[Harmohit]

If we define a computer in very broad terms: a system used to emulate/simulate another system, could we call a wind tunnel a computer? It is a system that is used to infer what would happen high up in the atmosphere or on the race track. Taking it a step further, do animals used for drug testing count as computers? They are used to infer any potential adverse effects in a human body.

Although quite specialized, I think these things would still classify as a computer.

[GTP]

I think it would make more sense to limit the analysis to technologies that let you build a Turing-complete machine, but indeed sometimes you find people counting your examples as computers, because they are computing a specific function.

[OscarCunningham]

That's assuming that wind tunnels are not Turning-complete. Terry Tao has this fantastic idea of proving the Navier-Stokes equations blow up by proving the existence of a 'fluid computer'. https://terrytao.wordpress.com/2019/05/31/searching-for-sing...