1, Euler equation, that is, differential equation of motion, belongs to the most important basic equation in inviscid fluid dynamics, and refers to the differential equation of motion obtained by applying Newton's second law to inviscid fluid micelles. Euler equation is widely used. 1755, the Swiss mathematician L. Euler first proposed this equation in his book General Principles of Fluid Motion.

2.N-S equation, namely Navier-Stokes equation, describes the motion equation of momentum conservation of viscous incompressible fluid. The equation of motion of viscous fluid was first proposed by Navier in 1827, which only considered the flow of incompressible fluid. Poisson put forward the motion equation of compressible fluid in 183 1. Saint-Venant independently put forward constant viscosity coefficient form and Stokes form in 1845 and 1845, both of which are called Naville-Stokes equations.