Exhaust jet mixing - aircraft design, Other Engineering

Assignment Help:

Exhaust Jet Mixing:

Figure shows that the noise from the exhaust jet is the main contributor to the total noise generated by a low by-pass ratio turbo-fan. For a turbo-jet the noise from the exhaust is an even greater contributor to the whole. Fortunately it is comparatively easy to reduce the noise by increasing the mixture rate of the exhaust gases with the atmosphere. This can be achieved by increasing the contact area of the atmosphere with the gas stream by incorporating a corrugated or lobe-type suppresser in the propelling nozzle.

The addition of a corrugate nozzle gives the effect shown in figure 7.16. In the corrugated nozzle, atmospheric air flows down the outside corrugations and into the exhaust jet to promote rapid mixing. In the lobe-type nozzle, the exhaust gases are divided to flow through the lobes and a small central nozzle. This forms a number of separate exhaust jets which rapidly mix with the air entrained by the suppresser lobes. Deep corrugations or lobes give a greater noise reduction, but the penalties incurred limit the size of the suppressers, eg. to achieve the required nozzle area, the overall diameter of the suppresser may have to be so large that excessive drag results.

A nozzle may be designed to give a large reduction in noise level, but this could incur a considerable weight penalty due to the additional strengthening required. A compromise that gives a noticeable reduction in noise level with the minimum sacrifice of engine thrust or increase in weight is, therefore, the designer's aim.

 

 

1979_Exhaust Jet Mixing.png


Related Discussions:- Exhaust jet mixing - aircraft design

Digital electronic.., design a 32:1 multiplexer using 16:1 multiplexer

design a 32:1 multiplexer using 16:1 multiplexer

Function intersect - set operations, Function intersect - set operations: ...

Function intersect - set operations: The function intersect returns, additionally to the vector having the values in the intersection of v1 and v2, an index vector into v1 and

Composite materials - rotational stability equations, Rotational stability ...

Rotational stability equations  The torque T applied to any rigid vehicle with moving c.g. is in general determined by T = ∂HVE/∂t|E + uvE ×MugE where E is the inertial a

Life cycle of a product from raw materials, The Task: This project is a...

The Task: This project is a 50% of the whole assessment of the course. You are required to assess a life cycle of a product from raw materials, through the supply chain, manufa

Electronics devices and circuits, With the help of circuit diagram and the ...

With the help of circuit diagram and the waveforms,explain the working of a negative clipper with positive biasing voltage.also explain the Same concept in series clipper circuit

Security Analysis & Portfolio management, ABC Ltd. has an investment opport...

ABC Ltd. has an investment opportunity available which will involve a capital outlay in each of the next 2 years and which will produce benefits during the following 3 years. A sum

Cash mangement, how to do a cash management project report ,including probl...

how to do a cash management project report ,including problems?example?

What is the difference between real money & nominal money?, What is the dif...

What is the difference between real money & nominal money?  Moderate cash is relevant to the evaluate of keeping track of. nominal figure is what is published on the expenses. w

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