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docs:utils:fieldprops [2009/03/22 09:16]
gibson created
docs:utils:fieldprops [2009/03/22 09:37]
gibson
Line 3: Line 3:
 print out basic properties of a FlowField print out basic properties of a FlowField
  
 +<​code>​
 +options :
 +  -g        --geometry ​                                            show geometrical properties
 +  -m        --mean ​                                                show mean properties
 +  -n        --norm ​                                                show norm properties
 +  -sp       ​--spectral ​                                            show spectral properties
 +  -sy       ​--symmetry ​                                            show symmetry properties
 +  -d        --dynamic ​                                             show dynamical properties
 +  -e        --energy ​                                              show energy properties
 +  -R        --Reynolds ​         <​real> ​     default == 400         ​Reynolds number
 +  -eps      --eps               <​real> ​     default == 1e-07       ​spectral noise floor
 +  -dt       ​--dt ​               <​real> ​     default == 0.03125 ​    ​integration time for du/dt estimate
 +  -T        --T                 <​real> ​     default == 0.03125 ​    ​integration time for du/dt estimate
 +  -nl       ​--nonlinearity ​     <​string> ​   default == rot         ​method for  u grad u [rot or skw]
 +  -dg       ​--digits ​           <​int> ​      ​default == 6           ​digits of output for reals
 +  <​flowfield> ​     (trailing arg 1)                                input field
 +</​code>​
  
 +Definitions:​ The norms and energy measures reported by the -n and -e options are defined as follows
 +
 +<​latex>​ $ \begin{align*}
 + ​\text{L2Norm} \quad   ​\|u\| ​ &= \left(\frac{1}{L_x L_y L_z} \int_{\Omega} \|{\bf u}\|^2\,\, d{\bf x} \right)^{1/​2}\\
 + ​\text{energy} \quad   E(u) &= \frac{1}{2 L_x L_y L_z} \int_{\Omega} \|{\bf u}\|^2\,\, d{\bf x}  \\
 + ​\text{dissipation} ​ \quad  D(u) &= \frac{1}{L_x L_y L_z} \int_{\Omega} \|\nabla \times {\bf u}\|^2 \,\, d{\bf x} \\
 + ​\text{forcing} ​ \quad  I(u) &= \frac{1}{L_x L_z} \int_{y=a,​b} \frac{\partial u}{\partial y} \, dx dz
 +\end{align*} $ </​latex>​
 +
 +FIXME: Some of the measures output by fieldprops assume that the field is the fluctuating velocity field 
 +of plane Couette flow, and some quantities are reported for the total velocity field %%u+U%% where %U(y) = y%%.
 +There should be an option for specifying other common base-flow / fluctuation decompositions,​ or none.
docs/utils/fieldprops.txt ยท Last modified: 2010/02/02 07:55 (external edit)