Kaveri & Aero-Engine: News & Discussion

vasu_ray · Post by **vasu_ray** » 08 Aug 2011 08:12

Another drawback is they are very noisy

Air Mexico recently used Ethanol for pax flight, now its an opportunity to start using other fuels in Kaveri

BEML can build heavy earth moving equipment using this with higher power/weight than diesel engines which potentially might make them air transportable

vina · Post by **vina** » 08 Aug 2011 10:06

thammu wrote:Railway uses a engine for driving an alternator which feeds a electrical traction motor, mounted on wheels. Railway will definitely be interested in any compact engine. Presently, the engine driving the most powerful diesel locomotive has a rating of 4000HP. Kaveri will definitely will be more powerful.

The limiting factor are:
1. Railway uses diesel as fuel. They will now have to stock Aviation fuel also.
2. The dimension, specially the height - due to overhead 25 KV transmission lines the height of locomotive cannot be increased.

That modification is very minor. Many aircraft derivative jet engines in power gen, marine etc are run on diesel. In fact I think Kaveri Marin version runs on Diesel!

Yes, given that the IR locos are diesel electric, it is quite easy replace the diesel engine with a gas turbine to drive the generator. But anyway, in that case, you will have to trade off efficiency against the power. Maybe for high speed diesel hauled passenger trains, it would be fine.

juvva · Post by **juvva** » 08 Aug 2011 10:58

thammu wrote:Railway uses a engine for driving an alternator which feeds a electrical traction motor, mounted on wheels. Railway will definitely be interested in any compact engine. Presently, the engine driving the most powerful diesel locomotive has a rating of 4000HP. Kaveri will definitely will be more powerful.

The limiting factor are:
1. Railway uses diesel as fuel. They will now have to stock Aviation fuel also.
2. The dimension, specially the height - due to overhead 25 KV transmission lines the height of locomotive cannot be increased.

Why is the diesel engine not used to drive the wheels directly? Is it not inefficient to convert energy in this manner ( mech -> elect ->mech) ??

neerajb · Post by **neerajb** » 08 Aug 2011 11:14

Wasn't the TGV envisaged as GT-electric, but after the 1973 oil crisis reverted to electric only? How economically viable kaveri would be to power indian locomotives, taking into account the bottomline on which IR operates.

Cheers....

vina · Post by **vina** » 08 Aug 2011 12:23

Why is the diesel engine not used to drive the wheels directly? Is it not inefficient to convert energy in this manner ( mech -> elect ->mech) ??

Transmission becomes complex (multiple bogies need to be driven), the gearbox and other mechanicals add weight, plus prime mover is not directly connected to the drive, speed control becomes easier when you go diesel-electric route (google for it.. most engines went diesel electric or diesel hydraulic long ago, despite the lower efficiency of that kind of drive).

vina · Post by **vina** » 08 Aug 2011 12:25

neerajb wrote:Wasn't the TGV envisaged as GT-electric, but after the 1973 oil crisis reverted to electric only? How economically viable kaveri would be to power indian locomotives, taking into account the bottomline on which IR operates.

Cheers....

For high speed passenger trains in non electric sections niche, yes, there is a possible play . Not much otherwise . For plain vanilla goods and passenger hauling , nothing will beat the SDRE Diesel.

NRao · Post by **NRao** » 08 Aug 2011 16:19

vina wrote:
thammu wrote:Railway uses a engine for driving an alternator which feeds a electrical traction motor, mounted on wheels. Railway will definitely be interested in any compact engine. Presently, the engine driving the most powerful diesel locomotive has a rating of 4000HP. Kaveri will definitely will be more powerful.

The limiting factor are:
1. Railway uses diesel as fuel. They will now have to stock Aviation fuel also.
2. The dimension, specially the height - due to overhead 25 KV transmission lines the height of locomotive cannot be increased.
That modification is very minor. Many aircraft derivative jet engines in power gen, marine etc are run on diesel. In fact I think Kaveri Marin version runs on Diesel!

