Water brake dyno coupling
Water brake dyno coupling
(OP)
Just looking for some advie on an engine dyno I am trying to make. looking into alternative load devices, Water brake AC motor/invertor. Can anybody offer any advice on sourcing a water brake capable of around 170 HP ? Also can anybody offer some advice on the use of a fluid coupling converted to a water brake ? Any how to control the torque on such an item? Thanks in anticipation of some advice.





RE: Water brake dyno coupling
It's not as simple is just filling it with a controlled charge of water and sealing it up, because the water gets very hot very fast... so you have to circulate and cool it.
Mike Halloran
Pembroke Pines, FL, USA
RE: Water brake dyno coupling
You may also want to look into an eddy-current style absorber, but they (usually) still require water to cool them.
RE: Water brake dyno coupling
RE: Water brake dyno coupling
Mike Halloran
Pembroke Pines, FL, USA
RE: Water brake dyno coupling
RE: Water brake dyno coupling
RE: Water brake dyno coupling
Thanks in anticipation of your help>
RE: Water brake dyno coupling
Regards
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RE: Water brake dyno coupling
I hope I am not transgressing any Forum rules mentioning this, so will not give a direct link to e-bay.
Another resource is the Flow Bench and Dyno forum. There is a long thread there in the "dyno" section with a lot of pictures and technical info about home built water brakes.
htt
RE: Water brake dyno coupling
The amount of water in the dyno determines the torque resistance and the flowrate through the dyno is determined by the power (need to absorb XXX power so need YYY amount of water flowing through at a temperature difference of ZZZ). The water outlet temperature needs to be low enough to prevent the water in the dyno from flashing to vapour (some cavitation likely occurs though).
More advanced dynos use control valves on both the water inlet and outlet which I assume allows for a greater torque/power range to be accommodated.
RE: Water brake dyno coupling
Both the water level and the speed of the dyno determine how much torque resistance there is (you get more torque at a higher speed for a given water level). Once the dyno is full at a given speed you have maxed out its torque capacity. If you increase the engine speed you will then have to increase the flow rate through the dyno, while keeping it full, to keep the water temperature acceptable.
RE: Water brake dyno coupling
Bill
--------------------
"Why not the best?"
Jimmy Carter
RE: Water brake dyno coupling
We are talking about a water brake which is a water filled coupling with variable water level to control load. It is designed from day one to run in water.
Regards
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RE: Water brake dyno coupling
and again
Respectfully
Bill
--------------------
"Why not the best?"
Jimmy Carter
RE: Water brake dyno coupling
I should have reread the OP before commenting.
Regards
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RE: Water brake dyno coupling
Thanks
RE: Water brake dyno coupling
Anything made out of cast iron or mild steel will corrode at unbelievable speed with HOT water. Especially hot water that has any dissolved oxygen in it.
The hot water pipes in your home will only use copper or brass fittings. The cold water pipes may be iron if the house is old.
A water brake made from fairly thin pressed mild steel parts will not last very long. With oil, corrosion is a non issue.
RE: Water brake dyno coupling
Regards
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Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips Fora.
RE: Water brake dyno coupling