Recent content by Bianca123

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    Finding Solutions for Coupled ODEs with Constant Parameters

    Okay, thank you for replies:D
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    Finding Solutions for Coupled ODEs with Constant Parameters

    I have also the same as you, only not with the identity matrix on the left side( do I need this?) and with a²b²-Ra on the left bottom in the matrix. I think it is correct with minus instead of plus(like you have). Then I get the following eigenvalues and eigenvectors:Squareroot= SQ λ1=SQ(α²*b²...
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    Finding Solutions for Coupled ODEs with Constant Parameters

    I see now that in my first thread I miss the derivative sign on the G, it is suppose to be (Ra/b³) *G' ! So the system I have written in my latest thread(the one over here) is the correct one!
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    Finding Solutions for Coupled ODEs with Constant Parameters

    So my system is F'' - (α^2 * b^2 * F ) = (Ra / b)*G' G'' - (α^2 * b^2 +Ra)*G = F'*bIf I say that F'=H and G'=I, I have the following system: F'=H G'=I H' - α^2*b^2*F = (Ra/b)*I I' - (α^2*b^2 - Ra)*G =b*HIf I write my system as a matrix looking like: x'=Ax, I have: F' 0...
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    Finding Solutions for Coupled ODEs with Constant Parameters

    Svein: Yes, what you suggested is correct Bigfooted: Yes it is the system then The_wolfman: I have tried your solutions but cannot solve it that way. I have read some other similar papers where their soulution to both F and G are functions of sinh and cosh, but I cannot seem to find such a...
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    Finding Solutions for Coupled ODEs with Constant Parameters

    Hello :)I have a system which consists of two coupled ODEs for which I want to solve.F'' *(1/b²) - α²*F = Ra*(1/b³)*G G'' *(1/b²) - α*²G + Ra*(1/b²)*G = F'(1/b) In these two equations F(z) and G(z) both depend on z. b is a constant, Ra is the rayleigh number which I need to keep as Ra in my...
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    How to get rid of laplace of pressure in an equation

    No it is not a homework, it is my master thesis. In order to write out the system in a 8x8-matrix I need all the variables in T. Top and bottom of the cylinders are impermeable and perfectly heat conducting. The sidewalls are impermeable and insulated. I am to see how natural convection cells...
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    How to get rid of laplace of pressure in an equation

    I am looking at natural convection between two coaxial cylinders. Between them there are to layers of different height and permeability, which I will change in my calculations and see how this effects my solution. Originally, after doing a permutation to the steady state solution, and after...
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    How to get rid of laplace of pressure in an equation

    Hello! I have a question about an equation. I have an equation which is a boundary condition to a problem I have concerning fluid flow in a layered porous medium. I have a equation where my only variable is the temperature T, and I have 10 boundary conditions with it. In order to solve the...
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