Versions Compared

Key

  • This line was added.
  • This line was removed.
  • Formatting was changed.

...

Info
titleCalculating Time Step Size
Wiki Markup
The Strouhal number for flow past cylinder is roughly 0.183 as reported by Williamson (link).
\\
In order to capture the shedding correctly, we should have at least 20 to 25 time steps in one shedding cycle. Let's use 25 for our case.
{latex}
\large
$$
{\rm{Sr}} = {fD \over U} = 0.183
$$
{latex}
For our case, *D = 2, U = 1*
\\
Therefore, shedding frequency *f = 0.0915*
\\
Cycle time,

{latex}
\large
$$
{\rm{t}} = {1 \over f} = 10.9 sec
$$
{latex}

*t = 1/f = 10.9 sec*
\\
Therefore, *Time Step Size = 10.9/25 = 0.436 sec*

...