Yes, given that the IR locos are diesel electric, it is quite easy replace the diesel engine with a gas turbine to drive the generator. But anyway, in that case, you will have to trade off efficiency against the power. Maybe for high speed diesel hauled passenger trains, it would be fine.

More out of curiosity, in that case, they should be able to power a tank with the same? A smaller version perhaps?

NRao · Post by **NRao** » 08 Aug 2011 16:26

juvva wrote: Why is the diesel engine not used to drive the wheels directly? Is it not inefficient to convert energy in this manner ( mech -> elect ->mech) ??

Each one by itself is not as efficient. The combo is what provides the benefit - the best of both the worlds.

arunsrinivasan · Post by **arunsrinivasan** » 08 Aug 2011 17:02

NRao wrote:More out of curiosity, in that case, they should be able to power a tank with the same? A smaller version perhaps?

I asked the same question some months back in the build your tank thread never got an answer. What are the pros & cons of using Diesel Electric hybrid engine to power a tank? I asked Unkal Googal too ... but didnt get a response

SaiK · Post by **SaiK** » 08 Aug 2011 17:57

Any possibility of bharat pack tank engine, that hopefully designed to use any kind of fuel - petrol, deisel, ethanol etc.. [actually m1 abrahams are], would be more suitable for noise, speed controls and traction, and other mechanical properties specifically suited for rail system?

noise is one area that should be a concern.. else, it would be used only for goods.

thammu · Post by **thammu** » 08 Aug 2011 20:08

Why is the diesel engine not used to drive the wheels directly? Is it not inefficient to convert energy in this manner ( mech -> elect ->mech) ??

Smaller diesel locomotive, like shunting engines use direct transmission. But for smoother (jerkless travel) of over 2000 ton loads electric motors become essential.

PratikDas · Post by **PratikDas** » 08 Aug 2011 21:03

arunsrinivasan wrote:
NRao wrote:More out of curiosity, in that case, they should be able to power a tank with the same? A smaller version perhaps?
I asked the same question some months back in the build your tank thread never got an answer. What are the pros & cons of using Diesel Electric hybrid engine to power a tank? I asked Unkal Googal too ... but didnt get a response

[Pulse width modulation] Electric motors can be switched on and off to control precisely the average output torque. This would drastically reduce the need for transmission gearing. So you wouldn't have to carry the weight or volume of a large gear box. You can accelerate smoothly from stop or to a stop, or compensate for change in slope quiet effortlessly, i.e. just by changing the ratio of the ON time to the OFF time. All you would need is a powerful electric motor and a bank of IGBTs

IGBT-Module (IGBTs and freewheeling diodes) with a rated current of 1,200 A and a maximum voltage of 3,300 V

As you can see here, huge currents and/or voltages are not an issue.

abhik · Post by **abhik** » 08 Aug 2011 21:06

DRDO officials told PTI that the Railways were showing keen interest in the programme as gas-turbine engines were the best and most fuel efficient

That's not really true is it?

chackojoseph · Post by **chackojoseph** » 08 Aug 2011 21:20

IMO, these may be used for long hauls only. I found out that TGV used Diesel and later switched on to electricity. US found that it can be run on left over petroleum. Canadian Bombardier has demonstrated it with diesel. Russians are using LNG. So, fuel should not be a constrain.

The other fact I could gather is that it was used in 1950's and is being currently actively considered in US and Russia.

One more point is that it might be inefficient, but, could be thebest solution for greater loads and speeds.

So, I guess IR is planning to look into the prospect in line with rest of the world.

Abhibhushan · Post by **Abhibhushan** » 08 Aug 2011 21:44

NRao asked

... use of gas turbine for tanks.

M1 Abraham is powered by a Honeywell gas turbine.

Brando · Post by **Brando** » 08 Aug 2011 22:04

thammu wrote:Railway uses a engine for driving an alternator which feeds a electrical traction motor, mounted on wheels. Railway will definitely be interested in any compact engine. Presently, the engine driving the most powerful diesel locomotive has a rating of 4000HP. Kaveri will definitely will be more powerful.

