I'm a Surfer Dude …Really
I'm a Surfer Dude "¦Really
Since there are lots of people looking at this just for fun and since you haven't settle on a way forward, I thought that I would throw in another wild thought.
That's not me in the picture.
I can't say that I haven't seen something close to this before but when I saw those waves splashing up into the air, I thought of when I learned to surf in Phoenix. Yes Phoenix Arizona.
They built a giant wall several stories tall. When paddling close to it, it looked like a building. It was filled it with massive pumps and then they let all the water go at once through big gates at the bottom of the wall. In that respect, it was like a toilet reservoir.
About 12 feet from the gates, there was another wall, well below the water line, that the rushing water ran into. This created a vertical volume of water that lifted me straight up about 6 feet to start my surfing wave that I rode to the beach.
Let's say you built a rectangular plunger, the width of the side box and the length of the tank from front to back. Then you moved it up and down with the piston, rod and crank style mechanism. This being driven by a geared motor so it would have lots of steady power. You have another unit at the other side with opposed timing but on the same shaft. You could play with where on the wheel the rods were attached to change the drive timing encase you wanted to change the timing of the force. The unwanted vertical wave action might be dampened by taking the second drive plunger slightly out of phase. (In the bottom of the picture, you can see the piston, rod and crank idea being straightened out so it wouldn't need the wall of the cylinder to keep it straight. In the next two graphics, you see how a standard placement of the rods could be and the last two are there to show how they could be moved while tuning, to change the timing of the second stroke.)
Then you use some of those curved louvers like in the big wave machine to redirect the flow across the tank. I think that these louvers could be pretty easy to make with limited tools and skills but I will skip how since this is just an idea.
Just like the paddles, the plungers would not use a seal but have a close, non-touching fit. Water that blows past the plunger would collect and run off at the top of the stroke and return to the tank. This leakage could also serve to maintain the vacuum action of the upward stroke so that it might be able to go well above the water line of the main tank. This way, you could have a longer stroke for more displacement.
I THINK that a straight section may be over rated because ripples, like burbling after an airplane wing, would dampened faster than in air and be minimized because of the density of water. Up and down motion would quickly die (I THINK) and the stream would become laminar enough.
