QUESTION 3A high-pressure axial compressor for astagnation pressure ratio of 8.5. The mass flow rate of air through the compressor is 16 kg/sand the stagnation conditions at inlet are 200 kPa and 450 K. The polytropic efficiency is 91 %.jet engine rotates at 15,000 rpm with and overall(a) If the mean radius is 0.24 m and this is constant throughout the compressor, calculatethe total-to-total isentropic efficiency of the compressor and show that, for the stageloading to be less than 0.4 in all stages, eight stagesrequired.are(b) The compressor is designed with repeating stages and zero inlet swirl. If the inlet axialMach number is 0.52, calculate the mean flow coefficient and sketch the velocitytriangles for one stage. Show that the blade height at exit from the compressor is about7.8 mm.

Question
Asked Jul 17, 2019
334 views
QUESTION 3
A high-pressure axial compressor for a
stagnation pressure ratio of 8.5. The mass flow rate of air through the compressor is 16 kg/s
and the stagnation conditions at inlet are 200 kPa and 450 K. The polytropic efficiency is 91 %.
jet engine rotates at 15,000 rpm with and overall
(a) If the mean radius is 0.24 m and this is constant throughout the compressor, calculate
the total-to-total isentropic efficiency of the compressor and show that, for the stage
loading to be less than 0.4 in all stages, eight stages
required.
are
(b) The compressor is designed with repeating stages and zero inlet swirl. If the inlet axial
Mach number is 0.52, calculate the mean flow coefficient and sketch the velocity
triangles for one stage. Show that the blade height at exit from the compressor is about
7.8 mm.
help_outline

Image Transcriptionclose

QUESTION 3 A high-pressure axial compressor for a stagnation pressure ratio of 8.5. The mass flow rate of air through the compressor is 16 kg/s and the stagnation conditions at inlet are 200 kPa and 450 K. The polytropic efficiency is 91 %. jet engine rotates at 15,000 rpm with and overall (a) If the mean radius is 0.24 m and this is constant throughout the compressor, calculate the total-to-total isentropic efficiency of the compressor and show that, for the stage loading to be less than 0.4 in all stages, eight stages required. are (b) The compressor is designed with repeating stages and zero inlet swirl. If the inlet axial Mach number is 0.52, calculate the mean flow coefficient and sketch the velocity triangles for one stage. Show that the blade height at exit from the compressor is about 7.8 mm.

fullscreen
check_circle

Expert Answer

Step 1

Write the expression for stagnation pressure ratio.

 

help_outline

Image Transcriptionclose

Poe -8.5 Po1 Poe 8.5(20 kPa) Рое — 1700 kPa Obtain the total-to-total efficiency Poe 1 Po1 y-1 Рос . Pо (1.4-1 (8.5 14-1 1.4-1 (8.5)14x091 - 1 7=0.88x 100% 7t =88%

fullscreen
Step 2

Obtain the change in stagnation temperature.

 

help_outline

Image Transcriptionclose

Poe \m,) -1 01 ΔΤ n Po1 450(8.5Ix0 9T) -1 1.4-1 ΔΤ 8 AT = 53.887 K Obtain the angular velocity 2πΝ Ω- 60 27T(15000 rpm Ω : 60 1570.8 rad/s

fullscreen
Step 3

Obtain the blade veloci...

help_outline

Image Transcriptionclose

U n U (0.24 m) (1570.8 rad/s) U 376.99 m/s Obtain the load factor AT6CP (53.887 K)(1005 J/kg K) (376.99 m/s) y0.381 Thus, the stage load factor is 0.381, which is less than 0.4.

fullscreen

Want to see the full answer?

See Solution

Check out a sample Q&A here.

Want to see this answer and more?

Solutions are written by subject experts who are available 24/7. Questions are typically answered within 1 hour.*

See Solution
*Response times may vary by subject and question.
Tagged in

Engineering

Mechanical Engineering

Fluid Mechanics

Related Mechanical Engineering Q&A

Find answers to questions asked by student like you
Show more Q&A
add
question_answer

Q: Air enters the compressor of a gas-turbine plant at ambient conditions of 100 kPa and 30°C with a lo...

A: Given Information:For air compressor 

question_answer

Q: Required information     A two-stage compression refrigeration system operates with refrigerant-134a...

A: Show the T-s diagram for compression refrigeration cycle as in Figure (1). 

question_answer

Q: The mass fractions of a mixture of gases are 10 percent nitrogen, 3 percent helium, 55 percent metha...

A: Assume the mass of the mixture as 100 grams.Given mass of Nitrogen is 10% of mixture which equals 10...

question_answer

Q: Steam enters a turbine a 3 MPa and 500 degrees C, then expands in a reversible adiabatic process and...

A: Given Data:Process: reversible adiabatic process

question_answer

Q: What number would you divide by to calculate the mean of 3, 4, 5, and 6?

A: The mean or average of a given data set is calculated by first finding the sum of given data values ...

question_answer

Q: The spoked wheel of radius r 625 mm is made to roll up the incline by the cord wrapped securely arou...

A: Draw the schematic diagram of the system. 

question_answer

Q: A load of 150 lbs is exerted on a piston confining oil in a circular cylinder with an inside diamete...

A: Write the expression to obtain the area of the piston. 

question_answer

Q: A spring-loaded piston–cylinder device contains a mixture of gases whose pressure fractions are 25 p...

A: Given Information:Pressure fraction of Neon fNe=0.25Pressure fraction of Oxygen fO2=0.50Pressure fra...

question_answer

Q: Find the temperature of the following using the ideal gas law:(a) water, P=10KPa, v=30m^3/kg(b) wate...

A: According to question we have to use ideal gas law, but the parameters are given for water. we canno...