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Godwin Kessy
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Can anyone please help me on the term pressure energy what does it really mean and If possible the calculations involved with it!
DaleSpam said:Pressure times volume is energy. So if that product changes then the energy has changed.
thrillhouse86 said:Strictly speaking isn't change in volume times a constant pressure energy ?
so if you had a situation where your volume stayed constant but your volume changed you would have a change in enthalpy ? i.e
dU = TdS - PdV
dH = TdS + VdP
It is any volume that you are interested in and the pressure within that volume. For instance, if you are interested in the work done by a piston as it expands then you would take the pressure inside the piston times the volume of the piston at the beginning of the power stroke and at the end of the power stroke. The difference is the work done by the piston during the expansion.Godwin Kessy said:But what is really that volume and the pressure.
May you please elaborated it
You should be shocked, it is not true in general. For instance, in outer space g=0, so mgh = 0, but pressure times volume is still energy and pistons and compressors don't run without energy input! Also, consider on earth, you can heat a gas inside a closed container, this will increase P and therefore increase PV without changing mgh.Godwin Kessy said:I was shocked when it was written that;
Pressure energy=mgh
DaleSpam said:You should be shocked, it is not true in general.
you didn't get what Dale meant by "general". There are many different types of pressure energy including several others in bernoulli's equation. Pressure due to gravity is only one type.Godwin Kessy said:Seriously it is true am telling you! May be you should look it over and help me out!
Its under the derivation of Bernouli's theorem!
Not quite, it's an inverse relationship. Bernoulli's equation multiplied by volume results in:Godwin Kessy said:Bernoulli ... Pressure energy=mgh
Pressure energy, also known as fluid energy or hydraulic energy, is the energy possessed by a fluid due to its pressure. It is a form of potential energy and is expressed in units of force per unit area (such as N/m2 or Pa).
Pressure energy is a fundamental concept in fluid mechanics, which is the study of fluids in motion and the forces and energy associated with them. The pressure energy of a fluid is an important factor in determining the flow behavior and characteristics of a fluid.
Pressure energy is used in a variety of applications, such as hydraulic systems in machines and vehicles, water distribution systems, and in the generation of electricity through hydropower. It is also important in the design of pumps, turbines, and other fluid-based machinery.
The pressure energy of a fluid can be calculated using the equation P = ρgh, where P is the pressure energy, ρ is the density of the fluid, g is the acceleration due to gravity, and h is the height of the fluid column. Alternatively, it can be calculated using the Bernoulli's equation, which takes into account the velocity and height of the fluid.
The pressure energy of a fluid is directly related to its pressure, so changes in pressure can affect the behavior of a fluid. For example, an increase in pressure can cause a fluid to flow faster, while a decrease in pressure can cause it to flow slower. Pressure energy also plays a role in the forces and work done by a fluid, as well as its potential for causing damage or performing useful work.