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ME a quick search revealed this but I'm not sure how accurate it is- I suspect it maybe the plastic recruiting pig
http://img535.imageshack.us/img535/9...f5751c45fo.jpg |
Modern Elmo,
The Typhoon intakes are S-shaped along their length. The turbine blades are not visible when looking in the intake at the front. |
ORAC
What is this 'suddenly preferred the Rafale' belonging to an Indian? :8 |
Rafale wins Indian order
First hand experience in India with the Hawk contract says that the contract will hinge on whether the French allow HAL or Mahindra to build the Rafale in India.
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It's easy to see the practical attractiveness of Rafale over Typhoon. Being built by one country, with one main contractor, Rafale has acheived far more of its design capability in less time than Typhoon. India knows it won't have to put up with the riciculous in-fighting that has almost cost Typhoon its very existance over the years. If I were them, I would take a lot of convincing to go for a jet with promised capabilities over one that already has them. Especially given all the broken promises and missed milestones over the years.
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You're probably right, M2. We should have seen this coming years ago!
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Originally Posted by earswentpop
So they don't want the aid. Whatever. Can we have our call centres back? Especially that god-awful one for BT Broadband.
Hell, we might even buy the Typhoon if you do! |
Bombay Duck, are you confident that Rafales can handle newer Chinese fighter aircraft, some of which incorporate patented technology stolen from the F-35?
http://www.codeonemagazine.com/thumb...g&size=gallery Diverterless supersonic inlet From Wikipedia, the free encyclopedia This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (November 2011) Diverterless supersonic inlet A diverterless supersonic inlet (DSI) is a type of jet engine air intake used by some modern combat aircraft to control air flow into their engines. It consists of a "bump" and a forward-swept inlet cowl, which work together to divert boundary layer airflow away from the aircraft's engine while compressing the air to slow it down from supersonic speed. The DSI can be used to replace conventional methods of controlling supersonic and boundary layer airflow, such as the intake ramp and inlet cone, which are more complex, heavy and expensive.[1] Research into the DSI was done by Lockheed Martin in the early 1990s. The first DSI was flown on 11 December 1996, installed on a F-16 Block 30 fighter and replacing aircraft's original intake diverter. The modified F-16 demonstrated a maximum speed of Mach 2.0 and handling characteristics similar to a normal F-16. It was also shown that subsonic specific excess power was slightly improved. A DSI was later incorporated into the design of the Lockheed Martin F-35 Lightning II.[1] The JF-17 Thunder also uses a DSI. Work on the DSI was started in 1999 ( Note the timing. -- Elmo ) with the aim of improving aircraft performance and took almost two years, during which a number of models underwent wind tunnel tests at different speed regimes. It was found that the DSI gave high performance, high total pressure recovery, low integrated distortion and good engine/intake matching.[2] The Lockheed Martin F-35 Lightning II, JF-17 Thunder, Chengdu J-10B and Chengdu J-20 fighters all incorporate DSI. Text below is from Lockheed's "Code One" house organ magazine Code One Magazine: JSF Diverterless Supersonic Inlet: ... Basic research of the inlet concept continued through the mid-1990s. Traditional wind tunnel testing of small plastic inlet models built with stereolithographic techniques augmented a CFD-based development process for the DSI. Engineers made enough technical advances during this period that two US patent applications were filed, one dealing with the overall design and the second dealing with the integration process of the new technology. (Both patents were granted in 1998.) The diverterless inlet designs built and tested with this combination of CFD and small-scale wind tunnel models formed a database of inlet configurations that would subsequently prove valuable to the Lockheed Martin JSF design. ... LM Aeronautics JSF Design Adopts DSI The DSI concept was introduced into the JAST/JSF program as a trade study item in mid-1994. It was compared with a traditional "caret" style inlet. The trade studies involved additional CFD, testing, and weight and cost analyses. The new inlet earned its way into the JSF design after proving to be thirty percent lighter and showing lower production and maintenance costs over traditional inlets while still meeting all performance requirements. The flight tests on the F-16 validated the aerodynamic properties of the inlet, which will be validated further on the upcoming flights of the Lockheed Martin JSF demonstrator aircraft in 2000. The flight test also proved that the analytical performance and inlet flow stability predictions from the CFD analysis matched operations in the real world. The JSF program further refined the production version of the DSI design using these CFD tools. The DSI inlet used on the JSF has evolved through several design iterations. The shaft-driven lift fan on the STOVL JSF required the use of a bifurcated duct with one inlet on each side. The initial version was essentially the same design used on the lower surface of the F-16 rotated up onto either side of the JSF forward fuselage. This design had a cowl that was symmetrical about the centerline of the bump. This version of the inlet appears on the X-35 demonstrator aircraft. Later CFD analysis and testing led to refinements of the design to improve its performance at high angles of attack by shifting the upper and lower cowl lips to take advantage of the side-mounted location and to improve high angle-of-attack performance. This later version has been fully tested in the wind tunnel and will be used on the EMD and on production aircraft.[/SIZE[/I]] |
ME, sort of begs the question; can Typhoon? if no what do you see as one types advantage over the other, if yes why is UK investing in F35 when such technology has been dealt with?