The limiting factor are:
1. Railway uses diesel as fuel. They will now have to stock Aviation fuel also.
2. The dimension, specially the height - due to overhead 25 KV transmission lines the height of locomotive cannot be increased.

The Kaveri engine is designed specifically for aviation and is meant to displace significant amounts of air to generate forward acceleration. What you want is a purpose built Turboshaft engine that can drive a generator reliably and has a good Torque profile. The Engine variant that they are developing for Marine use would be more suited for this purpose than vanilla Kaveri.

However, there are much better engines than Kaveri to choose from if IR wants to put turbines on its engines, the best option would be something from GE but they would probably make a helluva racket when a Train pulls up to a station.

The "best" solution would be an all electric solution where they don't need to be burning fuel in any form.

Brando · Post by **Brando** » 08 Aug 2011 22:18

arunsrinivasan wrote: What are the pros & cons of using Diesel Electric hybrid engine to power a tank?

Generally:

Pros:
More efficient, less fuel consumed than vanilla diesel, lesser overall weight (depends), lesser maintenance requirements (usually). transmission not required as uniform torque at ALL speeds.
Cons:
Much more complex to maintain and repair, still using a diesel engine, larger footprint (depends).

The below picture should give you a good idea:

Brando · Post by **Brando** » 08 Aug 2011 22:20

abhik wrote:
DRDO officials told PTI that the Railways were showing keen interest in the programme as gas-turbine engines were the best and most fuel efficient
That's not really true is it?

How can you tell ?

SaiK · Post by **SaiK** » 09 Aug 2011 01:30

fuel cells use should be of interest for railways.

ramana · Post by **ramana** » 09 Aug 2011 03:10

Maybe the Ind Railways want to use them for captive electric gen plants?

shukla · Post by **shukla** » 09 Aug 2011 05:28

Kaveri Engine Project
MOD Press release

The Defence Research and Development Organisation (DRDO) has made no agreement with a French firm to develop the Kaveria aero engine to be used for the Light Combat Aircraft, Tejas. However, DRDO is negotiating with M/s Snecma, France for co-development and co-production of Kaveri aero engine for the Light Combat Aircraft (LCA) Tejas MK-II. The project proposal will be put up for Cabinet Committee on Security (CCS) approval after the completion of price negotiation.

Indian Air Force (IAF) has been consulted at every stage and is part of negotiation. IAF has cleared the Kaveri engine co-development proposal with M/s Snecma, France. The draft engine technical specification has been examined and cleared by IAF. IAF has further suggested that the engine design should have minimal impact on the LCA Tejas airframe for future retrofitment.

This information was given by Defence Minister Shri A.K. Antony in a written reply to Shri Francisco Sardinha in Lok Sabha today.

vina · Post by **vina** » 09 Aug 2011 05:40

Gas Turbines are very efficient compared to equivalent diesel or petrol engines but the catch is the revs have to be fixed

Well, typically in a GT (until the turbine material advances), the heat addition happens at a lower average temp (and pressure) than what happens in a Diesel. The Carnot efficiency was therefore less as well.

Yes ideal GT is a constant POWER engine, while a Diesel is a constant Torque engine (the induction motor is a constant RPM engine). The GT are more difficult to throttle and speed control vs a Diesel engine.

GeorgeM · Post by **GeorgeM** » 09 Aug 2011 05:48

arunsrinivasan wrote:
NRao wrote:More out of curiosity, in that case, they should be able to power a tank with the same? A smaller version perhaps?
I asked the same question some months back in the build your tank thread never got an answer. What are the pros & cons of using Diesel Electric hybrid engine to power a tank? I asked Unkal Googal too ... but didnt get a response

arunsrinivasan, please refer to this LINK about a Caterpillar diesel-electric hybrid dozer, which I believe may be the closest you can get to a hybrid suited for a tank. Yo can see some of the advantages listed as well.

