## What is the relationship between pressure drop and velocity?

When you increase the velocity of fluid, the collision between molecules increases resulting into greater loss of kinetic energy, in turn, greater pressure drop.

**Why pressure decreases with increase in velocity?**

If the flow encounters a constriction, the velocity must increase due to mass conservation. That increased velocity means the flow has more kinetic energy. That energy had to come from somewhere, so the pressure has to drop to match that energy change. Pressure is defined as force per unit area..

**Does drop in pressure increase flow rate?**

More pressure changes the velocity of the fluid, but it also decreases the flow or output.

### What happens to pressure when velocity increases?

Bernoulli’s principle states that as velocity increase pressure decreases. But higher the velocity, greater is the temperature and pressure must be high.

**What happens if pressure drop is too high?**

Excessive pressure drop will result in poor system performance and excessive energy consumption. Flow restrictions of any type in a system require higher operating pressures than are needed, resulting in higher energy consumption.

**Does higher velocity mean lower pressure?**

The higher the velocity of a fluid (liquid or gas), the lower the pressure it exerts. This is called Bernoulli’s Principle. Fluid pressure is caused by the random motion of the fluid molecules.

#### Who explained the relation between pressure and velocity?

In simple words, Bernoulli’s formula explains the relation of pressure and velocity is inversely proportional. It means that when pressure increases, the velocity decreases, keeping the algebraic sum of potential energy, kinetic energy, and pressure constant.

**What happens to velocity and pressure inside the constriction?**

In a constriction, area goes down, and as flow-rate = velocity * area = constant, as area decreases, velocity increases. As density and gravity and height are assumed to be constant, Pressure must decrease in this constriction.

**Does lower pressure mean higher velocity?**

What is the relationship between pressure and velocity for a liquid and gas? A: The higher the velocity of a fluid (liquid or gas), the lower the pressure it exerts. This is called Bernoulli’s Principle.

## Is pressure inversely proportional to flow?

Cross-section of the fluid’s body through which a fluid is flowing is inversely proportional to the velocity and pressure.

**What is the pressure drop for a straight section of ductwork?**

Again looking at duct sizing diagrams (in Guide C or elsewhere) this gives a pressure drop of 0.21Pa/m duct. So the pressure drop for this straight section is 10 x 0.21 = 2.10Pa. The following bend is treated in just the same way as with any other duct fitting.

**Is low velocity a problem in air ducts?**

Faster air means more turbulence, more resistance, and more noise. But I run into a lot of people who think that low velocity also can be a problem in ducts.

### What is the pressure drop in velocity during the expansion process?

So the pressure loss is 0.20 x 21.60 = 4.32Pa. However, an interesting change takes place at the same time. As the air passes through the expansion, the velocity will drop to 0.6/0.2 = 3.00m/s giving p v = 0.6×3.002 =5.40Pa. Hence the velocity pressure has dropped by 21.60-5.40 = 16.20Pa.

**What is the velocity of air entering the air ducts?**

As the air enters the ductwork system – in Figure 3 through a simple louvred entry – the air will be accelerated from the still air outside the louvre to a velocity determined by the volume flowrate, q v (m 3 /s) of the air, and the area, A (m 2) of the duct. In this case as c = q v /A = 0.6/0.1 = 6m/s.