Choked nozzle and thrust correction - turbojet, Other Engineering

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)

 

Posted Date: 9/11/2012 7:51:00 AM | Location : United States







Related Discussions:- Choked nozzle and thrust correction - turbojet, Assignment Help, Ask Question on Choked nozzle and thrust correction - turbojet, Get Answer, Expert's Help, Choked nozzle and thrust correction - turbojet Discussions

Write discussion on Choked nozzle and thrust correction - turbojet
Your posts are moderated
Related Questions
In the Aircraft Performance course, the aircraft was assumed to be in a steady-state (e.g. steady  cruise, climb, turn, glide), with the forces and moments balanced. The subject of

Q. Describe the electro slag welding process.                                                   OR        Describe electro slag welding process. What are the speci

THE USER INTERFACE

how to identify the capital structure?

Beta coefficients and standard deviation may be used as indicators of risk

the crate has a mass M and is subjectedto towing P acting at an angle t1 with the horizontal.if the coefficient of static friction is k,determine the magnitude of p to just start

simplify using quine Mccluskey tabulation algorithm and find out the number of primes implicants f(a,b,c,d)=(2.3,4,5,13,15)+d(8,9,10,11) in logic design

explain any two finishing processes in detail with neat diagram

explain coil ?

Abrasive Grit This method of compressor cleaning involves injecting an abrasive grit into the engine at selected power settings ( Figure 21.30.)grit used may be ground walnut s