Talking about Pros and Cons generally electric motors provide higher torque for a larger range of speeds. What I mean in other words is that they provide a flatter torque curve than the peaking kind you see with Compression Ignition engines. This is especially so at very low speeds close to 0 rpm. CI engines thus are forced to use transmissions to run at higher engine speeds and get the vehicle moving from 0 wheel rpm. There are several reason for electric motor having this torque advantage, one is that in CI engines the pistons move linear which is converted to rotary motion by the crank, secondly the fuel explosions inside are intermittent while in a motor the magnetic field is either constant or at a much higher frequency (less gap between energy inputs) Please refer to this LINK to see the torque map comparison. All these translate to higher fuel efficiency, smaller engine, longer engine life (engine runs at more or less constant rpm) and quicker acceleration.

Also please refer to the good post by PratikDas on Pulse Width Modulation which helps to eliminate transmissions for hybrids.

To think of the cons, there is some serious high voltage running through those wires. In case the tank is hit now you have a very dangerous environment with sparks and loose wires with high voltages around you. If these risks are tackled, I am sure hybrid will see service in tanks. Hope this helped

neerajb · Post by **neerajb** » 09 Aug 2011 07:24

^^^^ Wonderful post. Thanks.

Cheers....

thammu · Post by **thammu** » 09 Aug 2011 07:53

Also please refer to the good post by PratikDas on Pulse Width Modulation which helps to eliminate transmissions for hybrids

Indian Railways is already using PWM technique as does other modern railways in 3 phase drive on their locomotives and EMU.

arunsrinivasan · Post by **arunsrinivasan** » 09 Aug 2011 15:30

Thanks for the replies. Sorry for going OT, maybe these posts should be moved to the build your tank thread

abhik · Post by **abhik** » 10 Aug 2011 22:50

Brando wrote:
abhik wrote: That's not really true is it?
How can you tell ?

Let me rephrase that. How many locos currently in production use gas turbine engines?

Leo.Davidson · Post by **Leo.Davidson** » 11 Aug 2011 02:01

abhik wrote:Let me rephrase that. How many locos currently in production use gas turbine engines?

None. And they are highly fuel inefficient to be used on locomotive. Man, I got to have what these guys are smoking; coming up with bizarre implementations.

jaladipc · Post by **jaladipc** » 11 Aug 2011 03:37

Leo.Davidson wrote:
abhik wrote:Let me rephrase that. How many locos currently in production use gas turbine engines?
None. And they are highly fuel inefficient to be used on locomotive. Man, I got to have what these guys are smoking; coming up with bizarre implementations.

Not really.
There used to be a bunch of GT locos used to ferry people and goods until the late 70`s.
There was a prototype from bombardier during 2000 or something.

The only problem with GT on locos is wastage of fuel while idling. They are much efficient for high speed locos and on long routes..
To make them more economical,its wise to use natural gas or some bio fuels.

vasu_ray · Post by **vasu_ray** » 11 Aug 2011 04:25

Ok, if idling is the problem, it can feed power into the electrified network, there is a precedent to this in Swiss mountain railways they use power from two trains coming downhill employing regenerative braking helping power one train going up the hills

until our MW shortage is addressed, railways can use GT's

or lay a undersea insulated power line from Iran where the gas fired power plants run instead of pumping gas with the IPI which is better than no gas at all

Ashwin B · Post by **Ashwin B** » 12 Aug 2011 07:17

Jaladip might be talking about this:
http://en.wikipedia.org/wiki/JetTrain

Based on the design of Acela trains that run between Boston and Washington DC.
The JetTrain " was designed to use petroleum based fuel to power a diesel engine and multiple turboshaft engines for higher speeds." Quote from the Wikipedia page.

vic · Post by **vic** » 12 Aug 2011 11:20

I think that LCA with present Kaveri engine should be developed as an AJT

abhik · Post by **abhik** » 12 Aug 2011 18:52

Leo.Davidson wrote:... Man, I got to have what these guys are smoking; coming up with bizarre implementations.

Exactly.

thammu · Post by **thammu** » 14 Aug 2011 07:38

The Western corridor is non-electric where as the eastern is going to be electric. This is exactly where Railways is showing its interest. Kaveri though inefficient can provide the power to pull 100 carriages with Dual-Stack containers at 100 kmph.

