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What is Fluid and the types of Fluids ? 

        Today We discuss fluid and different types of fluids. We discuss these types of fluid in this article and with these types, we also discuss different properties of fluids.

 Fluid:

         First of all, I tell you anything that has mass and the substances that occupy masses called Matter.

Matter can be divided into three types excluding type which is plasma.

Solid

Liquid

Gasses

The combination of liquid and gasses are called Fluid. Anything that can flow is called Fluid. Liquid and Gasses are flow so these are fluid-solid cannot flow so it is not included in the fluid.

Classification Of Types of Fluid:

There are different types of fluid.

One Dimensional Flow:

         The flow describes the function of velocity in time and only in one space coordinate(x).

For example:

        Flow-through a pipe is a one-dimensional flow.

  Two Dimensional Flow:

        The flow describes the function of velocity in time and in two space coordinates(x,y).

For example:

       The viscous flow between parallel plates, flow over a long spillway, etc.

Three Dimensional Flow:

    The flow is in converging, diverging, and in an open channel are known as three-dimensional flow. In which three space coordinates (x,y,z) are known.

For example: 

   The flow in a river, or at the inlet of the nozzle is a three-dimensional flow.

Laminar Flow:

 The flow in which all particles proceed along a smooth parallel path and all particles on any path will follow it without deviation. This flow occurs in parallel layers without mixing the layers. The flow in which all particles move in straightway does not deviate. The flow in which adjacent layers do not cross to each other and move along a well-defined way.

For example:

  The flow of blood in small veins, flow of oil in bearings, etc.

Turbulent Flow:

    The flow moves in an irregular way, not in a straight line. The flow moves in an irregular manner in the flow field. Each particle has superimposed on its mean velocity fluctuating velocity components both transverse to or in the direction of net flow. In turbulent flow occur when liquid moving faster mixing the parallel layers.

For example:

     Flow through a river or canal, smoke from cigarettes, etc.

Transitional Flow:

 Transitional flow is the mixture of laminar and turbulent flow. Each flow behaves in different manners in terms of its energy frictional loss.

Reynolds number less than 2000 flow is called Laminar.

Reynolds number more than 4000 flow is called turbulent.

Reynolds number is between 2000 and 4000 is called transitional.

Critical Velocity:

The velocity below which flow remains streamline is called laminar flow and if the velocity of the fluid is more than this velocity then the fluid is turbulent.

Pressure Flow:

It is also called pipe flow. The flow may occur from lower to higher points and vice versa.

For example:

 Flow in a piping system is an example of pressure flow.

Gravity Flow:

It is also called open channel flow. The flow may occur from higher to lower points.

For example:

    Flow in an open channel like rivers, canals, etc.

Real Fluid:

It is also called viscid flow. Real fluid is the fluid in which viscosity is not zero. It is found in practical life. It occurs in reality.

For example:

   Water, Air, etc.

Ideal Fluid:

 It is also called inviscid flow. Ideal fluid is the fluid in which viscosity is zero. It is not found in reality. It is imaginary fluid.

Newtonian Fluid:

A fluid that obeys the newton law of viscosity. A fluid in which shear stress is directly proportional to the velocity gradient is called Newtonian fluid.

For example:

 Water, Benzene, etc.

Non-Newtonian Fluid:

A fluid that does not obey the newton law of viscosity. A fluid in which shear stress is not directly proportional to the velocity gradient is known as nonnewtonian fluid.

For example:

 Plaster, paster, etc.

Compressible fluid flow:

A compressible fluid is a fluid in which density does not remain constant. A fluid in which density varies.A fluid in which density changes with the change of an external force.

For example:

 Gas flow etc.

Incompressible Fluid:

An incompressible fluid is a fluid in which density remains constant. A fluid in which density does not change with the change of an external force.

For example:

     Liquid flow etc.

Steady Flow:

The flow in which characteristics of fluid-like velocity, pressure, density at any point do not change with respect to time is called steady flow.

           

For example:

  water flow with constant discharge in a pipe system etc.

Unsteady Flow:

 The flow in which characteristics of fluid-like velocity, pressure, density at any point change with respect to time is called unsteady flow.

         

For example:

    water flow with varying discharge in a pipe system etc.

Spatially Constant Fluid:

 The fluid is spatially constant if the local average velocity and fluid density are identical at any point in the flow field.

Spatially Variable Fluid:

  The fluid is spatially variable if the local average velocity and fluid density are not identical (varies) at any point in the flow field.

Uniform Fluid:

 The fluid in which the velocity at a given time does not change with respect to space is called uniform fluid flow. If the flow section(shape and area) remains uniform velocity also remains uniform.

For example:

Flow-through a long straight pipe of uniform diameter etc.

Non-Uniform Fluid:

 The fluid in which the velocity at given time changes with respect to space is called nonuniform fluid flow. If the flow section(shape and area)  does not remain uniform velocity is also nonuniform.

For example:

 Flow-through a long straight pipe of different diameters etc.

Established Flow:

   The region at when viscosity has played its important role velocity profile (advance front) does not change.

Unestablished Flow:

The length up to which velocity profile (advance front) changes.

Rotational Flow:

The flow in which fluid particles flowing in a streamline and rotate about their own axis is called rotational flow.

For example:

The flow of liquid in a rotating cylinder(forced vortex) etc.

Irrotational Fluid Flow:

The flow in which fluid particles flowing in a streamline and don't rotate about their own axis is called irrotational flow. It is also called irrigational fluid flow.

For example:

The flow of liquid in emptying vortex etc.

Subcritical Fluid Flow:

 It is the flow that behaves slow and stable way. It has a Froude number of less than one. Gravitational force acts on it. The flow in which channel depth is greater than critical channel depth. The velocity of fluid and slope of fluid is less than critical velocity and critical slope. The velocity of flow is less than the wave velocity.

Supercritical Fluid Flow:

It is the flow that behaves rapid, fast, and unstable way. It has a Froude number greater than one. Inertial forces act on it. The flow in which channel depth is less than critical channel depth. The velocity of fluid and slope of fluid is greater than critical velocity and critical slope. The velocity of flow is larger than the wave velocity.

Critical fluid flow:

It is the flow in which the Froude number is equal to one. Critical flow occurs when fluid velocity is equal to the wave velocity that is generated and distributed.