Kaveri Engine

[Karthi]

You are missing LIMITED FLIGHT ENVELOPE part.

I didn't understand the part , are you saying about the flight envelop of Aircraft

 

[Aaj ka hero]

I didn't understand the part , are you saying about the flight envelop of Aircraft

Yes, this mean it can't perform at certain atmosphere level with desired performance.
The big problem right now is materials and also go to defence decode there you will find kaveri problems and solutions.

 

[Karthi]

Yes, this mean it can't perform at certain atmosphere level with desired performance.
The big problem right now is materials and also go to defence decode there you will find kaveri problems and solutions.

Ok , we need to fix it . One of the major reason for dropping Kaveri was under power only produced 80 KN instead. 90 KN . So in a twin Engine configuration we can overcome the problem of thrust . Thats what I tried to convey

 

[Aaj ka hero]

Ok , we need to fix it . One of the major reason for dropping Kaveri was under power only produced 80 KN instead. 90 KN . So in a twin Engine configuration we can overcome the problem with thrust . Thats what I tried to convey

First we need to fix that chronic bypass ratio, just see 0.18 and see other engines.
Also new materials are going to come in future.
With the level of advancement we have done I am sure with little help from inside as well as outside, that magical number for upcoming projects is achievable.
Problem will arise with testing though, it must perform at all levels of it's flight envelop, let's see.

 

[Aaj ka hero]

I think kaveri is low bypass ratio engine specifically designed as low by pass ratio

Even for low bypass ratio, it is not good must be in the range of 0.4 to 0.6 and this is what going to be done on k-9 series.
Just wait, building blocks are already there.

 

[IndianHawk]

Ok , we need to fix it . One of the major reason for dropping Kaveri was under power only produced 80 KN instead. 90 KN . So in a twin Engine configuration we can overcome the problem of thrust . Thats what I tried to convey

Kaveri design goal was always 81 KN wet thrust. Original f404 was 79 KN on which kaveri was benchmarked. But lca got overweight due to overdesign of some parts like landing gear.

 

[dude00720]

Nice summary on Engine design and Kaveri issues. Must Watch.
Video courtesy ~ Defence Decode

 

[no smoking]

Chinese had no platform to test engine back then [-- Redacted --]

[-- Redacted --]

Most of testing of WS-10 was carried out in Chinese high altitude testing facility.
In 2000, Chinese purchased an IL-76 engine flying test bed from Russia and the plane was sent to China and put into service in 2005. Since then WS-10A (the real one for J-11B and other jets) was tested on this plane.

So, the so called "2010 Russian tested Chinese engine" is purely your fantasy.

And you have bought entire su35 so that Russian continue to support your engines also because j20 is a dud. Stop lying.

[Moderation Edit: -- No personal attacks --]

How can Russian support Chinese engine with only 24 Su-35?
By your logic, buying 36 Rafael because Tejas is a dud, right?

 

[vampyrbladez]

That is why I likes Indian fanboy. They just like to live in their own dream.
Most of testing of WS-10 was carried out in Chinese high altitude testing facility.
In 2000, Chinese purchased an IL-76 engine flying test bed from Russia and the plane was sent to China and put into service in 2005. Since then WS-10A (the real one for J-11B and other jets) was tested on this plane.

So, the so called "2010 Russian tested Chinese engine" is purely your fantasy.



Are you that stupid? How can Russian support Chinese engine with only 24 Su-35?
By your logic, buying 36 Rafael because Tejas is a dud, right?

[Moderation Edit: -- No personal attacks --]

WS-10 has a very short engine life. That's why your military still buys AL-31FN series engines till today.

Now your J 20 is underpowered and needs a significant boost. Thus the AL-41F1S engine is to be procured under the cover of the sale of 24 Su 35BM as aftersales support and 'spares'.

 

[Dovah]

Guys, avoid personal attacks. Reply to posts on the merit of content and report offending posts, do not indulge in tit-for-tat.

 

[Karthi]

Kaveri design goal was always 81 KN wet thrust. Original f404 was 79 KN on which kaveri was benchmarked. But lca got overweight due to overdesign of some parts like landing gear.

But Kaveri failed in 50-81 KN thrust level also .

 

[Aaj ka hero]

But i think it is better design as more air pass from core than bypass it.. Mor like futuristic design.. Our problem is with fan design which they have changed like presented in expo and new combustion chamber as per latest ..

High bypass is good on two points basis,according to me.
First, it gives more range.
Second, it also cool the engine which is critical.
A turbojet is cool only on high altitudes because whatever air you have, you need it for thrust, good for mig-25 and family.
Not good for AMCA and family.
And the fan design which you are talking about if I am not wrong was the one shown in defexpo as well as in youtube, then that design is ALSO FOR bypass increase ratio only.
So, the fan design is for good maneuverability as well as high and efficient thrust.

 

[Karthi]

From DDR one of the major problem of Kaveri Engine is Flutter of fan blades . Flutter is applicable to all kind of blades using in jet engine . Mode shape is identified as the most important contributor to determining the stability of a blade design.