Not the full story by any means I'm sure, but I hope you can see where I'm going |
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Originally Posted by JFZ90
In general, the radar aperture (antenna area) doubles with a 1.41 times increase in diameter. With all else being constant it takes an increase in aperture of 10x to double the range of a radar. Technologies like AESA antennas increase the output and sensitivity of a radar for any given size. Advanced T/R module technology and smaller T/R modules also do that. PESAs generally reduce sensitivity. Both types of ESAs allow instantaneous beam steering and high beam focus. Only the AESA can form multiple beams simultaneously. .
Radar range (in the physics sense) is driven by the total power output of the transmitter, the reflectivity of the target, and the sensitivity of the receiver - not by the antenna aperture. It varies with the fourth power of Tx energy (power squared for the outbound journey, power squared for the return journey); if you want to double the range of a radar, you don't double the antenna size, you up the power output by sixteen. The antenna size is more relevant for main beam width. That and your PRF schedule and pulse-to-pulse detection probabilities drive your scan rate, which drives... a lot of other design decisions. Google "radar range equation". Aperture size only becomes relevant if you're talking about the Tx energy being made up of lots of active array elements which each have a maximum power output - the AESA total Tx energy varies with the aperture size only if you assume identical Tx/Rx modules. All else being equal, the 16x increase in the number of elements required to double your AESA range comes from a x4 radius increase. Of course, an upgrade to the power output of each Tx/Rx module can achieve exactly the same thing - and such improvements keep coming along. Or, you could use a swashplate design, and add more T/R elements for the same frontal diameter. Another thought is that it isn't as simple as "total power per element times number of elements" - not all of the elements will transmit at full power all of the time, for various reasons. I'm not sure how Moore's law affects T/R elements, but I suspect that it's a fast-evolving area (google "graphene" for the latest fun). You may find that a smaller, newer AESA ends up with better performance than a larger, older one. |
My distant recollection is that aperture directional gain makes up part of the Rx gain. This reference tends to agree, with my fading memory:
Radar Systems |
Originally Posted by engineer(retard)
My distant recollection is that aperture directional gain makes up part of the Rx gain.
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HVAL, turbine blades are not visible down the intake - even on the Vulcan. Compressor and fan blades may be.
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Mach Two
Given my background, it pains me to say so, but you have a very strong point! |
True - I was focussing on the "Tx power ** 4" bit. You can do cute stuff with the same-sized antenna to give you better directional gain (see "not all of the elements will radiate with the same power"); but I was focussing on what I thought was a "if you want twice the range you need 10x aperture" argument from the original poster. In other words what i was trying to say was that if you apply the same radar technology to typhoon or rafale, the potentially larger effective aperture of typhoon will be an advantage? At typhoon at 700mm vs rafale at 600mm, the area is potentially 36% larger. This increase is directly proportional to the power returning to the receiver, for equivalent tx power, antenna gain, range and rcs. Does that translate into an 8% benefit in range? |
Bombay Duck, are you confident that Rafales can handle newer Chinese fighter aircraft, some of which incorporate patented technology stolen from the F-35? The IAF is moving on from 1v1 warfare and has invested in "force multipliers" (not sure if this phrase is in common usage) such as AWACS and in-flight refuelling, while now attempting to shore up its superiority in numbers on at least the western front. Moving on to Chinese aircraft: The FC-1/JF-17 may incorporate a DSI but... it's not a game-changer. I'd be interested to know what sort of kit the Chinese have gotten working inside the radome, and if they ever got the SD-10 AMRAAM-equivalent missile working. The J-10 looks fairly good - but again I'm not sure what sort of kit they have in them, and I'm fairly sceptical of internet-based rumours. If there is one aircraft I'm not at all worried about, it's the J-20. If they want to waste money on developing, buying and maintaining "stealth" fighters, more power to them. But all this is just me, and it's a layman's opinion. :) |
BombayDuck.
