# Relationship between velocity and static pressure for fluid flow in convergent pipe

### Pressure - Velocity relation in fluids | CrazyEngineers

It is a known fact that as the velocity of a fluid increases the pressure decreases accordingly. TRUE for a flow through a Convergent or Divergent Nozzle attatched to a pipe, Also it is applicable to Static fluids and not flows. The pressure from the surrounding fluid will be causing a force that can do This inverse relationship between the pressure and speed at a point in a fluid is called Bernoulli's principle. . Consider the following diagram where water flows from left to right in a pipe that Turbulence at high velocities and Reynold's number. The pressure drops in a convergent nozzle because of the Bernoulli Principle. of a hose or pipe used to control the movement of a fluid like water or air. motion is converted into faster forward motion, known as stream flow.

No, dont confuse in it, Pressure is a different entity and Velocity of flow is a different entity in any fluid flow. The fluid is translating, so the fluid "bends" not the normal force. A molecule in contact with a wall will reflect or bounce inwards, as it translates in a general direction along the flow assuming the walls are smooth.

### fluid dynamics - Relation between pressure, velocity and area - Physics Stack Exchange

The fluid molecule does not bend or reflect inwards. It is not this way that the flow progresses.

It is the driving force column pressure or some other external power sorce like a pump or piston pushing or fluid already having some motion that causes the flow. The driving force ives the molecules the energy to overcome the shear force between the surface material and themselves and continue to flow.

## What is Bernoulli's equation?

The flow is always in a straight line in case of a laminar flow. For analogy, you can consider the example of a projectile which when fired in a straight horizontal direction with sufficient velocity, maintains its straight path until it has enough energy left to overcome the gravitational force acting downwards. It will bend down or change direction only after the gravity becomes dominant on the velocity in horizontal direction.

The same happens with the fluid particles in a flow, they are continously pwered by the driving force from behind, ehich keeps them in straight motion. And I will like to read the reasearch paper you mentioned regarding the Gauss and Faradays equations. Would you mind mailing them to me, ofcourse if you dont have a problem in sharing it.

### What is Bernoulli's equation? (article) | Khan Academy

I will be thankful if you can email them to me. Felix Hagan Module code: In a fluid system, such as airflow and current, with the increase in flow velocity,the pressure which produced by fluid will decrease. Daniel Bernoulli discovered this principle in Inversely, with the decrease of flow velocity, the static pressure of fluid will increase.

However,the total magnitude of static pressure and kinetic pressure of fluid is constant. This equation can also shown as: So only ideal fluid is available,which viscosity can be ignored and can not be compressed. The three different kinds of forms are potential energy,pressure energy and kinetic energy.

And these three different kinds of form can be converted to each other. In the ideal situation,which without flow energy loss. The total energy of these three different kinds of form is constant.

During this experiment,only water passes through the tube. Based on the conservation of mass,the total rate of fluid is constant.

So the formula is shown below: The Bernoulli equation states that, where points 1 and 2 lie on a streamline, the fluid has constant density, the flow is steady, and there is no friction. Although these restrictions sound severe, the Bernoulli equation is very useful, partly because it is very simple to use and partly because it can give great insight into the balance between pressure, velocity and elevation. How useful is Bernoulli's equation? How restrictive are the assumptions governing its use?

Here we give some examples. The flow therefore satisfies all the restrictions governing the use of Bernoulli's equation. Upstream and downstream of the contraction we make the one-dimensional assumption that the velocity is constant over the inlet and outlet areas and parallel.

One-dimensional duct showing control volume.

When streamlines are parallel the pressure is constant across them, except for hydrostatic head differences if the pressure was higher in the middle of the duct, for example, we would expect the streamlines to diverge, and vice versa.

If we ignore gravity, then the pressures over the inlet and outlet areas are constant. Along a streamline on the centerline, the Bernoulli equation and the one-dimensional continuity equation give, respectively, These two observations provide an intuitive guide for analyzing fluid flows, even when the flow is not one-dimensional. For example, when fluid passes over a solid body, the streamlines get closer together, the flow velocity increases, and the pressure decreases.

Airfoils are designed so that the flow over the top surface is faster than over the bottom surface, and therefore the average pressure over the top surface is less than the average pressure over the bottom surface, and a resultant force due to this pressure difference is produced.

This is the source of lift on an airfoil. Lift is defined as the force acting on an airfoil due to its motion, in a direction normal to the direction of motion. Likewise, drag on an airfoil is defined as the force acting on an airfoil due to its motion, along the direction of motion.