = u(1-u)+u_{xx} \]

Mathematica

ClearAll[u, x, t]; 
 pde = D[u[x, t], t] == u[x, t]*(1 - u[x, t]) + D[u[x, t], {x, 2}]; 
 sol = AbsoluteTiming[TimeConstrained[DSolve[pde, u[x, t], {x, t}], 60*10]];
 

\[ \left \{\left \{u(x,t)\to \frac {1}{4} \left (\tanh \left (-c_3+\frac {5 t}{12}-\frac {x}{2 \sqrt {6}}\right )+1\right ){}^2\right \},\left \{u(x,t)\to -\frac {1}{4} \left (-3+\tanh \left (-c_3+\frac {5 t}{12}-\frac {i x}{2 \sqrt {6}}\right )\right ) \left (1+\tanh \left (-c_3+\frac {5 t}{12}-\frac {i x}{2 \sqrt {6}}\right )\right )\right \},\left \{u(x,t)\to -\frac {1}{4} \left (-3+\tanh \left (-c_3+\frac {5 t}{12}+\frac {i x}{2 \sqrt {6}}\right )\right ) \left (1+\tanh \left (-c_3+\frac {5 t}{12}+\frac {i x}{2 \sqrt {6}}\right )\right )\right \},\left \{u(x,t)\to \frac {1}{4} \left (\tanh \left (-c_3+\frac {5 t}{12}+\frac {x}{2 \sqrt {6}}\right )+1\right ){}^2\right \},\left \{u(x,t)\to \frac {1}{4} \left (\tanh \left (c_3+\frac {5 t}{12}-\frac {x}{2 \sqrt {6}}\right )+1\right ){}^2\right \},\left \{u(x,t)\to -\frac {1}{4} \left (-3+\tanh \left (c_3+\frac {5 t}{12}-\frac {i x}{2 \sqrt {6}}\right )\right ) \left (1+\tanh \left (c_3+\frac {5 t}{12}-\frac {i x}{2 \sqrt {6}}\right )\right )\right \},\left \{u(x,t)\to -\frac {1}{4} \left (-3+\tanh \left (c_3+\frac {5 t}{12}+\frac {i x}{2 \sqrt {6}}\right )\right ) \left (1+\tanh \left (c_3+\frac {5 t}{12}+\frac {i x}{2 \sqrt {6}}\right )\right )\right \},\left \{u(x,t)\to \frac {1}{4} \left (\tanh \left (c_3+\frac {5 t}{12}+\frac {x}{2 \sqrt {6}}\right )+1\right ){}^2\right \}\right \} \]

Maple

 
u:='u';x:='x';t:='t'; 
pde:= diff(u(x,t),t)= u(x,t)*(1-u(x,t))+ diff(u(x,t),x$2); 
cpu_time := timelimit(60*10,CodeTools[Usage](assign('sol',{PDEtools:-TWSolutions(pde,u(x,t))}),output='realtime'));
 