Flutter is the self excited vibration of blades due to structural dynamics or aerodynamic force's.it may result in Blade lose immediately or high cycle fatigue in the long run. In simple terms Flutter is a condition in which the fluid around the structure acts in a destabilizing manner (i.e. exciting the system) instead of damping the oscillations.

Flutter is a problem because of phase difference between the blades when they are vibrating .A Simple harmonic motion is natural but when the material starts to vibrate more than a point (Flutter point) it will result in a self oscillation and eventually failure. The blades interact with other blades in the same row due to the fluid presence. This kind of blade interaction if often referred as aerodynamic coupling.The most common source of unsteady forces is due to the interaction between rotating blade rows and non-rotating blade rows (blade row interaction).

Each aeroelastic mode has a different inter-blade phase angle. The inter-blade phase angle affects the phase between the local unsteady flow and local blade motion which in turn affects the unsteady aerodynamic work done on the blades. Adverse phase angles can lead to positive work being performed on the blades which results in flutter.

So in my conclusion the design of Kaveri Engine itself is faulty . May be the Flutter problem of fan can be Eliminated with the new Fan .

This kind of Flutter is applicable to even large aircrafts.

This video may be helpful

 

[fire starter]

View attachment 45916

From DDR one of the major problem of Kaveri Engine is Flutter of fan blades . Flutter is applicable to all kind of blades using in jet engine . Mode shape is identified as the most important contributor to determining the stability of a blade design.

Flutter is the self excited vibration of blades due to structural dynamics or aerodynamic force's.it may result in Blade lose immediately or high cycle fatigue in the long run. In simple terms Flutter is a condition in which the fluid around the structure acts in a destabilizing manner (i.e. exciting the system) instead of damping the oscillations.

Flutter is a problem because of phase difference between the blades when they are vibrating .A Simple harmonic motion is natural but when the material starts to vibrate more than a point (Flutter point) it will result in a self oscillation and eventually failure. The blades interact with other blades in the same row due to the fluid presence. This kind of blade interaction if often referred as aerodynamic coupling.The most common source of unsteady forces is due to the interaction between rotating blade rows and non-rotating blade rows (blade row interaction).

Each aeroelastic mode has a different inter-blade phase angle. The inter-blade phase angle affects the phase between the local unsteady flow and local blade motion which in turn affects the unsteady aerodynamic work done on the blades. Adverse phase angles can lead to positive work being performed on the blades which results in flutter.

So in my conclusion the design of Kaveri Engine itself is faulty . May be the Flutter problem of fan can be Eliminated with the new Fan .

This kind of Flutter is applicable to even large aircrafts.

This video may be helpful

This new fan will achieve an overall compression ratio of 30:1, Kaveri had a compression ratio of 21.5:1. The fan was touted to be flow distortion tolerant, as in it can suck air from a serpentine intake and can survive supersonic oblique compression shock infront of the intake. flutterence issue has been solved.

 

[Karthi]

This new fan will achieve an overall compression ratio of 30:1, Kaveri had a compression ratio of 21.5:1. The fan was touted to be flow distortion tolerant, as in it can suck air from a serpentine intake and can survive supersonic oblique compression shock infront of the intake. flutterence issue has been solved.
View attachment 45923

Hope So.

 

[darshan978]

Nice summary on Engine design and Kaveri issues. Must Watch.
Video courtesy ~ Defence Decode

the image in thumbnail isn't even ej-200 jet engine that is Russian D30 JET ENGINE.
shows credibility of video.

 

[HariPrasad-1]

View attachment 45827

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3 D printed parts of HAL HTEF Engine . Tge last picture is the 3D printer which printed the Turbine blades , with 3D printing we can accurately manufactur High end fan blades for jet engine.

We are making more and more building blocks of Kaveri engine ready by developing new technologies used in aero engines. New crystal blades, thermal coating, new fan design, new burner design etc. are becoming ready. we should keep developing it by investing more money and manpower. Evenif we are unable to forge a joint venture with any other company, we will be able to realise the engine within next 7 to 8 years. What require is sustained effort and sustain funding.

 

[Alok Arya]

This new fan will achieve an overall compression ratio of 30:1, Kaveri had a compression ratio of 21.5:1. The fan was touted to be flow distortion tolerant, as in it can suck air from a serpentine intake and can survive supersonic oblique compression shock infront of the intake. flutterence issue has been solved.
View attachment 45923

This fan give pressure ratio of 5:1, while being distortion resistant. For a pressure ratio of 30:1 we have to improve all LP and HP stages.

 

[Astra2019]

I did some calculations and I get exact TET

 

[Karthi]

Another major issue of Kaveri Engine us reheat oscillations, which made afterburner completely problematic . It's difficult to spot where exactly the oscillations going to takes place . Today there are methods to find it.


The afterburner is designed so that the flame flows along its axis, away from its walls. Careful placement of the fuel tubes and the ignition source at the front end of the a, where hot but not burning exhaust gas is flowing out of the engine, creates a stable zone in the airflow where air and fuel can mix.

The stable flow ensures that the flame ignites quickly and burns at a consistent location. If the flame moves around, it could set up oscillations that eventually could burn through the jetpipe or damage the end of the exhaust nozzle.