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How is nozzle efficiency calculated?

How is nozzle efficiency calculated?

The ratio of the nozzle total to static pressure ratio is called the nozzle pressure ratio (NPR). Considering the energy equation for the nozzle, the specific total enthalpy is equal to the static enthalpy plus the square of the exit velocity divided by two.

What do you mean by nozzle efficiency?

[′näz·əl i‚fish·ən·sē] (mechanical engineering) The efficiency with which a nozzle converts potential energy into kinetic energy, commonly expressed as the ratio of the actual change in kinetic energy to the ideal change at the given pressure ratio.

What is the typical efficiency of the nozzle?

Nozzle efficiencies are typically above 90 percent, and nozzle efficiencies above 95 percent are not uncommon.

How do you calculate isentropic efficiency of nozzle?

The isentropic efficiency of nozzles is defined as the ratio of the actual kinetic energy at exit to the kinetic energy at the exit when the process is isentropic for the same inlet and exit pressures.

Which factors affect the efficiency of nozzle?

Factors affecting nozzle efficiency

  • Material of the nozzle.
  • Size and shape of the nozzle.
  • Finish of the nozzle.
  • Angle of divergence.
  • Nature of the fluid and its state,
  • Friction.
  • Fluid velocity.
  • Turbulence in the flow passages.

What is critical pressure ratio of steam nozzle?

The ratio of the pressure at the section where sonic velocity is attained to the inlet pressure of a nozzle is called the critical pressure ratio. It happens at Mach number equals 1.

How is isentropic efficiency calculated?

The isentropic efficiency is defined as the ratio of the actual work to the ideal work obtained by an isentropic expansion:(11.13)η=i5−i6i5−i6∗,where i5 is the specific enthalpy at the beginning of the expansion, i6 is the enthalpy at the end of the expansion for the actual turbine, and i6∗ is the enthalpy at the end …

What is isentropic efficiency of nozzle?

What is nozzle in mechanical engineering?

nozzle in Mechanical Engineering A nozzle is a narrow pipe, used to control the flow of a fluid as it leaves another pipe. Water is sprayed from nozzles above the condenser. The liquid can be sprayed into a gas stream by means of a nozzle which disperses the liquid into a fine spray of drops.

What is the formula for stage efficiency?

The energy supplied per stage of an impulse turbine is equal to kinetic energy given by ηb=ṁC2i2 and assuming that the kinetic energy leaving the stage is wasted. Blade efficiency will be maximum when C0 (Absolute velocity of steam at exit to moving blades) is minimum, that is, when β=90o, or the discharge is axial.