\[ \left \{ \left \{ u \left ( x,t \right ) =1 \right \} , \left \{ u \left ( x,t \right ) =1/4\, \left ( \tanh \left ( -{\frac {5\,t}{12}}-1/12\,\sqrt {6}x+{\it \_C1} \right ) \right ) ^{2}-1/2\,\tanh \left ( -{\frac {5\,t}{12}}-1/12\,\sqrt {6}x+{\it \_C1} \right ) +1/4 \right \} , \left \{ u \left ( x,t \right ) =1/4\, \left ( \tanh \left ( -{\frac {5\,t}{12}}+1/12\,\sqrt {6}x+{\it \_C1} \right ) \right ) ^{2}-1/2\,\tanh \left ( -{\frac {5\,t}{12}}+1/12\,\sqrt {6}x+{\it \_C1} \right ) +1/4 \right \} , \left \{ u \left ( x,t \right ) =-1/4\, \left ( \tanh \left ( -{\frac {5\,t}{12}}-i/12\sqrt {6}x+{\it \_C1} \right ) \right ) ^{2}-1/2\,\tanh \left ( -{\frac {5\,t}{12}}-i/12\sqrt {6}x+{\it \_C1} \right ) +3/4 \right \} , \left \{ u \left ( x,t \right ) =-1/4\, \left ( \tanh \left ( -{\frac {5\,t}{12}}+i/12\sqrt {6}x+{\it \_C1} \right ) \right ) ^{2}-1/2\,\tanh \left ( -{\frac {5\,t}{12}}+i/12\sqrt {6}x+{\it \_C1} \right ) +3/4 \right \} , \left \{ u \left ( x,t \right ) =1/4\, \left ( \tanh \left ( {\frac {5\,t}{12}}-1/12\,\sqrt {6}x+{\it \_C1} \right ) \right ) ^{2}+1/2\,\tanh \left ( {\frac {5\,t}{12}}-1/12\,\sqrt {6}x+{\it \_C1} \right ) +1/4 \right \} , \left \{ u \left ( x,t \right ) =1/4\, \left ( \tanh \left ( {\frac {5\,t}{12}}+1/12\,\sqrt {6}x+{\it \_C1} \right ) \right ) ^{2}+1/2\,\tanh \left ( {\frac {5\,t}{12}}+1/12\,\sqrt {6}x+{\it \_C1} \right ) +1/4 \right \} , \left \{ u \left ( x,t \right ) =-1/4\, \left ( \tanh \left ( {\frac {5\,t}{12}}-i/12\sqrt {6}x+{\it \_C1} \right ) \right ) ^{2}+1/2\,\tanh \left ( {\frac {5\,t}{12}}-i/12\sqrt {6}x+{\it \_C1} \right ) +3/4 \right \} , \left \{ u \left ( x,t \right ) =-1/4\, \left ( \tanh \left ( {\frac {5\,t}{12}}+i/12\sqrt {6}x+{\it \_C1} \right ) \right ) ^{2}+1/2\,\tanh \left ( {\frac {5\,t}{12}}+i/12\sqrt {6}x+{\it \_C1} \right ) +3/4 \right \} \right \} \]

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36.15 Hunter Saxton

problem number 209

Added December 27, 2018.

Taken from https://en.wikipedia.org/wiki/List_of_nonlinear_partial_differential_equations

Solve for \(u(x,t)\)

\[ \left ( u_t + u u_x) \right )_x = \frac {1}{2} (u_x)^2 \]

Mathematica

ClearAll[u, x, t]; 
 pde = D[D[u[x, t], t] + u[x, t]*D[u[x, t], x], x] == (1*D[u[x, t], x]^2)/2; 
 sol = AbsoluteTiming[TimeConstrained[DSolve[pde, u[x, t], {x, t}], 60*10]];
 

\[ \text {Failed} \]

Maple

 
u:='u';x:='x';t:='t'; 
pde:= diff( (diff(u(x,t),t)+ u(x,t)* diff(u(x,t),x)) , x) = 1/2* (diff(u(x,t),x))^2; 
cpu_time := timelimit(60*10,CodeTools[Usage](assign('sol',pdsolve(pde,u(x,t),'build')),output='realtime'));
 

\[ u \left ( x,t \right ) =2\,{\frac {\RootOf \left ( -{\it \_C2}\,{{\it \_c}_{{1}}}^{3}-x{{\it \_c}_{{1}}}^{3}-2\,{\it \_C1}\,\sqrt {{\it \_Z}}{\it \_c}_{{1}}+2\,{{\it \_C1}}^{2}\ln \left ( \sqrt {{\it \_Z}}{\it \_c}_{{1}}+{\it \_C1} \right ) +{\it \_Z}\,{{\it \_c}_{{1}}}^{2} \right ) }{{\it \_c}_{{1}}t+2\,{\it \_C3}} \left ( {\frac {{\it \_c}_{{1}}t}{{\it \_c}_{{1}}t+2\,{\it \_C3}}}+2\,{\frac {{\it \_C3}}{{\it \_c}_{{1}}t+2\,{\it \_C3}}} \right ) ^{-1}} \] with RootOf

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36.16 Kadomtsev Petviashvili

problem number 210

Added December 27, 2018.

