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August 22, 2011, 07:31 

#21  
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Daniel
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Quote:
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The pressure ansatz is harmonic, and so is the velocity... For systolic wave forms you might find something helpful in the papers from METTE OLUFSEN... Cheers Daniel 

August 22, 2011, 07:33 

#22  
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Daniel
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Quote:
Quote:
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The pressure ansatz is harmonic, and so is the velocity... For systolic wave forms you might find something helpful in the papers from METTE OLUFSEN... Cheers Daniel 

October 11, 2011, 08:00 

#23 
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Michael Stiehm
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Hallo,
I am very interested in oscillating and pulsatile inletBC, so this is a great thread...thanks for that. But I have two questions: 1: Where did you get the Womersley Solution for the real part (post 16 and 17)? 2: When you have got this solution, is there still an need to solve the basic womersley solution with bessel function for complex numbers? Because the real part solution looks very nice!! Thanks a lot Michael Last edited by miael; October 12, 2011 at 10:14. 

November 14, 2011, 05:09 

#24  
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the shown equation is derived for a 2D channel and not for a 3D pipe. Although, you have nice pulsatile effects the flow rate is a sinus if you integrate it. to get a flow rate which composes of multiple sinus and cosinus functions, the complex womersley equation is necessary. 

March 11, 2012, 15:37 

#25 
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juanjo rivera
Join Date: Jan 2010
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Nihil,
Are you finished the implementation of the Womersley BC for velocity?. Can you show one example? I am interesting to implement it but in function of flow rate, not pressure gradient. 

March 19, 2012, 09:13 

#26 
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Michael Stiehm
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Hello Juanjo,
perhabs I can help you with your womersleyproblem. I used an octaveroutine to calculate the womersleyprofile. There you have no problem with komplex bessel functions. So you can calculate your velocity field for every time step you wanna use. Additional you have to create a points file (see tutorial) and then use the BC timeVaryingMappedFixedValue. I got good results with that. Hope I could help. Michael 

June 23, 2012, 22:42 
womersley

#27  
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Guifan Li
Join Date: Apr 2011
Location: New York City, U.S.
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Quote:
I am working on the Womersleyproblem for a while and I still didn't work out a good solution. It sounds like you put the Womersley equation with complex bessel function into octave which is quite amazing. But how do you store the data ( velocity at different location for a 3D case)? Btw, did you use the same equation below? Thanks 

June 25, 2012, 04:10 

#28 
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Michael Stiehm
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Hello,
yes this is the equation I use. If you want to calculate the womersleyprofile in octave you need the function besselj(0,...) for the complex besselfunction. So you get the womersleyprofile u(r,t) for a 2D case. Because of axissymmetric condition you can use the relationship r=sqrt(x^2+y^2) to calculate the 3D velocity field. As inlet BC I use timeVaryingMappedFixedValue therefore a file called points is required which contains the coordinates and for every time step you need a velocity file which contains the velocity field regarding to the "point" file. Regards Michael 

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