Phase Angle in Vortex-Induced Vibrations

Dear Matlab community,

I'm having problems when trying to calculate and plot the phase angle of a cylinder undergoing Vortex-Induced Vibrations.

I need to plot the following (just the solid black line):

(From: A Single Van Der Pol Wake Oscillator Model For Coupled Cross-Flow And In-Line Vortex-Induced Vibrations (Qu and Metrikine, 2020)).

I know this is a very specific question, but I already tried inumerous phase angle's functions that I found in the Matlab community, but nothing seems to work for me.

If anyone have the answer and/or a suggestion, I would be really grateful.

Thank you,

Rafael F.

[ZHI CHENG]

Hi, do you solve the problem, I am also interested in the Vortex-Induced Vibrations with wake oscillator.

Thanks!

[Rafael Fehér]

Hi, Cheng. Unfortunatelly, I didn't solve it yet. But if you wanna talk about VIV base on wake oscillators, please write me to: [e-mail]

It will be nice to have someone to trade information and ideias about this subject.

Answer 1

[Jon]

If you have phase angle values theta and velocity values v you can just plot

plot(v,theta)

If you are asking how do you calculate values of theta given v (that is theta is unknown) then this is a fluid mechanics question not a MATLAB question.

Please further specify what it is that you know and what problem you are having using MATLAB to solve it