Simplifying a Boundary Layer Theory Equation

AI Thread Summary
The discussion focuses on simplifying a boundary layer theory equation, specifically transforming the equation dΨ/dy(d²Ψ/dxdy) - dΨ/dx(d²Ψ/dy²) = -ν(d³Ψ/dy³) into the form -ff'' = f'''. The variable Ψ is defined as Ψ(x,y) = -√(Vνx)f(η), where f(η) is the integral of (Π')*(η̅) with respect to the dummy variable η̅. Participants in the thread express difficulties in taking derivatives using Maple software to achieve the desired form. The original equation stems from the Navier-Stokes equations, with a substitution made for the stream function. The conversation emphasizes the need for clarity in mathematical formatting and notation throughout the problem-solving process.
juice34

Homework Statement


The problem is write this

d\Psi/dy(d^2\Psi/dxdy)-d\Psi/dx(d^2\Psi/dy^2=-\nu(d^3\Psi/dy^3)

in the form of -ff''=f'''
where

\Psi(x,y)=-sqrt(V*\nu*x)f(\eta)

f(\eta)=integral(from 0 to \eta)(\Pi')*(\overline{\eta})*d(\overline{\eta}) where \overline{\eta} is a dummy variable

Homework Equations

\prod

The Attempt at a Solution


I have just tried taking the derivatives using maple but to no avail. Please help! Also note that the small v is a multiplier and nothing is raised to the power. Please excuse my formatting.
 
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also note initally the first equation was the navier stokes equation, then i substituted in the stream function.
 
Finally got the solution
 
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