Taken from https://en.wikipedia.org/wiki/List_of_nonlinear_partial_differential_equations

Solve for \(u(x,y,t)\)

\[ \left ( u_t + u u_x + \epsilon ^2 u_{xxx} \right )_x + \lambda u_{yy} = 0 \]

Mathematica

ClearAll[u, x, t]; 
 pde = D[D[u[x, y, t], t] + u[x, y, t]*D[u[x, y, t], x] + eps^2*D[u[x, y, t], {x, 3}], t] + lambda*D[u[x, y, t], {y, 2}] == 0; 
 sol = AbsoluteTiming[TimeConstrained[DSolve[pde, u[x, y, t], {x, y, t}], 60*10]];
 

\[ \left \{\left \{u(x,y,t)\to -\frac {12 c_3 c_1^3 \text {eps}^2 \tanh ^2\left (c_3 t+c_1 x+c_2 y+c_4\right )-8 c_3 c_1^3 \text {eps}^2+c_2^2 \lambda +c_3^2}{c_1 c_3}\right \}\right \} \]

Maple

 
u:='u';x:='x';t:='t';y:='y';lambda:='lambda';epsilon:='epsilon'; 
pde:= diff( diff(u(x,y,t),t)+u(x,y,t)*diff(u(x,y,t),x)+epsilon^2* diff(u(x,y,t),x$3),x)+ lambda*diff(u(x,y,t),y$2)=0; 
cpu_time := timelimit(60*10,CodeTools[Usage](assign('sol',pdsolve(pde,u(x,y,t))),output='realtime'));
 

\[ u \left ( x,y,t \right ) =-12\,{\epsilon }^{2}{{\it \_C2}}^{2} \left ( \tanh \left ( {\it \_C2}\,x+{\it \_C3}\,y+{\it \_C4}\,t+{\it \_C1} \right ) \right ) ^{2}+{\frac {8\,{{\it \_C2}}^{4}{\epsilon }^{2}-{{\it \_C3}}^{2}\lambda -{\it \_C4}\,{\it \_C2}}{{{\it \_C2}}^{2}}} \]

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36.17 Klein Gordon (nonlinear)

problem number 211

Added December 27, 2018.

Taken from https://en.wikipedia.org/wiki/List_of_nonlinear_partial_differential_equations

Solve for \(u(x,y)\)

\[ u_{xx}+u_{yy}+ \lambda u^p=0 \]

Mathematica

ClearAll[u, x, y, lambda]; 
 pde = Laplacian[u[x, y], {x, y}] + lambda*u[x, y]^p == 0; 
 sol = AbsoluteTiming[TimeConstrained[DSolve[pde, u[x, y], {x, y}], 60*10]];
 

\[ \text {Failed} \]

Maple

 
u:='u';x:='x';y:='y';lambda:='lambda'; 
pde:=diff(u(x,y),x$2)+diff(u(x,y),y$2)+lambda*u(x,y)^p=0; 
cpu_time := timelimit(60*10,CodeTools[Usage](assign('sol',pdsolve(pde,u(x,y),'build')),output='realtime'));
 

\[ \text { sol=() } \]

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36.18 special case Klein Gordon (nonlinear)

problem number 212

Added December 27, 2018.

Solve for \(u(x,y)\)

\[ u_{xx}+u_{yy}+ u^2=0 \]

Mathematica

ClearAll[u, x, y, lambda]; 
 pde = Laplacian[u[x, y], {x, y}] + u[x, y]^2 == 0; 
 sol = AbsoluteTiming[TimeConstrained[DSolve[pde, u[x, y], {x, y}], 60*10]];
 

\[ \text {Failed} \]

Maple

 
u:='u';x:='x';y:='y';lambda:='lambda'; 
pde:=diff(u(x,y),x$2)+diff(u(x,y),y$2)+u(x,y)^2=0; 
cpu_time := timelimit(60*10,CodeTools[Usage](assign('sol',pdsolve(pde,u(x,y))),output='realtime'));
 

\[ u \left ( x,y \right ) =-6\,{\it WeierstrassP} \left ( {\it \_C1}\,x+{\it \_C2}\,y+2\,{\it \_C3},0,{\it \_C4} \right ) \left ( {{\it \_C1}}^{2}+{{\it \_C2}}^{2} \right ) \]

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36.19 Khokhlov Zabolotskaya

problem number 213

Added December 27, 2018.

