Question

Kinetic energy correction factor for laminar flow between parallel plates?

Answer 1

Hint: A kinetic energy term with a velocity square factor appears in the energy equation for ideal flow. Ideal flows are viscid in our opinion. Shear effects are absent in viscid flow, since the flow is uniform around the cross section of the flow. It denotes that the velocity is constant or uniform around the flow's cross section. As a result, the velocity at every point on the segment equals the average velocity. For the ideal flow, the total kinetic energy at the section can be calculated using the average velocity.

Complete step-by-step solution:
Since average velocity is simple to find, we tend to use it to measure kinetic energy. The rate of flow divided by the area of flow equals average velocity at any cross section of flow.
Let’s see how we can find the correction factor. To calculate the correction factor, we must first calculate the total kinetic energy across the flow cross section in real flow. The real total kinetic energy is then compared to the total kinetic energy calculated using the average velocity. By multiplying the correction factor on the average velocity side, both terms can be equated. As a result, the correction factor is proportional to the difference between the real total kinetic energy and the kinetic energy calculated using average velocity.
Kinetic energy correction factor value for a fully formed laminar pipe flow is around\[2\], whereas it is between \[1.04\] and \[1.11\] for a turbulent pipe flow. For a turbulent flow, it is common to use the number\[1\] .

 Note:In simple words we can say that the ratio of the kinetic energy of flow per second based on real velocity across a section to the kinetic energy of flow per second based on average velocity across the same section is known as the kinetic energy correction factor.