Attempt at a theory of the friction of fluids

TL;DR

Euler's 1754 treatise explores fluid friction, proposing it is proportional to normal force, and analyzes fluid discharge problems with applications to fountain jet heights.

Contribution

First systematic analysis of fluid friction proportionality and detailed discharge problem solutions based on Euler's early work.

Findings

Fluid friction proportional to normal force.

Detailed solutions for fluid discharge problems.

Application to fountain jet height calculations.

Abstract

This is a translation from Latin to Portuguese of Euler's 'Attempt at a theory of the friction of fluids'. According to the records, a treatise by Euler with the title 'Tentamen theoriae de frictione fluidorum' was presented to the St. Petersburg Academy on June 17, 1754, and perhaps was read to the Berlin Academy on December 2, 1751. In this treatise, Euler assumes that as for the solid friction, the fluid friction is proportional to the applied normal force. A detailed development of five different problems of discharge are presented in his treatise, taking into account the loss of head in the conduits. In the appendix, an example is given for the calculation of the jet heights of a particular fountain, fed with conduits of different amplitudes.