Taken from https://en.wikipedia.org/wiki/List_of_nonlinear_partial_differential_equations

Solve for \(u(x,y,t)\)

\[ u_{x t} - (u u_x)_x = u_{yy} \]

Mathematica

ClearAll[u, x, y, t]; 
 pde = D[D[u[x, y, t], x], t] - D[u[x, y, t]*D[u[x, y, t], x], x] == D[u[x, y, t], {y, 2}]; 
 sol = AbsoluteTiming[TimeConstrained[DSolve[pde, u[x, y, t], {x, y, t}], 60*10]];
 

\[ \text {Failed} \]

Maple

 
u:='u';x:='x';y:='y';t:='t'; 
pde:=diff(u(x,y,t),x,t)- diff( (u(x,y,t)* diff(u(x,y,t),x)) ,x ) = diff(u(x,y,t),y$2); 
cpu_time := timelimit(60*10,CodeTools[Usage](assign('sol',pdsolve(pde,u(x,y,t))),output='realtime'));
 

\[ u \left ( x,y,t \right ) ={\frac {{\it \_C3}\,{\it \_C1}-{{\it \_C2}}^{2}+\sqrt {2\, \left ( {\it \_C1}\,x+{\it \_C2}\,y+{\it \_C3}\,t+{\it \_C4} \right ) {{\it \_C1}}^{2}{\it \_C4}+{{\it \_C1}}^{2}{{\it \_C3}}^{2}-2\,{\it \_C1}\,{{\it \_C2}}^{2}{\it \_C3}+{{\it \_C2}}^{4}+2\,{{\it \_C1}}^{2}{\it \_C5}}}{{{\it \_C1}}^{2}}} \]

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36.20 Korteweg de Vries (KdV)

problem number 214

Added December 27, 2018.

Taken from https://en.wikipedia.org/wiki/List_of_nonlinear_partial_differential_equations

Solve for \(u(x,t)\)

\[ u_t + (u_x)^3+ 6 u u_x = 0 \]

Mathematica

ClearAll[u, x, t]; 
 pde = D[u[x, t], t] + D[u[x, t], x]^3 + 6*u[x, t]*D[u[x, t], x] == 0; 
 sol = AbsoluteTiming[TimeConstrained[DSolve[pde, u[x, t], {x, t}], 60*10]];
 

\[ \left \{\left \{u(x,t)\to \frac {-18 c_1 t x-18 c_2 t-9 c_1^2 x^2-18 c_1 c_2 x-9 c_2^2-c_1-9 t^2}{6 c_1^2}\right \}\right \} \]

Maple

 
u:='u';x:='x';t:='t'; 
pde:=diff(u(x,t),t)+ diff( u(x,t),x )^3 + 6 * u(x,t)* diff(u(x,t),x) = 0; 
cpu_time := timelimit(60*10,CodeTools[Usage](assign('sol',pdsolve(pde,u(x,t))),output='realtime'));
 

\[ u \left ( x,t \right ) =-3/2\,{{\it \_C1}}^{2}+3\,{\it \_C1}\, \left ( {\it \_c}_{{2}}t+x \right ) -3/2\, \left ( {\it \_c}_{{2}}t+x \right ) ^{2}-1/6\,{\it \_c}_{{2}} \]

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36.21 Lin Tsien equation

problem number 215

Added December 27, 2018.

Taken from https://en.wikipedia.org/wiki/List_of_nonlinear_partial_differential_equations

Solve for \(u(x,y,t)\)

\[ 2 u_{tx} + u_x u_{xx} - u_{yy} = 0 \]

Mathematica

ClearAll[u, x, t]; 
 pde = 2*D[u[x, y, t], t, x] + D[u[x, y, t], x]*D[u[x, y, t], {x, 2}] - D[u[x, y, t], {y, 2}] == 0; 
 sol = AbsoluteTiming[TimeConstrained[DSolve[pde, u[x, y, t], {x, y, t}], 60*10]];
 

\[ \text {Failed} \]

Maple

 
u:='u';x:='x';t:='t';y:='y'; 
pde:=2*diff(u(x,y,t),t,x)+ diff(u(x,y,t),x)* diff(u(x,y,t),x$2) - diff(u(x,y,t),y$2) = 0; 
cpu_time := timelimit(60*10,CodeTools[Usage](assign('sol',pdsolve(pde,u(x,y,t))),output='realtime'));
 

\[ u \left ( x,y,t \right ) ={\it \_C4}+{\it \_C5}\, \left ( {\it \_C1}\,x+{\it \_C2}\,y+{\it \_C3}\,t+{\it \_C4} \right ) \]

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36.22 Liouville equation

problem number 216

Added December 27, 2018.

