Two examples of vigorous liquid motion that can obviously do mechanical work, e.g. by rotating a waterwheel:

https://www.youtube.com/watch?v=MUWvQYoPDVg

https://www.youtube.com/watch?v=hr76wCqq_4k

The liquid motion is powered by thermal energy, so the mechanical work will be done at the expense of ambient heat, in violation of the second law of thermodynamics.

The phrase "in violation of the second law of thermodynamics" precludes any relevant research. Scientists would not even think in this direction:

George Orwell: "Crimestop means the faculty of stopping short, as though by instinct, at the threshold of any dangerous thought. It includes the power of not grasping analogies, of failing to perceive logical errors, of misunderstanding the simplest arguments if they are inimical to Ingsoc, and of being bored or repelled by any train of thought which is capable of leading in a heretical direction. Crimestop, in short, means protective stupidity."

Pentcho Valev https://twitter.com/pentcho_valev

"The potential implications of second law research are obvious. What is at stake is virtually all the energy in the world. The total thermal energy content of the atmosphere, ocean, and upper crust is estimated to be 10,000 times greater than that of known carbon fuel and fission fuel reserves. In quantity, the energy stores of thermal energy are almost boundless and, because second-law–violating devices allow conversion of waste heat back into work over and over again without limit, the energy stores can be considered effectively infinite. If environmental heat can be economically converted into useful work on a wide scale—electrical, mechanical, chemical—the effects on the energy sector, the global economy, societal and ecological welfare, warfare, and virtually all aspects of civilization and its relationship to Nature are difficult to predict, but they are likely to be profound—and, we hope, mostly salutary. Of course, every technology is two-edged, depending on its application. In light of second law developments since the mid1990s, now might seem a good time to start preparing for a world in which thermal energy will be the coin of the realm." https://philpapers.org/rec/HATSEA-4

No, say thermodynamicists. Don't start preparing for anything if you wish to avoid deepest humiliation:

Arthur Eddington: "The law that entropy always increases—the Second Law of Thermodynamics—holds, I think, the supreme position among the laws of Nature. If someone points out to you that your pet theory of the universe is in disagreement with Maxwell’s equations—then so much the worse for Maxwell’s equations. If it is found to be contradicted by observation—well these experimentalists do bungle things sometimes. But if your theory is found to be against the second law of thermodynamics I can give you no hope; there is nothing for it but to collapse in deepest humiliation." https://todayinsci.com/E/Eddington_Arthur/EddingtonArthur-Entropy-Quotations.htm

Pentcho Valev https://twitter.com/pentcho_valev

Pentcho Valev <pvalev@yahoo.com> wrote:

[-]
> Arthur Eddington: "The law that entropy always increases—the Second Law of
> Thermodynamics—holds, I think, the supreme position among the laws of
> Nature. If someone points out to you that your pet theory of the universe
> is in disagreement with Maxwell's equations—then so much the worse for
> Maxwell's equations. If it is found to be contradicted by observation—well
> these experimentalists do bungle things sometimes. But if your theory is
> found to be against the second law of thermodynamics I can give you no
> hope; there is nothing for it but to collapse in deepest humiliation."

FYI, you have collapsed, and been humiliated.
Learn to live with it,

Jan

In order to be able to work on a perpetual motion machine of the second kind, you have to pathetically wriggle in the following way (otherwise fierce thermodynamicists may mercilessly destroy your career):

Physicists Build Circuit That Generates Clean, Limitless Power From Graphene "A team of University of Arkansas physicists has successfully developed a circuit capable of capturing graphene's thermal motion and converting it into an electrical current. “An energy-harvesting circuit based on graphene could be incorporated into a chip to provide clean, limitless, low-voltage power for small devices or sensors,” said Paul Thibado, professor of physics and lead researcher in the discovery...Though the thermal environment is performing work on the load resistor, the graphene and circuit are at the same temperature and heat does not flow between the two. That’s an important distinction, said Thibado, because a temperature difference between the graphene and circuit, in a circuit producing power, would contradict the second law of thermodynamics. “This means that the second law of thermodynamics is not violated, nor is there any need to argue that ‘Maxwell’s Demon’ is separating hot and cold electrons,” Thibado said." https://news.uark.edu/articles/54830/physicists-build-circuit-that-generates-clean-limitless-power-from-graphene

Paul Thibado Jan 22 2022, SSE Special Session, Advanced Propulsion & Energy IV https://youtu.be/cFO32QWJe1c?t=2106
"Where does the stored capacitor energy come from? Work is done by thermal surroundings.
Is useful work done at a single temperature? Yes, everything is at the same temperature, T (isothermal process).
Does our system violate the second law of thermodynamics? No.
Is entropy produced? Yes."

Pentcho Valev https://twitter.com/pentcho_valev

Pentcho Valev <pvalev@yahoo.com> wrote:

> "The potential implications of second law research are obvious. What is at
> stake is virtually all the energy in the world. The total thermal energy
> content of the atmosphere, ocean, and upper crust is estimated to be
> 10,000 times greater than that of known carbon fuel and fission fuel
> reserves. In quantity, the energy stores of thermal energy are almost
> boundless and, because second-law–violating devices allow conversion of
> waste heat back into work over and over again without limit, the energy
> stores can be considered effectively infinite.

Now there you have gotten something right for once.
Since the prospect of infinite free energy,
and for ever reusable too, is obviously absurd
those evil thermodynamicists have made it an axiom
that it is impossible.
And they went on, together with the first law,
to build the whole science of thermdynamics on it,
as an axiomatic structure.

So there you have it, just like the first law,
it is 'nothing but' an axiom.
Just take another axiom, and start producing unlimited free energy.
No excuses, no one forbids you to, go ahead and do it,

Jan
(not holding my breath)