Recent content by shreddinglicks

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    A The heat equation for a composite having contact resistance

    I guess I see what you mean. So the heat is diffusing to left and right causing the hump I'm seeing with that left curve.
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    A The heat equation for a composite having contact resistance

    I followed what you said. I checked my solution over more than once. I derived the solution for a non-homogeneous problem with the external boundaries at constant temperature. I don't like the curve I have on the left. There is a weird hump in it. The image shows a graph from MATLAB at t=1...
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    A The heat equation for a composite having contact resistance

    By time evolution you mean the thermal diffusivity has to be in the spatial equation?
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    A The heat equation for a composite having contact resistance

    With a quick online search I see that most sources state that the boundary condition at the interface of two materials in contact having contact resistance is -ksub1*u'sub1 = -ksub2*u'sub2 =q usub1 - usub2 = R*q I've tried to produce a solution consisting of two equations, each describing the...
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    Finding the natural frequency of a pipe with two 90 degree bends

    Thanks for the responses. I'll respond back with my attempts.
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    Finding the natural frequency of a pipe with two 90 degree bends

    I have FEA results for this. I'm trying to see if this problem can be solved by hand with reasonable accuracy.
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    Finding the natural frequency of a pipe with two 90 degree bends

    Interesting. I have FEA results for this problem. I wanted to see if there was a way to get the solution using a pencil and paper. I'll try what you have here and see what I get.
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    Finding the natural frequency of a pipe with two 90 degree bends

    But what about a pipe of this shape being broken up into three pieces. Two cantilevers and one pin-pin. Is it possible to sum the individual natural frequencies to get the frequency of the entire pipe? Does plane matter if the natural frequency is scalar?
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    Finding the natural frequency of a pipe with two 90 degree bends

    I'm trying to find the natural frequency of a pipe that is roughly z shaped (two 90 degree bends). Is it possible to break this pipe up into three straight pieces and model each piece as a beam experiencing transverse vibration? For example, modeling the end segments as cantilevers and the...
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    How do I solve the Laplace equation using Robbin's Boundary Conditions?

    Yes, exactly as you said. du/dx and h is a constant. I realized I made an error. The conditions are actually I'll fix it also on the original post. It's what you have but y instead of x. The problem is, this gives an answer where for all y when u(0,y)=0 when x should be zero, x does not...
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    How do I solve the Laplace equation using Robbin's Boundary Conditions?

    I've tried a few things. I did one method to try to accomplish the removal of the -70 in the derivative boundary condition. It came out as below. When plotting it however it gave a solution that didn't make sense.
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    A Heat conduction equation in cylindrical coordinates

    Interesting. I tried to apply what is shown in 11.4.2. How would I solve for A and B that is shown in 11.4.1?
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    A Heat conduction equation in cylindrical coordinates

    I've been studying a few books on PDE's, specifically the heat equation. I have one book that covers this topic in cylindrical coordinates. All the examples are applied to a solid cylinder and result in a general Fourier Bessel series for 3 common cases that can be found easily with an online...
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    Determining Thorium requirements for conversion reactor

    Let's say it's a light water reactor fueled by uranium 233. The goal is to convert enough uranium 233 from Thorium 232 to breakaway from uranium 235. So a conversion rate of 1 or slightly over 1.
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