# Help me solving this differential equation please

by ahm_11
Tags: differential, equation, solving
 P: 6 μ[uyy + uzz] - ∂p/∂x = 0 ... (1) ∂u/∂x = 0 ; i tried assuming u(y,z) = Y(y)Z(z) so (1) becomes ... μ[ZYyy + YZzz] - ∂p/∂x = 0 hence (1/Y)*Yyy + (1/Z)*Zzz = (R/YZ) = -λ2 where, R = (1/μ)*∂p/∂x now Yyy + λ2Y = 0 ... can be solved easily but what about the remaining part .... i couldn't solve it due to the constant ...
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P: 21,321
 Quote by ahm_11 μ[uyy + uzz] - ∂p/∂x = 0 ... (1) ∂u/∂x = 0 ; i tried assuming u(y,z) = Y(y)Z(z) so (1) becomes ... μ[ZYyy + YZzz] - ∂p/∂x = 0 hence (1/Y)*Yyy + (1/Z)*Zzz = (R/YZ) = -λ2 where, R = (1/μ)*∂p/∂x now Yyy + λ2Y = 0 ... can be solved easily but what about the remaining part .... i couldn't solve it due to the constant ...
Is there any other information? In particular, is there anything known about p?
 P: 6 ∂p/∂x = constant Some boundary conditions: x=0 , x=L ..... ∂u/∂x = 0 , v=0 , w=0 , ∂p/∂x = constant y=-a,y=a ..... u=0,v=0,w=0, ∂p/∂y=0 z=-b,z=b ..... u=0,v=0,w=0, ∂p/∂z = 0
HW Helper
Thanks
P: 5,091
Help me solving this differential equation please

 Quote by ahm_11 μ[uyy + uzz] - ∂p/∂x = 0 ... (1) ∂u/∂x = 0 ; i tried assuming u(y,z) = Y(y)Z(z) so (1) becomes ... μ[ZYyy + YZzz] - ∂p/∂x = 0 hence (1/Y)*Yyy + (1/Z)*Zzz = (R/YZ) = -λ2 where, R = (1/μ)*∂p/∂x now Yyy + λ2Y = 0 ... can be solved easily but what about the remaining part .... i couldn't solve it due to the constant ...
Since $\partial{p}/\partial{x} = c$ (a constant) your DE is just
$$u_{yy} + u_{zz} = k,$$
where $k = c/ \mu$ is a constant. Your condition $u_x = 0$ means that 'x' does not appear anywhere in the problem.

RGV

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