Why there is no work transfer in nozzle?
A nozzle is a steady state steady flow device to create a high velocity fluid stream at the expense of its pressure. Usually, the process through the nozzle is treated as adiabatic. Since there are no moving parts, shaft work is zero. The potential energy term (for gases) is negligible and hence omitted.
Is there work done in a nozzle?
It is true to say that nozzles do no work in the same way its true normal forces do no work: their forces are always perpendicular to the direction of motion. It is wrong however to conclude that no work is done. It is true to say that the energy / volume doesn’t change on a streamline.
What is purpose of nozzle and diffuser?
Nozzles and Diffusers A nozzle is a device that increases the velocity of a fluid at the expense of pressure. A diffuser is a device that increases the pressure of a fluid by slowing it down. The cross sectional area of a nozzle decreases in the flow direction for subsonic flows and increase for supersonic flows.
Is diffuser a steady flow device?
Diffusers are considered steady-flow devices that increase the pressure of fluids by reducing their kinetic energy or in other words reducing the fluid moving velocity.
Is there work in a diffuser thermodynamics?
A nozzle is a device which accelerates fluid. During this process, velocity of fluid increases with decreasing pressure. A diffuser is a device which slows down fluid. The change of potential energy of fluid flowing into and out of nozzles and diffusers is negligible because of almost no height change.
Is nozzle a throttling device?
Thus nozzles are not isenthalpic but throttling valves are.
Is temperature constant in a diffuser?
The total temperature does not remain constant, it will only if the friction factor = 0, i.e. no losses.
What is the difference between a nozzle flow and a throttle device?
In both processes a flow moves from a higher to a lower pressure. In the nozzle the pressure drop generates kinetic energy, whereas that does not take place in the throttle process. The pressure drop in the throttle is due to a flow restriction and represents a loss.