Dynamic Pressure: Is 9,81 kPa Lost per Vertical Meter?

In summary, for every vertical meter of piping in a house with water flowing through, there is a loss of 9.81 kPa of dynamic pressure. This is due to the weight of the water and the acceleration due to gravity. For water, this equates to a pressure contribution of 9.81 kPa per meter of height.
  • #1
TSN79
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A house has x meters of vertical piping with water flowing through. I'm just wondering if it is correct that one for every vertical meter of pipe loses 9,81 kPa of dynamic pressure?
 
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  • #2
TSN79 said:
A house has x meters of vertical piping with water flowing through. I'm just wondering if it is correct that one for every vertical meter of pipe loses 9,81 kPa of dynamic pressure?
Correct. Dynamic or static pressure.

[tex]P = F/A = mg/A = \rho V g/A = \rho Ahg/A = \rho hg[/tex]

where h is the height and g is the acceleration due to gravity.

Since for water [itex]\rho = 1 \text{g/cm}^3 = 1000 \text{kg/m}^3[/itex], the pressure contributed by one metre high of water is 9.81*1000 Pa = 9.81KPa.

AM
 
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  • #3


I can confirm that the statement is correct. Dynamic pressure is defined as the pressure due to the motion of a fluid, and it decreases with an increase in height. This is due to the effect of gravity on the moving fluid, which causes a loss of kinetic energy and a decrease in pressure. Therefore, for every vertical meter of piping, there will be a loss of 9.81 kPa of dynamic pressure.

In the case of a house with x meters of vertical piping, the total loss of dynamic pressure can be calculated by multiplying 9.81 kPa by the number of meters of piping. This can be important to consider in the design and maintenance of piping systems, as it can impact the flow rate and pressure of the fluid being transported.

Additionally, other factors such as the diameter and material of the piping can also affect the loss of dynamic pressure. It is important to take these factors into account when designing a piping system to ensure efficient and effective fluid flow.

In conclusion, the loss of 9.81 kPa of dynamic pressure per vertical meter is a scientifically accurate statement and should be considered in the design and maintenance of piping systems.
 

1. What is dynamic pressure?

Dynamic pressure is a measure of the force exerted by a fluid in motion. It is caused by the movement of the fluid and is calculated by multiplying the density of the fluid by the square of its velocity.

2. How is dynamic pressure related to air resistance?

Dynamic pressure is one of the components of air resistance, also known as drag. As an object moves through a fluid, such as air, it experiences a force due to the fluid's resistance. This force is made up of two parts: static pressure and dynamic pressure. Dynamic pressure is the part of the force caused by the movement of the fluid.

3. Why is 9,81 kPa lost per vertical meter?

This is due to the decrease in air density as altitude increases. As you move higher in the atmosphere, the air becomes less dense, meaning there are fewer air molecules per unit volume. This decrease in density results in a decrease in dynamic pressure, which is measured in units of kilopascals (kPa).

4. What is the significance of 9,81 kPa?

9,81 kPa is approximately equal to 1 atmosphere of pressure at sea level. This means that the dynamic pressure at sea level is equivalent to the pressure exerted by the entire weight of the Earth's atmosphere. As altitude increases, the dynamic pressure decreases due to the decrease in air density.

5. How is dynamic pressure used in engineering and aerodynamics?

Dynamic pressure is an important factor in designing and analyzing objects that move through fluids, such as airplanes or cars. It helps engineers understand the forces acting on the object and how to optimize its design for maximum efficiency. In aerodynamics, dynamic pressure is often used in equations to calculate lift and drag forces on an aircraft.

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