CFD Online Discussion Forums - WALE model definition !?

Hello,

I'm trying to implement WALE model in LES code using Fortran for channel flow.
Now the model definition for sgs viscosity is:

$\nu_{\tau}$ = $\Delta^2_{s}$ $\frac{\left(S^d_{ij}S^d_{ij}\right)^{3/2}}{\left(\bar{S}_{ij}\bar{S}_{ij}\right)^{3/2}+\left(S^d_{ij}S^d_{ij}\right)^{5/4}}$

where, $S^d_{ij}S^d_{ij}$ = $\frac{1}{6}\left(S^{2}S^{2} + \Omega^{2}\Omega^{2}\right)+\frac{2}{3}S^{2}\Omega^{2} + 2(IV)_{S\Omega}$

$S^2 = \bar{S}_{ij}\bar{S}_{ij}$
$\Omega^2 = \bar{\Omega}_{ij}\bar{\Omega}_{ij}$
$(IV)_{S\Omega} = \bar{S}_{ik}\bar{S}_{kj}\bar{\Omega}_{jl}\bar{\Omega}_{li}$

I'm having problems understanding the last term in the above equation $\left(\bar{S}_{ik}\bar{S}_{kj}\bar{\Omega}_{jl}\bar{\Omega}_{li}\right)$ .
Can anyone please explain how to expand the above term?

Cheers