Er, When you say: "MMRCA is meant to be primarily a strike aircraft.... it is meant to replace legacy Jaguars, supplement new-build Jags and take over from Mirage 2000s in that rol...." According to the Indian AF, MMRCA is a Mig-21 replacement. |
Originally Posted by JFZ90
At typhoon at 700mm vs rafale at 600mm, the area is potentially 36% larger. This increase is directly proportional to the power returning to the receiver, for equivalent tx power, antenna gain, range and rcs. Does that translate into an 8% benefit in range?
What radar mode are you operating in? What tradeoffs have you made between pulse duration, duty ratio, scan speed? What tradeoffs have you made in antenna setup for sidelobe performance, ECM, etc? How far off-axis is the target? Have you got a swashplate design, or a fixed forward-only array? How sensitive are your receivers, how much loss is built into the system? How much does the aircraft nose cone distort the signal? How effective are your signal processing algorithms? How much processing power did you build into the signal and data processors to carry out those algorithms? |
According to the Indian AF, MMRCA is a Mig-21 replacement. "the MRCA tender was floated with the idea of filling the gap between its future Light Combat Aircraft and its in-service. The IAF planned to replace the MiG-21 fleet with the indigenously-built HAL Tejas (LCA) aircraft. " So I think they are not doing an apples for apples but re configuring for the current scenario where Mig 21 - 27 and the Jags will be retiring to be replaced by a single aircraft to carry that load. |
Originally Posted by pr00ne
According to the Indian AF, MMRCA is a Mig-21 replacement
Originally Posted by Wannabe Flyer
So I think they are not doing an apples for apples but re configuring for the current scenario where Mig 21 - 27 and the Jags will be retiring to be replaced by a single aircraft to carry that load.
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What radar mode are you operating in? What tradeoffs have you made between pulse duration, duty ratio, scan speed? What tradeoffs have you made in antenna setup for sidelobe performance, ECM, etc? How far off-axis is the target? Have you got a swashplate design, or a fixed forward-only array? How sensitive are your receivers, how much loss is built into the system? How much does the aircraft nose cone distort the signal? How effective are your signal processing algorithms? How much processing power did you build into the signal and data processors to carry out those algorithms? It's like the engine size in a car at the end of the day. Yes a 1.6 turbo 16v can be more powerful than a 2.0 n/a 8v car. But implement turbocharging & a 16v head on the 2.0 and it will always have the potential to deliver more power. The same applies to the radar aperture. I'd be interested to know if my 8% assumed basic benefit from the radar range equation for rafale vs typhoon is sound. I think it is a valid point as while you can play with/upgrade signal processing etc. it is, for practically purposes, impossible to alter the diameter of the airframe at the radome. Rafale will only have 600mm for 30+ years. |
Ok so basically what you are saying is that in reality the Rafale radar is better then.
The "my car has a bigger engine but yours is more powerful" example speaks for itself. |
Originally Posted by KAG
Ok so basically what you are saying is that in reality the Rafale radar is better then"
For instance; I would be very surprised if Rafale outperforms Typhoon when the aircraft "definitely isn't pointing at the target" (avoiding all mention of actual angles), because that's a known limitation of fixed single-array AESA. Typhoon currently has a mechanically-scanned antenna that can point its full effort in a single direction, and the trialled Typhoon AESA has a mounting that lets it angle the array to mitigate this. Having worked on the design side of Blue Vixen and CAPTOR (ECR-90 as it was then), I was rather proud of what we produced; but that was over a decade ago, and I genuinely have no idea how well or badly RBE2 performs compared to CAPTOR. I also haven't got a clue about how well RBE2-AA works, or how it compares to CAESAR. If the CAESAR production contract goes ahead, I would be surprised if the T/R element technology isn't as least as good as (if not better than) the RBE2-AA T/R elements, simply due to Moore's law - if you go to design freeze two years later, you get two years improvements in process technology. |
I agree with all gravelbelly says - I had a feeling that there was some crewe toll experience given the Edinburgh location.
My point was only a simple one about size, though its true that many other factors apply. That said an 8% benefit/improvement in any aspect of radar performance is not something to be sniffed at. I also don't know whether the rafale pesa is better / worse than ecr90, though I recall the rumour being ecr90 as fundamentally an excellent mech radar based on sound proven technology, whereas the rbe was a bit of a technology deadend (in a similar way to fmicw foxhunter ai24). Rbe pesa looks sexy in the brochures but it doesn't offer the true advantages of an aesa radar. This is potentially academic as I assume the Indians would get the aesa rafale, not the pesa one, which you can assume is a much better system (if they've mastered the tech). Also worth noting that there maybe a telling reason why rafale is getting the aesa upgrade & typhoon hasn't yet - i.e. the pesa rafale needed the upgrade a lot more than an ecr90 typhoon and as such was easier to justify. Just speculation of course. |
Originally Posted by JFZ90
Also worth noting that there maybe a telling reason why rafale is getting the aesa upgrade & typhoon hasn't yet - i.e. the pesa rafale needed the upgrade a lot more than an ecr90 typhoon and as such was easier to justify. Just speculation of course.
