Does All Gravitational Energy in Water Convert to Heat?

[flatmaster]

I am writing an intro physics problem about a flowing stream. I am going to assume that all of the gravitational potential energy eventually becomes thermal energy of the water. I haven't worked it yet, but I'm pretty sure the flow rate and g will both cancel out and give me a constant change in temperature per unit of elevation change.

Is there a specific name for this phenomenon?

How reasonable of an assumption is this? Some energy must go into eroding rock, making noise, etc.

 

[olivermsun]

I'm not sure which phenomenon you're specifically trying to name. Turbulent dissipation? Turbulent heating?

It doesn't seem that unreasonable for an "idealized" problem. In real life you would have some competing effects that would probably overwhelm the turbulent heating, including the gain in kinetic energy of the stream flow and heat exchange between the stream and the surroundings (especially the atmosphere which also tends to warm with decreasing elevation).

And sure, some energy might be lost to eroding/heating rocks, radiate away as acoustic or seismic waves to eventually heat something else, etc.