In the context of the General Energy Equation, Flow Energy is defined as FE = PV. What do P and V represent?

In the context of the General Energy Equation, Flow Energy is defined as FE = PV. What do P and V represent?

• A. Pressure and Volume
• B. Power and Velocity
• C. Potential and Velocity
• D. Pressure and Velocity

Answer: (A)

Flow energy in the General Energy Equation is the work needed to push fluid into or out of a control volume, so it is represented by the product P times V. Here, P is the fluid pressure (force per unit area) and V is the volume of fluid involved. The combination P·V has the correct units for energy (Pa·m^3 = N·m = Joule), which makes it the energy term associated with flow work. This is distinct from power (which is energy per unit time) and from velocity (which relates to kinetic energy), and it’s different from gravitational potential energy. So the quantities are pressure and volume.

Flow energy in the General Energy Equation is the work needed to push fluid into or out of a control volume, so it is represented by the product P times V. Here, P is the fluid pressure (force per unit area) and V is the volume of fluid involved. The combination P·V has the correct units for energy (Pa·m^3 = N·m = Joule), which makes it the energy term associated with flow work. This is distinct from power (which is energy per unit time) and from velocity (which relates to kinetic energy), and it’s different from gravitational potential energy. So the quantities are pressure and volume.