Or the French were able to decide to do the upgrade... whereas the ECR90 upgrade is mired in a multi-national committee, amidst arguing over production shares, cost estimates, desired performance thresholds, and who still owes who for lunch and that bet over last week's FIFA matches! Or a dozen other possible reasons that have little or nothing to do with which systems performs better in which areas... I strongly suspect that each systems has areas where it is superior and ones in which it is inferior! Unless you can get hold of the classified performance documents for both current systems, as well as the classified documents on the new systems, including costings and so on, all you can give is biased personal-preference wild guesses! |
GK you maybe right - I'm just speculating on other possibilities - I think it is too easily assumed that the reasons are some of the common ones oft repeated.
Have the US ever fielded a pesa ai radar? Was it any good? |
IAF fighter deal: Rafale much cheaper than Typhoon; govt rules out review - The Times of India
22% higher cost!!! Is it possible |
The more time does elapse, the more it becomes difficult for the anglo-saxon world to swallow it.
One of the most common ideas of them, written widespread over the media and the net, is that "so far Rafale has been unable to attract a single export order" So what ? Now they say "Typhoon has biggest margin for improvement" - in other words, it's not finished, a lot of key capabilities are missing, so yes all that could be done one day... at a significant cost, with no guarantee that it could ever work or be finished (look at Nimrod Mk2 or Nimrod "AWACS") and for that development to take place, agreements would have to be found with the other consortium nations... and those countries are just so lagging behind, no longer wanting to commit a single penny or even to finish their current orders... And now the British PM says "we will make the Typhoon less expensive" ... which is in total contradiction with the above story about future required development, isn't it ? Stop saying Typhoon can drop a laser-guided bomb : it can... like any fighter, even a Hunter could do that, with a smarter aircraft illuminating the target (remember Buccaneers and Tornadoes in the first Gulf War) And what about recce pods, cruise missiles, anti-ship missiles, carrier landing capability for the dedicated version ??? and for this last point, don't say the future Indian carrier will not need it : that ship is far from being finished, and design is not frozen... Answering all those questions does give you the keys of the deal. Yes, it was a very important deal for both aircraft, a question of survival, and one had to lose... All that is a little bit reminiscent of the last Rugby Cup : how could it be, really, that France did beat Wales, England, and finished close to beating NZ ? yes, how could it be ? Allez la France. http://s2.lemde.fr/image/2012/01/31/...6126220717.jpg |
"France did beat Wales, England, and finished close to beating NZ ? yes, how could it be ?"
Only one possible answer - they must have cheated!!!! |
To all of us still dreaming :
Given all this, (Indian) MoD has ruled out the possibility of "any comeback" by Typhoon despite carping by the four nations (UK, Germany, Spain and Italy) backing it That's from "The Times of India" of today. IAF fighter deal: Rafale much cheaper than Typhoon; govt rules out review - The Times of India |
Well, perhaps it's not all bad news - surely there's a gap now in competing for the supply of all the maintenance and support for the Rafale?
We (Brits) have a few decent maintenance companies that are quite capable of taking on a relatively small fleet of 120+ jets that may not fly 500 hours per year. That contract itself could generate about 500-600 jobs plus the Indian and french percentages...and over at least 5-10 years...? |
"Secret Defense", a blog by the french journalist J-D Merchet (defense specialist), announce that India will share some of its MMRCA evaluation experience with Brazil.
