Table of Contents

## What do the Navier-Stokes equation represent?

The Navier-Stokes equations represent the conservation of momentum, while the continuity equation represents the conservation of mass.

## What is a Stokesian fluid?

Stokes flow (named after George Gabriel Stokes), also named creeping flow or creeping motion, is a type of fluid flow where advective inertial forces are small compared with viscous forces.

**What is the velocity profile for Poiseuille flow?**

When the flow is fully developed and laminar, the velocity profile is parabolic. Within the inlet length, the velocity profile changes in the direction of the flow and the fluid accelerates or decelerates as it flows. There is a balance among pressure, viscous, and inertia (acceleration) forces.

### What is Dilatational viscosity?

Volume viscosity (also called bulk viscosity, or dilatational viscosity) is a material property relevant for characterizing fluid flow. Common symbols are or. . It has dimensions (mass / (length × time)), and the corresponding SI unit is the pascal-second (Pa·s).

### What is a kinematic viscosity?

The kinematic viscosity is an atmospheric variable defined as the ratio between the dynamic viscosity μ and the density ρ of the fluid, i.e. (7.25) and depends on both air temperature and pressure. For air at sea level pressure and 20 °C, ρ = 1.205 × 10−3 g cm−3 and ν = 0.15 cm2 s−1.

**Is MU dynamic or kinematic viscosity?**

Equation (1) is known as the Newtons Law of Friction. Water at 20.2oC (68.4oF) has the absolute viscosity of one – 1 – centiPoise….Dynamic (absolute) Viscosity.

Liquid | Absolute Viscosity *) (N s/m2, Pa s) |
---|---|

Water | 10-3 |

Olive Oil | 10-1 |

Glycerol | 100 |

Liquid Honey | 101 |

## How does viscosity affect laminar flow?

(a) Laminar flow occurs in layers without mixing. Notice that viscosity causes drag between layers as well as with the fixed surface. (b) An obstruction in the vessel produces turbulence. Turbulent flow mixes the fluid.

## How do you calculate dynamic viscosity of water?

The dynamic viscosity of water is 8.90 × 10−4 Pa·s or 8.90 × 10−3 dyn·s/cm2 or 0.890 cP at about 25 °C. Water has a viscosity of 0.0091 poise at 25 °C, or 1 centipoise at 20 °C. where A=2.414 × 10−5 Pa·s ; B = 247.8 K ; and C = 140 K….Water – Density Viscosity Specific Weight.

Temperature [°C] | Viscosity [mPa·s] |
---|---|

100 | 0.2822 |

**What is the formula for kinematics viscosity?**

Kinematic Viscosity (cSt) = (0.22 × t) − (195/t).

### What is kinematic viscosity equation?

The units of kinematic viscosity are established on time and area. It is the ratio of the dynamic viscosity to its density, a force independent quantity. It is the ratio of the area of time; henceforth it is m22/s or ft22/s. The kinematic viscosity formula is expressed as, ν = μ/ρ

### Why is it difficult to obtain the analytical solution of Navier Stokes NS equations choose the correct reasoning’s from the given options?

There are no methods so far or very highly complex methods to solve these non linearity. N-S equations also show such kind of non linearity hence Analytical solution does not exists. Non-linear problems even ordinary differential equation are difficult if not impossible to solve analytically.

**What is difference between kinematic viscosity and dynamic viscosity?**

Dynamic viscosity is expressed as the ratio of shear stress to shear strain. The unit of measurement is Pa s. Usually, it is measured in centipoise (cP). Kinematic viscosity is expressed as the ratio of fluid dynamic viscosity to its density.