Thank you for all the data.What is the main problem for us ('public') is that we don't know real characteristics of those TRMs inside of the four centimetric X-band AESA.
Then what ? You can use that paper and do your own calculation. Especially that Radar Range Equation is widely known and all you need is some reasonable basic assumption.
14-18 Watt use that.
Just dumping articles and papers without actually draw meaningful information is kinda like spamming tbh.
Pulse Doppler radars remain the primary long range sensors used by fighter aircraft for BVR combat.Peak Power (Ppeak) [kW] is the maximum pulsed power the radar can emit.
So what we have ... 1526 TRM's in the main forward N036 AESA x 10W =15.26 kW + 2 SLAR N036B AESA with 358 TRM's each is 716 x 10W=7.16 kW ,total= 22.42 kW ?
I can't see a reason to add up the peak power output of three non-overlapping antennas.
The interesting comparison would be the ratio of power to the side arrays compared to front - basically only a quarter, so all things equal max detection range for these is similarly less.
Then what ? You can use that paper and do your own calculation. Especially that Radar Range Equation is widely known and all you need is some reasonable basic assumption.
14-18 Watt use that.
Just dumping articles and papers without actually draw meaningful information is kinda like spamming tbh.
In contrary, if I may, I will present two cases from the practice ,real life.
On March 1999 during Operation Allied Force, one YuAF MiG-29B pilot, detected and tracked low-flying cruise missile (it was BGM-109 Tomahawk) at a distance of 30km in the front hemisphere. If I am right ,BGM-109 with metallic skin has about 0.3 sqm of frontal RCS in centimetric X-band ( angle aspect +/-15°) ? He flew at about 4000m ,cruise missile at about 100m AGL. Radar N019EB of his MiG-29B could not work in the lock-on mode. As we know,N019EB was downgraded export version of the N019 for non-WP countries.Radar N019 'Rubin' possess TWT with about 1kW of average power in the HPRF mode and with max output pulse power of about 8kW in HPRF mode. Due to unfinished overhaul during 1996/97, the YuAF MiG-29Bs had mostly malfunctioning radars with significantly weakened TWT's.
On May 2013, during the exercise over Pemboi range in Syberia ,one MiG-31DZ locked-on and engage incoming low-flying cruise missile Kh-55 launched from the Tu-95MS with AAM type R-33 from a distance of 90km. Detection/tracking distance was certainly bigger. N007 Zaslon's main TWT has 2.5kW of average power in HPRF mode and has max output pulse power of 10kW in HPRF mode. PRF in the HPRF mode for both is 180-200kHz.
If we talk about N036 ( frontal AESA) maybe only that we have are some sequences made in 2018 in Sukhoi sim-room. From 21:42 we can see 4 aircraft tracked in PPS mode ( front hemipshere) with a current distance to aircraft scale.Numbers besides scale are : 40,80,120,160 and 200 km.Suppose that it was half of the main scale ranging from 0-400km (0-50-100-150-200-250-300-350-400 , like for N035 Irbis).
Any radar design regardless origins of country start with Radar range equation. whether you like it or not. Differences with practical experience lies in the manufacturing and then environment. Good book exist and this one below is actually translated from Russia on the subject.
If we talk about N036 ( frontal AESA) maybe only that we have are some sequences made in 2018 in Sukhoi sim-room. From 21:42 we can see 4 aircraft tracked in PPS mode ( front hemipshere) with a current distance to aircraft scale.Numbers besides scale are : 40,80,120,160 and 200 km.Suppose that it was half of the main scale ranging from 0-400km (0-50-100-150-200-250-300-350-400 , like for N035 Irbis).
In contrary, if I may, I will present two cases from the practice ,real life.
On March 1999 during Operation Allied Force, one YuAF MiG-29B pilot, detected and tracked low-flying cruise missile (it was BGM-109 Tomahawk) at a distance of 30km in the front hemisphere. If I am right ,BGM-109 with metallic skin has about 0.3 sqm of frontal RCS in centimetric X-band ( angle aspect +/-15°) ? He flew at about 4000m ,cruise missile at about 100m AGL. Radar N019EB of his MiG-29B could not work in the lock-on mode. As we know,N019EB was downgraded export version of the N019 for non-WP countries.Radar N019 'Rubin' possess TWT with about 1kW of average power in the HPRF mode and with max output pulse power of about 8kW in HPRF mode. Due to unfinished overhaul during 1996/97, the YuAF MiG-29Bs had mostly malfunctioning radars with significantly weakened TWT's.