Taken from https://en.wikipedia.org/wiki/List_of_nonlinear_partial_differential_equations

Solve for \(u(x,y)\)

\[ u_{xx} + u_{yy} +e^{\lambda u} = 0 \]

Mathematica

ClearAll[u, x, lam, y]; 
 pde = Laplacian[u[x, y], {x, y}] + Exp[lam*u[x, y]] == 0; 
 sol = AbsoluteTiming[TimeConstrained[DSolve[pde, u[x, y], {x, y}], 60*10]];
 

\[ \text {Failed} \]

Maple

 
u:='u';x:='x';y:='y';lambda:='lambda'; 
pde:=diff(u(x,y),x$2)+ diff(u(x,y),y$2)+exp(lambda*u(x,y))=0; 
cpu_time := timelimit(60*10,CodeTools[Usage](assign('sol',pdsolve(pde,u(x,y))),output='realtime'));
 

\[ \text { sol=() } \]

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36.23 Plateau

problem number 217

Added December 27, 2018.

Taken from https://en.wikipedia.org/wiki/List_of_nonlinear_partial_differential_equations

Solve for \(u(x,y)\)

\[ (1+u_y^2)u_{xx} - 2 u_x u_y y_{xy} + (1+u_x^2) u_{yy} = 0 \]

Mathematica

ClearAll[u, x, y]; 
 pde = (1 + D[u[x, y], y]^2)*D[u[x, y], {x, 2}] - 2*D[u[x, y], x]*D[u[x, y], y]*D[u[x, y], x, y] + (1 + D[u[x, y], x]^2)*D[u[x, y], {y, 2}] == 0; 
 sol = AbsoluteTiming[TimeConstrained[DSolve[pde, u[x, y], {x, y}], 60*10]];
 

\[ \text {Failed} \]

Maple

 
u:='u';x:='x';y:='y'; 
pde:=(1+diff(u(x,y),y)^2)* diff(u(x,y),x$2)-2* diff(u(x,y),x)* 
       diff(u(x,y),y)*diff(u(x,y),x,y)+ 
       (1+diff(u(x,y),x)^2)*diff(u(x,y),y$2)=0; 
cpu_time := timelimit(60*10,CodeTools[Usage](assign('sol',pdsolve(pde,u(x,y))),output='realtime'));
 

\[ u \left ( x,y \right ) ={\it \_C7}\, \left ( \tanh \left ( {\it \_C2}\,x-i{\it \_C2}\,y+{\it \_C1} \right ) \right ) ^{3}+{\it \_C5}\,\tanh \left ( {\it \_C2}\,x-i{\it \_C2}\,y+{\it \_C1} \right ) +{\it \_C4} \]

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36.24 Rayleigh

problem number 218

Added December 27, 2018.

Taken from https://en.wikipedia.org/wiki/List_of_nonlinear_partial_differential_equations

Solve for \(u(x,t)\)

\[ u_{tt} - u_{xx} = \epsilon (u_t - u_t^3) \]

Mathematica

ClearAll[u, x, t, epsilon]; 
 pde = D[u[x, t], {t, 2}] - D[u[x, t], {x, 2}] == epsilon*(D[u[x, t], t] - D[u[x, t], t]^3); 
 sol = AbsoluteTiming[TimeConstrained[DSolve[pde, u[x, t], {x, t}], 60*10]];
 

\[ \text {Failed} \]

Maple

 
u:='u';x:='x';t:='t';epsilon:='epsilon'; 
pde:=diff(u(x,t),t$2)-diff(u(x,t),x$2)=epsilon*(diff(u(x,t),t)-diff(u(x,t),t)^3); 
cpu_time := timelimit(60*10,CodeTools[Usage](assign('sol',pdsolve(pde,u(x,t),'build')),output='realtime'));
 

\[ u \left ( x,t \right ) =1/2\,{\it \_c}_{{1}}{x}^{2}+{\it \_C1}\,x+{\it \_C2}+\int \!\RootOf \left ( t+\int ^{{\it \_Z}}\! \left ( {{\it \_f}}^{3}\epsilon -{\it \_f}\,\epsilon -{\it \_c}_{{1}} \right ) ^{-1}{d{\it \_f}}+{\it \_C3} \right ) \,{\rm d}t+{\it \_C4} \] Has RootOf

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36.25 Sawada Kotera

problem number 219

Added December 27, 2018.

