Zero-shear lower wall in a translating and squeezing finite gap
= Zero-shear lower wall in a translating and squeezing finite gap
The horizontal force on the lower wall vanishes when
$$
U=6V\frac{
\langle xh^{-2}\rangle
-\langle h^{-2}\rangle\langle xh^{-3}\rangle/
\langle h^{-3}\rangle}
{4\langle h^{-1}\rangle
-3\langle h^{-2}\rangle^2/\langle h^{-3}\rangle}.
$$