If the fluid is in free fall, the hagen poiseulle equation doesn't apply because there is no stationary solid pipe wall.ChaoY said:I honestly don't know what viscosity we should use yet. We're preparing a little experiment to show that Bernoulli equation can be used to calculate velocity for liquid with low viscosity. We also want to calculate the flow rate of the jet this time with viscous liquid. The idea is to show that the Bernoulli equation becomes less effective. Now we're wondering if we could use the Hagen-Poiseuille equation to do the job instead this time considering the viscosity. Do you know if this equation still works if the circular cross section varies from two points?
The Navier-Stokes equation is a fundamental equation in fluid mechanics that describes the motion of viscous fluids. It takes into account the effects of pressure, viscosity, and inertia on the velocity and pressure fields of a fluid.
The Navier-Stokes equation is important in many engineering and scientific applications, such as predicting the flow of air around an airplane wing or the flow of blood through blood vessels. It is also used in the study of weather patterns and ocean currents.
The Navier-Stokes equation assumes that the fluid is incompressible, the flow is steady and laminar, and the fluid has constant density and viscosity. It also assumes that the fluid is Newtonian, meaning that the viscosity is constant and does not depend on the shear rate.
The Hagen-Poiseuille equation is a simplified version of the Navier-Stokes equation that describes the flow of a viscous, incompressible fluid through a cylindrical pipe. It takes into account the effects of pressure and viscosity on the velocity and pressure fields of the fluid.
The Hagen-Poiseuille equation is commonly used in engineering applications, such as designing pipes and channels for fluid flow in plumbing, HVAC systems, and chemical processing. It is also used in medical applications, such as understanding blood flow through arteries and veins.