#### Stokes equation

## What is Navier Stokes equation?

The Navier–Stokes equations are nonlinear partial differential equations describing the motion of fluids. A detailed discussion of fundamental physics—the conservation of mass and Newton’s second law—may, however, increase the understanding of the behaviour of fluids.

## Is the Navier Stokes equation solved?

In particular, solutions of the Navier–Stokes equations often include turbulence, which remains one of the greatest unsolved problems in physics, despite its immense importance in science and engineering. Even more basic properties of the solutions to Navier–Stokes have never been proven.

## What is Navier Stokes used for?

The Navier–Stokes equations are useful because they describe the physics of many phenomena of scientific and engineering interest. They may be used to model the weather, ocean currents, water flow in a pipe and air flow around a wing.

## What is Stoke’s law in physics?

noun Physics. the law that the force that retards a sphere moving through a viscous fluid is directly proportional to the velocity of the sphere, the radius of the sphere, and the viscosity of the fluid.

## How many Navier Stokes equations are there?

We only show five equations for six unknowns. An equation of state relates the pressure, temperature, and density of the gas. And we need to specify all of the terms of the stress tensor. In CFD the stress tensor terms are often approximated by a turbulence model.

## What is Stokes hypothesis?

The so-called Stokes’ hypothesis for a Newtonian fluid is reconsidered, and a possible explanation is given of the fact that, in spite of its evidently weak physical justification, it permits to obtain good results for the description of most compressible flows.

## What is the longest equation?

What is the longest equation in the world? According to Sciencealert, the longest math equation contains around 200 terabytes of text. Called the Boolean Pythagorean Triples problem, it was first proposed by California-based mathematician Ronald Graham, back in the 1980s.

## What are the 7 unsolved math problems?

Of the original seven Millennium Prize Problems set by the Clay Mathematics Institute in 2000, six have yet to be solved as of July, 2020:P versus NP.Hodge conjecture.Riemann hypothesis.Yang–Mills existence and mass gap.Navier–Stokes existence and smoothness.Birch and Swinnerton-Dyer conjecture.

## Who Solved the Navier Stokes problem?

mathematician Grigori Perelman

## What is equation of fluid motion?

The equation of motion is an expression of Newtons second law of motion: mass × acceleration = force. To apply this law we must focus our attention on a particular element of fluid, say the small rectangular element which at time t has vertex at P [= (x, y, z)] and edges of length δx, δy, δz.

## What is steady flow?

fluid mechanics In steady flow, the fluid is in motion but the streamlines are fixed. Where the streamlines crowd together, the fluid velocity is relatively high; where they open out, the fluid becomes relatively stagnant.

## What are energy equations?

Potential energy is dependent on the object’s mass, its height (h) and the acceleration due to gravity (g). Mathematically, this is E(p) = m•h•g.

## What is unit of viscosity?

Units for Dynamic Viscosity The most commonly used unit for dynamic viscosity is the CGS unit centipoise (cP), which is equivalent to 0.01 Poise (P). The SI unit for dynamic viscosity η is the Pascal-second (Pa-s), which corresponds to the force (N) per unit area (m^{2}) divided by the rate of shear (s^{–}^{1}).

## What is a Stokes?

A Stokes basket, also called a Stokes stretcher or Stokes litter, is a metal wire or plastic litter widely used in search and rescue. Originally designed by Charles Francis Stokes, these baskets have been notorious for spinning under the downdraft from the rotating helicopter blades.