fail.....
you need to maximize the surface area and create turbulence, this gives you 'mixing' events inside the liquid and increases your cooling

What might work is something like a miniature heatsink fins fixed to the bottom plate with the top plate fitting over them so that there are fins inside your flow channel, that would maximize your surface area.

Heat is absorbed by the bottom plate, into the fins, which then have the water swirling about them.