Derivation of Bernoulli's Principle

In summary, there are multiple ways to derive Bernoulli's principle for incompressible fluids with gravity. The Euler equation is one method used in Fluid Mechanics textbooks, while other textbooks may use energy conservation. The Euler method may be more difficult for some individuals. However, both methods ultimately lead to the same result, as Bernoulli's principle is a special case of the Navier-Stokes equations. These equations are based on Conservation of Mass, Momentum, and Energy, and the Euler equation is derived from the conservation of energy. The use of the Euler method may be helpful in studying various parameters such as pressure, time, velocity, flow rate, and power. It would be beneficial to compare and understand the two different approaches in order
  • #1
MaxManus
277
1
In my Fluid Mechanics textbook they use the Euler equation to derive Bernoulli's principle for incompressible fluids with gravity. In my earlier introduction to mechanics textbook they used energy conservation. Is there a reason for using the Euler equation or is it just to show more ways to derive Bernoulli's principle.
The reason I ask is because I find the Euler method more difficult.

I use Kundu/Cohen Fluid Mechanics
 
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  • #2
well the origin in fluid mechanics theoris is NAVIER STOKES EQUATIONS as they cover all the conditions of the fluid as ( steady or unsteady ) comprissible or not , newtenion or not and bernollis equation is a special case of the navier stokes and so is eulers you can study this equation it will enable you to study many parameters pressure , time , velocity k, flow rate even power also
 
  • #3
As maxx mentioned Bernoulli's is derived from the full Navier-Stokes equations. Taking the full set of equations and ignoring viscosity you get the Euler equations.

Recall that these governing equations are based on Conservation of Mass, Momentum, and Energy. Those form a set of 5 coupled equations.

Bernoulli's is a special case basically of the energy equation. So, it is derived from Euler equation which is derived from conservation of energy.

edit: Perhaps you can show us the two different approaches. We might be able to help a little more knowing what you're looking at.
 
  • #4
Thanks, then I will sit down and try to learn the cross-product rules.

Minger: the problem is my math knowledge.
 

1. What is Bernoulli's Principle?

Bernoulli's Principle is a fundamental law of fluid dynamics that describes the relationship between the speed of a fluid and its pressure. It states that as the speed of a fluid increases, its pressure decreases.

2. Who discovered Bernoulli's Principle?

Daniel Bernoulli, a Swiss mathematician and physicist, first described Bernoulli's Principle in his book "Hydrodynamica" in 1738.

3. What is the equation for Bernoulli's Principle?

The equation for Bernoulli's Principle is P1 + 1/2ρv1^2 + ρgh1 = P2 + 1/2ρv2^2 + ρgh2, where P is pressure, ρ is density, v is velocity, g is acceleration due to gravity, and h is height.

4. What are some real-life applications of Bernoulli's Principle?

Bernoulli's Principle is used in many engineering and physics applications, including airplanes, car aerodynamics, and air conditioning systems. It also explains the lift force that allows birds and airplanes to fly.

5. How is Bernoulli's Principle derived?

Bernoulli's Principle can be derived using the law of conservation of energy and the continuity equation, which states that the mass flow rate of a fluid is constant. By equating the energy at two different points in a fluid, the equation for Bernoulli's Principle can be obtained.

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