Choked nozzle and thrust correction - turbojet, Other Engineering

Assignment Help:

Choked Nozzle

Considering the formula for thrust under "choked" nozzle conditions:
Thrust =(P-P0 )A + WVj /g    

Where: P = Pressure
P = Ambient Pressure
A = Area
W = Mass Flow
V = Velocity

It can be seen that the thrust can be further affected by a change in the mass flow rate of air through the engine and by a change in jet velocity. An increase in mass airflow may be obtained by using water injection to cool the air and increases in jet velocity by using after-burning.

Changes in ambient pressure and temperature considerably influence the thrust of the engine. This is because of the way they affect the air density and hence the mass of air entering the engine for a given engine rotational speed.

Thrust Correction - Turbojet

To enable the performance of similar engines to be compared when operating under different climatic conditions, or at different altitudes, correction factors must be applied to the calculations to return the observed values to those which would be found under I.S.A. conditions. For example, the thrust correction for a turbo-jet engine is:


Thrust (lb) (corrected) = thrust (lb) (observed) x 30/Po
• Where P0 = atmospheric pressure in inches of mercury (in Hg) (observed) 

30 = I.S.A. standard sea level pressure (in Hg)

 


Related Discussions:- Choked nozzle and thrust correction - turbojet

Matrices for risk analysis, Matrices for risk analysis: NFPA 551 descr...

Matrices for risk analysis: NFPA 551 describes a technique of using matrices for risk analysis.  Such matrices are quite commonly used in the UK for assessing risk but, fortun

Power engine - aircraft maintenance, Power Engine: Power producing engi...

Power Engine: Power producing engines come in two main forms Turboprop and turboshaft. a. Turboprop Engines. Turboprop engines extract most of the energy from the gas stream

Testing of propellers, Testing After Install After installation of a pro...

Testing After Install After installation of a propeller, the engine must be ground run in order to check the propeller for correct function and operation.  Aircraft propeller in

QMETER, Explain how a Q-meter can be used to measure resistance inductance ...

Explain how a Q-meter can be used to measure resistance inductance and capacitance??

Propeller spinners, PROPELLER SPINNERS All modern propeller-driven aero...

PROPELLER SPINNERS All modern propeller-driven aeroplanes have spinners over their propeller hubs. These spinners have the dual aerodynamic function of streamlining the engine

Falling weight impact testing , Drop-weight impact towers are frequently us...

Drop-weight impact towers are frequently used to generate low velocity impact damage. Typically, the falling mass will be instrumented, containing a load-cell for measuring the lo

Cro probes, #questiodescribe different types of cro probes

#questiodescribe different types of cro probes

Corporate finance, Firm A needs to purchase a new machine. If the machine i...

Firm A needs to purchase a new machine. If the machine is purchased, it will replace an old machine purchased 10 years ago for €105,000 and which is being depreciated on a straight

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd