The full name of N-S equation is "Naville-Stokes equation". The original form was put forward by Naville in 1827. After development, the final form was put forward by Stokes in 1845. In the play, Grandma Evelyn took Mary to the Massachusetts Institute of Technology with visiting rights, and asked the professor to give Mary a test. She wanted to personally confirm whether Mary was really a mathematical genius, so she came up with this problem, and finally Mary solved it.

The influence and significance of N-S equation;

N-S equation reflects the basic mechanical law of viscous fluid (also known as real fluid) flow, which is of great significance in fluid mechanics.

It is a nonlinear partial differential equation, which is very difficult and complicated to solve. Until the solution idea or technology is further developed and broken through, its exact solution can only be obtained on some very simple special flow problems. But in some cases, the equation can be simplified and an approximate solution can be obtained.

For example, at Reynolds number, the viscous force is much smaller than the inertial force outside the boundary layer of the flowing object, and the viscous term in the equation can be ignored, simplifying the N-S equation into the Euler equation in ideal flow; In the boundary layer, the N-S equation can be simplified to the boundary layer equation, and so on. Since the appearance and rapid development of computers, great progress has been made in the numerical solution of N-S equations.