Why discuss energy and momentum?
Without discussing energy and momentum, I always think that the connection to the physics at work can be lost. Newton's laws deal with momentum conservation and input, Bernouilli's theorem deals with energy conservation and input. Both are necessary. Viscosity moves momentum around, and turbulence dumps energy, aided by viscosity. These processes add extra complexity to dealing with fluids, but don't take away from the need to conserve the normal stuff that needs conserving. If you jump to the Navier-Stokes equation, it includes everything you need, but doesn't immediately lend itself to intuitive explanation.
For whirlpools: try spinning a tall perspex tube filled with water along its axis: as it speeds up, the surface dips in the centre, and a thread of air can go right to the bottom. The tube can be huge. There's one that's at least 12 feet high at Techniquest on the Cardiff waterfront. You can see it on their virtual tour.