[Cathar]

I posted this over at OCAU. Figured some of you guys might be interested:

Okay, I've decided to relent and post some piccies I snapped today of part of the block in action, being the jet acceleration stage of the block. I spent a lot of time tweaking and refining the block to get this level of pressure -> velocity transition taking place.

In general the jets are converting most centrifugal pumps' pressure into velocity to a point that is between 80-90% of the peak possible jet velocity achievable with that pump. Increasing restriction/velocity beyond the point I selected saw overall flow rates start to drop away very rapidly with very minimal gains in water velocity. As flow-rates drop, so does the thermal capacity of the water per unit time. Much juggling with calculated and predicted heat transfer co-efficients, pressure drops, pump PQ curves, and pressure-drop considerations of other components in a water-cooling loop, saw me settle on a point that I believe is as close to a one-size-fits-all balance point as is possible.

The jet intakes were carefully tweaked in a cost/machining effective fashion to provide a highly efficient level of pressure drop into the acceleration jets. In terms of flow rates with a given pump, and taking into account the rest of the block's resistance, it was calculated that perfect jet intakes would be unlikely to boost flow rates by more than a further 2-3%, so overall I was pretty happy with the compromise.

Okay, enough of the babble, here's the piccies:

For a frame of reference, the block is being held at a measured 1.5m above the ground, and where the water is hitting the ground is a measured 5.5-6.0m away. The pump being used was the Iwaki MD-30RZ (50Hz power).

No Flash:



With Flash:



Gratuitous fountain shot. Fountain reaches around 3m into the air.