Taken from https://en.wikipedia.org/wiki/List_of_nonlinear_partial_differential_equations

Solve for \(u(x,t)\)

\[ u_t + 45 u^2 u_x + 15 u_x u_{xx} + 15 u u_{xxx} + u_{xxxxx} = 0 \]

Mathematica

ClearAll[phi, x, t]; 
 pde = D[u[x, t], t] + 45*u[x, t]^2*D[u[x, t], x] + 15*D[u[x, t], x]*D[u[x, t], {x, 2}] + 15*u[x, t]*D[u[x, t], {x, 3}] + D[u[x, t], {x, 5}] == 0; 
 sol = AbsoluteTiming[TimeConstrained[DSolve[pde, u[x, t], {x, t}], 60*10]];
 

\[ \left \{\left \{u(x,t)\to -\frac {4}{3} c_1^2 \left (3 \tanh ^2\left (-16 c_1^5 t+c_1 x+c_3\right )-2\right )\right \},\left \{u(x,t)\to \frac {-30 c_1^{5/2} \tanh ^2\left (c_2 t+c_1 x+c_3\right )+20 c_1^{5/2}+\sqrt {5} \sqrt {4 c_1^5-c_2}}{15 \sqrt {c_1}}\right \},\left \{u(x,t)\to -\frac {30 c_1^{5/2} \tanh ^2\left (c_2 t+c_1 x+c_3\right )-20 c_1^{5/2}+\sqrt {5} \sqrt {4 c_1^5-c_2}}{15 \sqrt {c_1}}\right \}\right \} \]

Maple

 
u:='u';x:='x';t:='t'; 
pde:=diff(u(x,t),t)+45* u(x,t)^2* diff(u(x,t),x)+ 15* diff(u(x,t),x)* 
      diff(u(x,t),x$2)+15*u(x,t)*diff(u(x,t),x$3)+diff(u(x,t),x$5); 
cpu_time := timelimit(60*10,CodeTools[Usage](assign('sol',{PDEtools:-TWSolutions(pde,u(x,t))}),output='realtime'));
 

\[ \left \{ \left \{ u \left ( x,t \right ) ={\it \_C4} \right \} , \left \{ u \left ( x,t \right ) =-4\,{{\it \_C2}}^{2} \left ( \tanh \left ( -16\,{{\it \_C2}}^{5}t+{\it \_C2}\,x+{\it \_C1} \right ) \right ) ^{2}+8/3\,{{\it \_C2}}^{2} \right \} , \left \{ u \left ( x,t \right ) =-2\,{{\it \_C2}}^{2} \left ( \tanh \left ( {\it \_C2}\,x+{\it \_C3}\,t+{\it \_C1} \right ) \right ) ^{2}-1/15\,{\frac {-20\,{{\it \_C2}}^{3}+\sqrt {20\,{{\it \_C2}}^{6}-5\,{\it \_C3}\,{\it \_C2}}}{{\it \_C2}}} \right \} , \left \{ u \left ( x,t \right ) =-2\,{{\it \_C2}}^{2} \left ( \tanh \left ( {\it \_C2}\,x+{\it \_C3}\,t+{\it \_C1} \right ) \right ) ^{2}+1/15\,{\frac {20\,{{\it \_C2}}^{3}+\sqrt {20\,{{\it \_C2}}^{6}-5\,{\it \_C3}\,{\it \_C2}}}{{\it \_C2}}} \right \} \right \} \]

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36.26 Sine Gordon

problem number 220

Added December 27, 2018.

