Steam flows steadily through an adiabatic turbine. the inlet conditions of the steam are 4 mpa, 500°c, and 80 m/s, and the exit conditions are 30 kpa, 92 percent quality, and 50 m/s. the mass flow rate of the steam is 12 kg/s. determine (a) the change in kinetic energy, (b) the power output, and (c) the turbine inlet area.

a)23.4KW

b)12.11MW

c)1.155m^2

Explanation:

Hello!

To solve this problem follow the steps below

1. We will call 1 at the turbine entrance and 2 at the exit.

2. To calculate the change in kinetic energy, calculate the kinetic energy at the entrance and exit of the turbine and find the difference.

E=0.5mV^2

m=mass flow=12kg/s

E=kinetic energy

V=speed

solving

3. We find the enthalpies in states 1 and 2, and the density in the state 2 by thermodynamic tables

note: Through laboratory tests, thermodynamic tables were developed, these allow to know all the thermodynamic properties of a substance (entropy, enthalpy, pressure, specific volume, internal energy etc ..)  

through prior knowledge of two other properties such as pressure and temperature.  

h1=Enthalpy(Water;T=500C;P=4000kPa)

=3445KJ/kg

h2=Enthalpy(Water;x=0,92(quality);P=30kPa)=2438KJ/kg

density2=0.2078kg/m^3

4.

use the first law of thermodynamics that states that the energy entering the system is the same as the one that must go out, consider the flow energy, the work done and the kinetic energy

5.

to find the speed at the exit of the turbine we remember that the mass flow is defined as the product between the velocity density and the cross-sectional area

m=(density)(A2)V2

electromagnetic shielding is the practice of reducing the electromagnetic field in a space by blocking the field with barriers made of conductive or magnetic materials. shielding is typically applied to enclosures to isolate electrical devices from their surroundings, and to cables to isolate wires from the environment through which the cable runs. electromagnetic shielding that blocks radio frequency electromagnetic radiation is also known as rf shielding.

the shielding can reduce the coupling of radio waves, electromagnetic fields and electrostatic fields. a conductive enclosure used to block electrostatic fields is also known as a faraday cage. the amount of reduction depends very much upon the material used, its thickness, the size of the shielded volume and the frequency of the fields of interest and the size, shape and orientation of apertures in a shield to an incident electromagnetic

from wikipedia

find the surface area of the sphere to the nearest square unit. use a calculator.

a. 254 in.2

b. 64 in.2

c. 127 in.2

d. 1,018 in.2