That was the earlier plan. It was finally decided to go for electric traction on both corridors, by having higher pantograph in locos hauling double stacked containers.

Will · Post by **Will** » 14 Aug 2011 09:58

Whats with this new drdo initiative of building a jet engine. Any further details on it?

Pogula · Post by **Pogula** » 14 Aug 2011 11:17

AFAIK, electric motors are the most efficient option for locomotives right now. And, using a variation of Kaveri in a tweaked and controlled environment of electricity generation for the Railway Electrical Grid is far more practical and effective for Indian Railways, IMHO, as opposed to using them to propel individual trains.

sivab · Post by **sivab** » 16 Aug 2011 23:24

Kaveri being tested for takeoff thrust of 8257kg (81kN) at Mach 0, sea level.

http://4.bp.blogspot.com/-snnC1zt3FfI/T ... C03706.JPG

http://chhindits.blogspot.com/2011/08/k ... -makc.html

SaiK · Post by **SaiK** » 17 Aug 2011 06:02

Growing to 100kN is definitely feasible with SC blades, blisks and high temperature coatings and blade designs to drive maximum thrust. If GE & Snecma has done it, we can do it too.. and that is how we came to be testing the 81kN. Now, one may argue it took soooo long.. I ask why not? a little bit more proper management and budgeting would have helped it mature a bit long back.

Furthermore, a slow progress but steady towards to achieve the goals matters a lot in turbines.

NRao · Post by **NRao** » 17 Aug 2011 06:18

That small thing called 80:20 sometimes bites. 20 at times accounts for 80 of time/funds.

Such is life.

Doable? Has to be done.

VinodTK · Post by **VinodTK** » 17 Aug 2011 07:07

DRDO says its Kaveri engine can power combat drones, warships and possibly trains

NEW DELHI: So what if it cannot power fighter jets as of now, it's perfectly suitable for combat drones, warships and possibly even trains! Or, so the never-say-die Defence Research and Development Organization (DRDO) is now proclaiming as far as its Kaveri engine is concerned.

DRDO officials say the Kaveri aero-engine, which incidentally is over 22 years in the making by now with a sanctioned cost of Rs 2,893 crore, can power unmanned combat aerial vehicles (UCAVs) because they "do not require the kind of higher thrust" needed for the indigenous Tejas LCA (light combat aircraft).

"Nine prototypes of Kaveri engine and four prototypes of Kaveri Core (Kabini) engines have been developed with over 2,000 hours of testing...the engine is proven with almost 80 kilonewtons (kN) of thrust now, which is enough for our UCAVs (Tejas requires 90 kN)," said an official.

This comes even as DRDO has now begun preliminary work on developing stealth UCAVs, under the secretive 'autonomous unmanned research aircraft' programme. This UCAV will weigh less than 15 tonnes, fly at altitudes of 30,000 feet and fire missiles and bombs with precision, as earlier reported by TOI.

DRDO has also come up with a modified Kaveri version, by "designing a free-power turbine to generate shaft power", for propulsion of warships. The Navy, as per DRDO, has shown "a lot of interest" in the engine which has a 12 MW power output.

"With Kaveri, we have proven several gas turbine technologies for a variety of applications. Indian Railways is also interested in knowing whether Kaveri can be used for powering trains," said the official.

DRDO is now also trying to tie up with French company Snecma to jointly develop the "90kN thrust class of upgraded Kaveri engines" for the future requirements of IAF. But the fact remains that the Kaveri project's dismal performance has forced India to ink a $822 million contract for 99 General Electric's F-414 engines, with an option to go for another 49 engines at a later stage, to power the Tejas Mark-II version.

While the first 20 Tejas will be powered by GE-404 engines, the next six Mark-II squadrons (16-18 jets in each) will have the new more powerful GE F-414 engines. Under the LCA project, which itself has been 28 years in the making with an almost 3,000% jump in overall developmental costs, IAF hopes to have its first two fully-operational Tejas squadrons based at the Sulur airbase (Tamil Nadu) by 2015 now.