Taken from https://en.wikipedia.org/wiki/List_of_nonlinear_partial_differential_equations

Solve for \(u(x,t)\)

\[ \phi _{tt} - \phi _{xx} + \sin \phi = 0 \]

Mathematica

ClearAll[phi, x, t]; 
 pde = D[phi[x, t], {t, 2}] - D[phi[x, t], {x, 2}] + Sin[phi[x, t]] == 0; 
 sol = AbsoluteTiming[TimeConstrained[DSolve[pde, phi[x, t], {x, t}], 60*10]];
 

\[ \text {Failed} \]

Maple

 
phi:='phi';x:='x';t:='t'; 
pde:=diff(phi(x,t),t$2)-diff(phi(x,t),x$2)+sin(phi(x,t))=0; 
cpu_time := timelimit(60*10,CodeTools[Usage](assign('sol',pdsolve(pde,phi(x,t))),output='realtime'));
 

\[ \text { sol=() } \]

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36.27 Sinh Gordon

problem number 221

Added December 27, 2018.

Taken from https://en.wikipedia.org/wiki/List_of_nonlinear_partial_differential_equations

Solve for \(u(x,t)\)

\[ u_{xt} = \sinh u \]

Mathematica

ClearAll[u, x, t]; 
 pde = D[u[x, t], x, t] == Sinh[u[x, t]]; 
 sol = AbsoluteTiming[TimeConstrained[DSolve[pde, u[x, t], {x, t}], 60*10]];
 

\[ \text {Failed} \]

Maple

 
u:='u';x:='x';t:='t'; 
pde:=diff(u(x,t),x,t)=sinh(u(x,t)); 
cpu_time := timelimit(60*10,CodeTools[Usage](assign('sol',pdsolve(pde,u(x,t))),output='realtime'));
 

\[ \text { sol=() } \]

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36.28 Sinh Poisson

problem number 222

Added December 27, 2018.

Taken from https://en.wikipedia.org/wiki/List_of_nonlinear_partial_differential_equations

Solve for \(u(x,t)\)

\[ u_{xx}+u_{yy} + \sinh u=0 \]

Mathematica

ClearAll[u, x, y]; 
 pde = Laplacian[u[x, y], {x, y}] + Sinh[u[x, y]] == 0; 
 sol = AbsoluteTiming[TimeConstrained[DSolve[pde, u[x, y], {x, y}], 60*10]];
 

\[ \text {Failed} \]

Maple

 
u:='u';x:='x';y:='y'; 
pde:=diff(u(x,y),x$2)+diff(u(x,y),y$2)+ sinh(u(x,y))=0; 
cpu_time := timelimit(60*10,CodeTools[Usage](assign('sol',pdsolve(pde,u(x,y))),output='realtime'));
 

\[ \text { sol=() } \]

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36.29 Thomas equation

problem number 223

Added December 27, 2018.

Taken from https://en.wikipedia.org/wiki/List_of_nonlinear_partial_differential_equations

Solve for \(u(x,t)\)

\[ u_{xy} + \alpha u_x + \beta u_y+ \nu u_x u_y =0 \]

Mathematica

ClearAll[u, x, y, alpha, beta, nu]; 
 pde = D[u[x, y], x, y] + alpha*D[u[x, y], x] + beta*D[u[x, y], y] + nu*D[u[x, y], x]*D[u[x, y], y] == 0; 
 sol = AbsoluteTiming[TimeConstrained[DSolve[pde, u[x, y], {x, y}], 60*10]];
 

\[ \text {Failed} \]

Maple

 
u:='u';x:='x';y:='y';beta:='beta';alpha:='alpha';nu:='nu'; 
pde:=diff(u(x,y),x,y)+alpha*diff(u(x,y),x)+beta*diff(u(x,y),y) 
      +nu* diff(u(x,y),x)*diff(u(x,y),y)=0; 
cpu_time := timelimit(60*10,CodeTools[Usage](assign('sol',pdsolve(pde,u(x,y),'build')),output='realtime'));
 

