Relations involving stream-wise velocity

Differentiations

\[\sumzc \sumyf \sumxc \vel{2} \dif{q}{\gcs{1}} = - \sumzc \sumyf \left( \vat{\left(\vel{2} q\right)}{\frac{1}{2}} + \sumxf \dif{\vel{2}}{\gcs{1}} q - \vat{\left(\vel{2} q\right)}{\ngp{1} + \frac{1}{2}} \right).\]
\[\sumzc \sumyf \sumxc \vel{2} \dif{q}{\gcs{2}} = - \sumzc \sumyc \sumxc \dif{\vel{2}}{\gcs{2}} q.\]
\[\sumzc \sumyf \sumxc \vel{2} \dif{q}{\gcs{3}} = - \sumzf \sumyf \sumxc \dif{\vel{2}}{\gcs{3}} q.\]

Averages

\[\sumzc \sumyf \sumxc \vel{2} \ave{q}{\gcs{1}} = \sumzc \sumyf \left( \vat{\vel{2}}{1} \frac{\vat{q}{\frac{1}{2}}}{2} + \sum_{i = \frac{3}{2}}^{\ngp{1} - \frac{1}{2}} \ave{\vel{2}}{\gcs{1}} q + \vat{\vel{2}}{\ngp{1}} \frac{\vat{q}{\ngp{1} + \frac{1}{2}}}{2} \right).\]
\[\sumzc \sumyf \sumxc \vel{2} \ave{q}{\gcs{2}} = \sumzc \sumyc \sumxc \ave{\vel{2}}{\gcs{2}} q.\]
\[\sumzc \sumyf \sumxc \vel{2} \ave{q}{\gcs{3}} = \sumzf \sumyf \sumxc \ave{\vel{2}}{\gcs{3}} q.\]