The source is this article of the Times of India. On the same billet, the blog links a leaked flight evaluation report (in english) by the Swiss Air Force (indeed, the billet is titled "In Switzerland, the military believe that the Gripen is unable to fulfill the tasks set") As I feel it may enlighten some of the India's stories, I report it here (haven't found any more relevant topic on the swiss competition). Abstract: Among the three NFA candidates, the Rafale was the aircraft which demonstrated the best effectiveness and suitability in the accomplishment of all types of Air-to-Air missions, Recce and Strike missions. In addition, the Rafale made the best impression to the pilots. The strong points of the Rafale were the quality of its sensors such as the PESA radar, the Frontal Optronics and the EW suite SPECTRA. The good data fusion of all its sensors allowed to provide to the pilot a very good Situational Awareness. A new concept to display all mission data has been implemented. The Recce Pod demonstrated also outstanding performances. The actual weak point of the Rafale was the lack of Helmet Mounted Sight System. The Rafale has been rated satisfactory in the accomplishment of all types of Air-to-Air, Recce and Strike missions with some enhancing characteristics in several domains. The Rafale obtained the 1st rank in the evaluation of the effectiveness. The Eurofighter was able to fulfill all Mission Essential Tasks required by Air-to-Air missions. Hence, in the Air-to-Air domain, there were several deficiences that prevented a good execution of some mission essential tasks. The a/c performances (super cruise at Mach 1.4) were among the strong points of the Eurofighter. The sensor data fusion and the EW suite performances can be mentionned among the weak points. The Eurofighter was rated satisfactory for Air Policing missions and satisfactory with comments in the accomplishment of DCA and Escort missions. The Eurofighter could be engaged in Recce and Strike missions, nevertheless there were also several limiting factors affecting the overall mission success. Range and systems reliability were the main limiting factors of the Eurofighter. The RecceLite Pod provided only basic solutions for Recce Tasks. For Strike missions, the Eurofighter was not able to engage multiple targets in one pass (multiple DMPI). Despite the mentioned limitations, the capabilities of the Eurofighter to fulfill Recce and Strike missions were rated as unsatisfactory. The Eurofighter obtained the 2nd rank in the evaluation of the effectiveness. Although the Gripen could be engaged in all type of Air-to-Air, Recce or Strike missions, there were several limiting factord affecting the overall mission success. Given by its design, the endurance, aircraft performances and aircraft weapon load were among the main limiting factors of the Gripen. For Recce missions, the RecceLite Pod was also used by the Gripen. Multiple targets were not able to be engaged during Strike missions. There was no sensor data fusion between the Radar and EW suite. Among the strong points, the Gripen has three large screens to display Situational Awareness and mission data. The EW suite can be mentionned among the strong points of the Gripen. The Gripen has been rated unsatisfactory in the accomplishment for Air-to-Air and Strike missions. In the Recce domain the Gripen was assessed satisfactory with comments. The Gripen obtained the 3rd rank in the evaluation of the effectiveness. Report. |
Going back to the thread's origin, I would like to ask if someone knows why the us did not offer the F35 in the indian competition. Politics?
Thanks for your answers |
Not so much politics. F-35 was unqualified on grounds of inability to meet schedule, inability to perform in-country demonstrations, impracticality of necessary technology transfer, and no doubt many other reasons. (I'd love to see an F-35 attempt a take-off at Leh on a hot day, without reprising the old ZELL concept and strapping a 150K lb thrust solid booster to its a**e.)
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The report referenced by the french blog relates to trials conducted in 2008 and promised capabilities in 2015. Is it still correct and relevant?
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@ engineer(retard): I'm not aware of any "revolution" in the developpment roadmap of any of the 3 contenders, so basically I would say 'yes'.
Do you have other data making you think those results now are irrelevant (I can't see why they would be incorrect)? |
AZR stop being defensive, it was a reasonable question. I don't have an axe to grind about the selection, are you involved with any of the contenders?
Have any of the contenders had a change or capability upgrade in the last 4 years? Do any of those capability upgrades effect the conclusions of the Swiss report? Have they all delivered their roadmap capability in the last 4 years? What external dependencies are there to achieving their capability e.g funding? I can think of those questions off the top of my head without trying if I wanted to use old information to base a decision on today. |
Not so much politics. F-35 was unqualified on grounds of inability to meet schedule, inability to perform in-country demonstrations, impracticality of necessary technology transfer, and no doubt many other reasons. Other countries are already facing capabilities gaps while they are expecting the F35... |
Originally Posted by LeCrazyFrog
Other countries are already facing capabilities gaps while they are expecting the F35...
If you are from a lazy or peaceful place (follow my glance) you can have a capability gap, as you say. And you are even totally free to wait for something promised to be wonderful, not finished, but costly for sure. If you are from India - Israel - Turkey - France - UK - ... ? - you can't wait, period. You cannot afford a gap. If you are an airline, and you have to wait for the Boeing 787 to be delivered/finished, it's really not a big deal : you keep flying other aircraft which are doing the same job, you rent some others... now if you are an Air Force, the consequences of waitng for the proper aircraft could be a problem (once again, provided we speak from a country with some action overseas or at the borders) You say : the "mighty" F-35 .. ?.. why mighty ? because it's american, and by definition it has to be a great aircraft ? for the moments it seems to have its fair share of problems, and budgets overflows. Indians were very right in saying they were not interested - and they did explain why ! |
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