Nozzle Energy Balance: Solving Question B

In summary, the conversation discusses a problem involving the calculation of h at the outlet in a thermodynamics question. The problem provides values for v1, v2, and h1, and asks for the h2 value. The person asking the question has attempted to solve the problem but is unsure of their answer. They mention that the correct answers are provided in blue and question the discrepancy between the kinetic energies at the inlet and outlet and its effect on the h value.
  • #1
Ry122
565
2
Im having difficulty with question b in this problem:
[PLAIN]http://img705.imageshack.us/img705/9484/therm.jpg

Heres my attempt:
m(v1^2)*1/2)+h1)=m(v2^2)*1/2)+h2) + Qout
(v1^2)*1/2)+h1)=(v2^2)*1/2)+h2) + Qout
where v1 = 200ms^1
and v2 = 40ms^-1
and h1 = 3104.9kj/kg
And my answer is 22,000kj/kg for h2.
Can anyone see where I'm going wrong?

The blue writing on the question paper are the correct answers.
 
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  • #2
does anyone know how h = 3128kj/kg
the kinetic energy at the inlet is 20,000kj/kg
while at the outlet it's only 800.
How then could it be that h at the outlet is so low?
Isn't h at the exit dependent on the difference of these kinetic energies?
 

1. What is nozzle energy balance?

Nozzle energy balance is a calculation used in fluid mechanics to determine the energy changes that occur in a nozzle as a fluid flows through it.

2. Why is nozzle energy balance important?

Nozzle energy balance is important because it helps engineers and scientists understand the performance of a nozzle and its efficiency in converting fluid energy into kinetic energy.

3. How is nozzle energy balance calculated?

Nozzle energy balance is calculated by considering the energy conservation principle, where the total energy at the inlet of the nozzle is equal to the total energy at the outlet of the nozzle.

4. What are the key components of nozzle energy balance?

The key components of nozzle energy balance include the inlet and outlet pressures, inlet and outlet velocities, and the properties of the fluid, such as density and temperature.

5. How is nozzle energy balance used in real-world applications?

Nozzle energy balance is used in a variety of real-world applications, such as in the design of jet engines, rockets, and fuel injectors for internal combustion engines. It is also used in the analysis of fluid flow through pipes and channels in industrial processes.

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