FLUID FLOW

Fluid flow analysis is an integral aspect of the reactor heat transfer process. The knowledge of local fluid properties, which are dependent on the flow distribution, is required for a complete analysis of heat transfer that could be accomplished by a computer. The pressure drop across a section of a reactor circuit has three components: frictional pressure drop, gravity pressure drop, and acceleration pressure drop. There are other potential sources of pressure loss in the core, in addition to frictional resistance associated with the surface of the fuel cans. The sources are the coolant channels’ inlet and outlet, gags, grids, or spacers that support the fuel cans, and any axial gaps between the cans.

THEORY

The motion of a fluid subjected to various unbalanced forces is known as fluid flow. It is primarily a branch of fluid mechanics, and fluid flow is concerned with the fluid’s dynamics. The fluid continues to move until other unbalanced forces are added to it.

For example, if you pour water from a bottle into a cup, the flow or velocity of the water is very high over the mug’s rim and very low towards the bottom half. Gravity is the imbalanced force here, and the water flow continues until the mug is tilted and the water is available in the mug.

Fluids of Different Types

Real fluid, Newtonian fluid, non-Newtonian fluid, ideal plastic fluid, incompressible fluid, and compressible fluid are examples of distinct forms of fluid.

Viscosity is a property of real fluids. The Newton law of viscosity is obeyed by Newtonian fluids, while the non-Newtonian law is not obeyed by Newtonian fluids. The shear stress in an ideal plastic fluid is proportional to the velocity gradient, and it is also greater than the yield value. When any external force is applied to an incompressible fluid, the density of the fluid does not change. An ideal fluid has no viscosity and has a constant density. The compressible fluid has the Mach number M>0.3, while the incompressible force has M< 0.3 

The Different Types of Fluid Flow

Fluid flow can be regular, irregular, viscous, or non-viscous. The velocity of the fluid is constant in steady fluid flow at any point along the path. However, in the case of unstable fluid flow, the fluid velocity varies between any two places. The viscosity of a fluid is measured by its thickness, and there are numerous viscous fluids available, such as oil, shampoo, and so on. In the case of uniform flow, the velocity of a flow between any two points should be the same in magnitude and direction at any given time. However, when the velocity of a non-uniform flow varies from point to point at any given period.

Laminar and Turbulent Flow

Laminar flow, also known as streamline flow, occurs when fluid flows in parallel layers with no interruption between them. In the case of turbulent flow, unpredictable property changes such as fast pressure variation and flow velocity exist. In rotational flow, the fluid particles rotate around their own axis, whereas in irrotational flow, the particles do not rotate around their own axis.

Equation of Fluid Flow

The pace at which a huge fluid moves through a unit area is known as mass flow rate. To put it another way, it’s the movement of mass per unit of time. The following is the mass flow rate formula:

Mass flow rate = ρAV

We can see from the equation that the mass flow rate is affected by the fluid’s density, velocity, and cross-sectional area.

Flow: Stable or Unstable

Fluid flow can be steady or unstable depending on the fluid’s velocity:

In a steady fluid flow, the fluid velocity is constant at all times.

When a flow is unstable, the velocity of the fluid might differ dramatically between any two points.

Flow: Viscous or Non-viscous

Viscous and non-viscous liquid flow are the two forms of liquid flow.

Viscosity is a measurement of a fluid’s thickness, and viscous fluids, such as motor oil or shampoo, are highly gloppy.

The ideal liquid

When a fluid cannot be compressed and its viscosity does not fall into the category of an ideal fluid, it is considered to be ideal. It’s a made-up fluid that doesn’t exist in real life.

Exceptionally fluid

All fluids are real since they all have viscosity.

Fluid Newtonian

A Newtonian fluid is defined as one that obeys Newton’s law of viscosity.

Fluid that isn’t Newtonian

Non-Newtonian fluid is defined as a fluid that does not obey Newton’s law of viscosity.

Plastic fluid that is ideal

Ideal plastic fluid is defined as one in which the shear stress is proportional to the velocity gradient and the shear stress is greater than the yield value.

CONCLUSION

The motion of a fluid subjected to various unbalanced forces is known as fluid flow. It is primarily a branch of fluid mechanics. Different types of flow of fluids like, laminar and turbulent flow, viscous and non viscous flow, stable or unstable flow are discussed above.