Question

**As a propulsion engineer, you are tasked with testing
the turbojet engine of an aircraft to determine its performance
characteristics. The turbojet engine is analyzed on an
air-standard basis based on the Brayton cycle. Air, with a velocity
of 265 m/s and volumetric flow rate of 230 m ^{3}/s, enters
the diffuser at 18 kPa, -57^{o}C, and exits at 30
kPa. The compressor pressure ratio is 15 to 1. The
maximum temperature exiting the combustor is 1087^{o}C. The
pressure exiting the nozzle is 18 kPa. The compressor, turbine and
nozzle have efficiencies of 87%, 89% and 97%, respectively.
Applying air standard assumptions,
determine: **

**A. The schematic and T-s diagrams**

**B. The power input of the compressor**

**C. The velocity at the nozzle exit**

**D. The mass flow rate of air into the
engine**

**E. The thrust developed by the engine**

**F. The propulsive efficiency of the engine**

Answer #1

A turboprop engine consists of a diffuser, compressor,
combustor, turbine, and nozzle. The turbine drives a propeller as
well as the compressor. Air enters the diffuser with a volumetric
flow rate of 63.7 m3/s at 40 kPa, 240 K, and a velocity
of 180 m/s, and decelerates essentially to zero velocity. The
compressor pressure ratio is 10 and the compressor has an
isentropic efficiency of 85%. The turbine inlet temperature is 1240
K, and its isentropic efficiency is 85%. The...

Hot exhaust gases 260 kPa, 900o to the nozzle of a
turbojet engine
It enters under C and 80 m / s conditions and exits at 85 kPa
pressure. Assuming isentropic efficiency as 95% and exhaust gases
as air,
a) the velocity of the gases from the nozzle, and
b) determine the outlet temperature.

A turbojet engine is fitted to an aircraft flying at M = 0.85 in
conditions where the
ambient temperature is 216 K and the ambient pressure is 18.75
kPa. You are to
assume adiabatic flow and isentropic conditions.
The following data on the engine are known:
Compressor pressure ratio ?? = 12
Combustion chamber efficiency ?? = 1
Turbine Inlet temperature ?4 = 1796 ?
Calculate:
a) The total temperature and pressure at entry to the
compressor. (6 Marks)
b)...

A turbojet aircraft is flying with a velocity of 320 m/s at a
certain altitude, where the ambient conditions are 32 kPa and
-32°C. The pressure ratio across the compressor is 12, and the
temperature at the turbine inlet is 1400K. Air enters the
compressor at a rate of 40 kg/s, and the and the jet fuel has a
heating value of 42700 kJ/kg. Assuming ideal operations for all
components and constant specific heats for air at room temperature,
(Cp=1.005...

An aircraft turbojet engine compressor draws in air at -40oC,
36kPa and compresses it adiabatically to 222.4oC, 504kPa. The
volume flow rate of air at compressor inlet is 110 m3 .s-1, the
intake air velocity is 140 m.s-1 and the exit air velocity is 20
m.s-1. Compute the power required by the
compressor.

Air enters the diffuser of a jet engine operating at a steady
state at a pressure of 18 kPa, a temperature of 213 K and a
velocity of 285 m/s. The air flows adiabatically through the
diffuser and exits at a temperature of 240 K. Using the ideal gas
model for the air, please determine the velocity of the air at the
diffuser exit, in m/s.

Air enters the compressor of an air-standard Brayton cycle with
a volumetric flow rate of 60 m3/s at 0.8 bar, 280 K. The
compressor pressure ratio is 17.5, and the maximum cycle
temperature is 1950 K. For the compressor, the isentropic
efficiency is 92% and for the turbine the isentropic efficiency is
95%.
Determine:
(a) the net power developed, in kW.
(b) the rate of heat addition in the combustor, in kW.
(c) the percent thermal efficiency of the cycle.

I ONLY NEED ANSWERS TO F.) AND G.)
I SOLVED THE REST. THANK YOU!
The Boeing 747 has a cruising altitude of 45,000 feet and
cruising speed of 275 m/s. At this elevation, the temperature and
pressure according to the US Standard Atmosphere (air properties as
a function of altitude) are 220K and 1.8x104 Pa, respectively. The
engines are steady state devices that can be modeled using the 1st
Law of Thermodynamics with air (ideal gas) as the working fluid...

A jet engine is operating at an altitude of 7000 m. The mass of
air passing through the engine is 46 kg/s and the heat addition in
the combustion chamber is 500 kJ/kg. The cross-sectional area of
the combustion chamber is 0.5 m2, and the air enters the chamber at
a pressure of 80 kPa and a temperature of 80°C. After the
combustion chamber, the products of combustion, which can be
assumed to have the properties of air, are expanded...

1) A nozzle is a device for increasing the velocity of a
steadily flowing stream of fluid. At the inlet to a certain nozzle
the enthalpy of the fluid is 3025 kJ/kg and the velocity is 60 m/s.
At the exit from the nozzle the enthalpy is 2790 kJ/kg. The nozzle
is horizontal and there is negligible heat loss from
it.
(i) Find the velocity at the nozzle exit.
(ii) If the inlet area is 0.1 m2 and specific volume...

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