Nomenclature: Difference between revisions

From Atomix
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| <math>\hat{k}_n</math>
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| Nyquist wavenumber, based on sampling volume's size <math>\Delta l</math>
| Nyquist wavenumber, based on sampling volume's size <math>\Delta l</math>
| <math>\hat{k}_n=\frac{0.5}{\Delta l}</math>
| <math>\hat{k}_\Delta=\frac{0.5}{\Delta l}</math>
| cpm
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Revision as of 14:33, 12 March 2021

Frame of reference

  • Define frame of reference, and notation. Use u,v,w and x,y, and z?
  • Decomposition of total, mean, turbulent and waves.


Turbulence Spectrum

Taylor's Frozen Turbulence for converting temporal to spatial measurements [math]\displaystyle{ \left(\bar{u}_1\frac{\partial }{\partial{x}} = \frac{\partial}{\partial{t}}\right) }[/math]


Symbol Description Eqn Units
[math]\displaystyle{ \epsilon }[/math] Turbulent kinetic energy dissipation W/kg
[math]\displaystyle{ f }[/math] Frequency [math]\displaystyle{ \frac{\omega}{2\pi} }[/math] Hz
[math]\displaystyle{ f_n }[/math] Nyquist frequency [math]\displaystyle{ f_n=0.5f_s }[/math] Hz
[math]\displaystyle{ f_s }[/math] Sampling frequency [math]\displaystyle{ \frac{1}{\Delta t} }[/math] Hz
[math]\displaystyle{ k }[/math] Wavenumbers (angular) [math]\displaystyle{ k=\frac{f}{\bar{u}} }[/math] rad/m
[math]\displaystyle{ \hat{k} }[/math] Wavenumbers [math]\displaystyle{ \frac{k}{2\pi} }[/math] cpm
[math]\displaystyle{ \hat{k}_\Delta }[/math] Nyquist wavenumber, based on sampling volume's size [math]\displaystyle{ \Delta l }[/math] [math]\displaystyle{ \hat{k}_\Delta=\frac{0.5}{\Delta l} }[/math] cpm
[math]\displaystyle{ \Delta t }[/math] Sampling interval [math]\displaystyle{ \frac{1}{f_s} }[/math] s
[math]\displaystyle{ \omega }[/math] Angular frequency [math]\displaystyle{ 2\pi f }[/math] rad/s