A pump transfers mechanical energy to a fluid by raising its pressure. The pressure of a flowing fluid is associated with its mechanical energy.
Pa=N/m2=N.m/m3=J/m3 Energy per unit volume and P/ρ has unit J/Kg which is energy per unit mass.
The book I am studying from (Thermodynamics: An engineering approach) states that pressure is not energy but a force acting on a fluid through a distance to produce work. Flow work can be viewed as part of the energy of a flowing fluid.
If we consider the system as the fluid element shown, the fluid element has stored forms of energy which are the kinetic and potential energies as well as the microscopic forms of energy (internal energy). Since transporting a fluid from one to another does not involve the conversion of thermal, chemical, or nuclear forms of energy into mechanical energy, the only forms of energy contained within the system would be kinetic and potential energy.
Shouldn't the net force acting on the fluid element by the surrounding fluid, as it is pushed through a distance dx, be equal to the changes in the kinetic and potential energies of the fluid element. Why is flow work, which is a dynamic form of energy, not contained within the system but is realized at the system boundary, where it is transferred to the the system from the surrounding forces and manifests itself as an increase or decrease in kinetic a part of the flowing fluid ?
Pa=N/m2=N.m/m3=J/m3 Energy per unit volume and P/ρ has unit J/Kg which is energy per unit mass.
The book I am studying from (Thermodynamics: An engineering approach) states that pressure is not energy but a force acting on a fluid through a distance to produce work. Flow work can be viewed as part of the energy of a flowing fluid.
If we consider the system as the fluid element shown, the fluid element has stored forms of energy which are the kinetic and potential energies as well as the microscopic forms of energy (internal energy). Since transporting a fluid from one to another does not involve the conversion of thermal, chemical, or nuclear forms of energy into mechanical energy, the only forms of energy contained within the system would be kinetic and potential energy.
Shouldn't the net force acting on the fluid element by the surrounding fluid, as it is pushed through a distance dx, be equal to the changes in the kinetic and potential energies of the fluid element. Why is flow work, which is a dynamic form of energy, not contained within the system but is realized at the system boundary, where it is transferred to the the system from the surrounding forces and manifests itself as an increase or decrease in kinetic a part of the flowing fluid ?
