https://en.wikipedia.org/wiki/Hydraulic_macroeconomics
Vladimir Lukyanov's hydraulic computer - https://news.ycombinator.com/item?id=18525534 - Nov 2018 (72 comments)
Kind of related but not directly:
MONIAC – Monetary National Income Analogue Computer - https://news.ycombinator.com/item?id=18843255 - Jan 2019 (6 comments)
The Water Computer (2016) - https://news.ycombinator.com/item?id=18846599 - Jan 2019 (26 comments)
MONIAC, a hydraulic computer that modeled the economy - https://news.ycombinator.com/item?id=9812721 - July 2015 (6 comments)
MONIAC: an analogue computer using fluidic logic to model an economy. - https://news.ycombinator.com/item?id=4438081 - Aug 2012 (1 comment)
https://www.andrew.cmu.edu/user/kk3n/80-300/madlin1989.pdf
https://wiki.lspace.org/Glooper
https://en.wikipedia.org/wiki/Hydraulic_macroeconomics