\[ u \left ( x,y \right ) =-1/2\,{\frac {\sqrt {{\alpha }^{2}-2\,\alpha \,\beta +{\beta }^{2}-4\,{\it \_c}_{{1}}\nu }x}{\nu }}+1/2\,{\frac {\sqrt {{\alpha }^{2}-2\,\alpha \,\beta +{\beta }^{2}-4\,{\it \_c}_{{1}}\nu }y}{\nu }}-1/2\,{\frac {\sqrt {{\alpha }^{2}+2\,\alpha \,\beta +{\beta }^{2}-4\,{\it \_c}_{{1}}\nu }x}{\nu }}-1/2\,{\frac {\sqrt {{\alpha }^{2}+2\,\alpha \,\beta +{\beta }^{2}-4\,{\it \_c}_{{1}}\nu }y}{\nu }}-{\frac {\alpha \,y}{\nu }}-{\frac {\beta \,x}{\nu }}-2\,{\frac {\ln \left ( 2 \right ) }{\nu }}-1/2\,{\frac {1}{\nu }\ln \left ( {\frac {{\alpha }^{2}+2\,\alpha \,\beta +{\beta }^{2}-4\,{\it \_c}_{{1}}\nu }{{\nu }^{2} \left ( {\it \_C3}\,{{\rm e}^{2\, \left ( x/2+y/2 \right ) \sqrt {{\alpha }^{2}+2\,\alpha \,\beta +{\beta }^{2}-4\,{\it \_c}_{{1}}\nu }}}-{\it \_C4} \right ) ^{2}}} \right ) }-1/2\,{\frac {1}{\nu }\ln \left ( {\frac {{\alpha }^{2}-2\,\alpha \,\beta +{\beta }^{2}-4\,{\it \_c}_{{1}}\nu }{{\nu }^{2} \left ( {\it \_C1}\,{{\rm e}^{2\, \left ( x/2-y/2 \right ) \sqrt {{\alpha }^{2}-2\,\alpha \,\beta +{\beta }^{2}-4\,{\it \_c}_{{1}}\nu }}}-{\it \_C2} \right ) ^{2}}} \right ) } \]

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36.30 phi equation

problem number 224

Added December 27, 2018.

Taken from https://en.wikipedia.org/wiki/List_of_nonlinear_partial_differential_equations

Solve for \(u(x,t)\)

\[ \phi _{tt} - \phi _{xx} - \phi + \phi ^3 = 0 \]

Mathematica

ClearAll[u, x, y, alpha, beta, nu]; 
 pde = D[phi[x, t], t, t] - D[phi[x, t], x, x] - phi[x, t] + phi[x, t]^3 == 0; 
 sol = AbsoluteTiming[TimeConstrained[DSolve[pde, phi[x, t], {x, t}], 60*10]];
 

\[ \left \{\left \{\phi (x,t)\to -\tanh \left (c_2 t-\frac {\sqrt {2 c_2^2+1} x}{\sqrt {2}}+c_3\right )\right \},\left \{\phi (x,t)\to \tanh \left (c_2 t-\frac {\sqrt {2 c_2^2+1} x}{\sqrt {2}}+c_3\right )\right \},\left \{\phi (x,t)\to -\tanh \left (c_2 t+\frac {\sqrt {2 c_2^2+1} x}{\sqrt {2}}+c_3\right )\right \},\left \{\phi (x,t)\to \tanh \left (c_2 t+\frac {\sqrt {2 c_2^2+1} x}{\sqrt {2}}+c_3\right )\right \}\right \} \]

Maple

 
phi:='phi';x:='x';t:='t'; 
pde:=diff(phi(x,t),t$2)-diff(phi(x,t),x$2) - phi(x,t) + phi(x,t)^3=0; 
cpu_time := timelimit(60*10,CodeTools[Usage](assign('sol',{PDEtools:-TWSolutions(pde,phi(x,t))}),output='realtime'));
 

\[ \left \{ \left \{ \phi \left ( x,t \right ) =-1 \right \} , \left \{ \phi \left ( x,t \right ) =1 \right \} , \left \{ \phi \left ( x,t \right ) =-\tanh \left ( -1/2\,\sqrt {4\,{{\it \_C2}}^{2}-2}t+{\it \_C2}\,x+{\it \_C1} \right ) \right \} , \left \{ \phi \left ( x,t \right ) =-\tanh \left ( 1/2\,\sqrt {4\,{{\it \_C2}}^{2}-2}t+{\it \_C2}\,x+{\it \_C1} \right ) \right \} , \left \{ \phi \left ( x,t \right ) =\tanh \left ( -1/2\,\sqrt {4\,{{\it \_C2}}^{2}-2}t+{\it \_C2}\,x+{\it \_C1} \right ) \right \} , \left \{ \phi \left ( x,t \right ) =\tanh \left ( 1/2\,\sqrt {4\,{{\it \_C2}}^{2}-2}t+{\it \_C2}\,x+{\it \_C1} \right ) \right \} \right \} \]