On May 2013, during the exercise over Pemboi range in Syberia ,one MiG-31DZ locked-on and engage incoming low-flying cruise missile Kh-55 launched from the Tu-95MS with AAM type R-33 from a distance of 90km. Detection/tracking distance was certainly bigger. N007 Zaslon's main TWT has 2.5kW of average power in HPRF mode and has max output pulse power of 10kW in HPRF mode. PRF in the HPRF mode for both is 180-200kHz.
Any radar design regardless origins of country start with Radar range equation. whether you like it or not. Differences with practical experience lies in the manufacturing and then environment. Good book exist and this one below is actually translated from Russia on the subject.
Of course,as mentioned before ,first comes theory,papyrology,math. modelling,comp. simulation etc... Thanks for the recommended book.
160 km exactly ,arrow show that current distance to aircraft/target ,yes.
No of course but the point of the story is that we have sometimes completely different data ,values etc in the practice then what we can read from some sources.
In the meantime....
Yury Trutnev (as Deputy Prime Minister of Russia and Presidential Envoy to the Far Eastern Federal District) was in KnAAZ about month ago. We can see one almost finished new Su-57.Maybe it is already finished and ready for the delivery...
We mentioned and wrote some comments about that decimetric L-band AESA radars N036L.Here we can see them during serial production of the Su-57's in the KnAAZ.
In the meantime I've finally found some transl. of those pages that we have from the Russian doc. If I may, I will put it them here.Page 1 is already translated .
''2. Goals, objectives and initial data for the work 2.1 Goal of the work Development of technology, algorithms and hardware for assessing and adjusting the amplitude-phase characteristics and directional diagrams of the PESA and AESA and their elements during the creation and serial production of the radar. 2.2 Objectives of work In the course of the R&D, the following tasks should be solved: - a basic technology for creating a linear phased array (PESA) / AESA of the L-band and a general scheme for its construction, ensuring the implementation of the modes of operation of the IFF and radar; - the basic technologies for the manufacture of key devices AESA-L have been developed:a block of emitters, a receiving-transmitting amplifier module ( TRM or PPUM), a distribution and phasing device (URF) and a pattern generator ( radar beam ) ; - prototypes of input devices for linear PESA / AESA L-band were developed and manufactured in accordance with the general construction scheme; - programs and methods were developed, and prototypes of input devices of linear PESA / AESA L-band were adjusted and tested; -tests of the created technology, algorithms and hardware for assessing and adjusting the amplitude-phase characteristics and directional patterns ( radiation patterns -radar beams) of the PESA and AESA and their elements were carried out. - a set of letter complect ( Liter on russian for adjusting working frequencies or radiation patterns ) type "O" was developed for prototypes of the L-band PESA / AESA input devices and test models for the developed technologies; - the conclusion of the consumer enterprise was received on the level of parameters provided by the developed technology; - proposals were given for the manufacturer, the procedure and terms for mastering the product. 2.3 Initial data .As a result of the R&D, basic technologies should be created for the production of key input devices of the L-band PESA / AESA, taking into account the possibility of placement on the T-50 , consisting of: specified radiation characteristics when working with a specialized radio-transparent fairing; - the distribution and phasing device should be based on the microwave hybrid-integral Circuits for SHF ( Super High Frequency ) with hinged mounting of LF ( Low Frequency) control components and the use of a microstrip transmission line; - the radiation pattern ( radar beam ) former should be made on the basis of a symmetrical strip line, using modern materials such as Rodgers ( Rodgers materials ) ; - TRM should be made four-channel, with power amplifiers (PA) for transmission and reception in each of them. All PAs are based on microwave /Monolithic Integrated Circuits for SHF with the implementation of low duty cycle (Q = 20) modes, provided when using liquid cooling.''
''3. The electrical circuit of the TRM must ensure interface with the mains of control and information signals. Stage 3. Content of work 3.1 Stages of work and their results Content of work of stage Result 1 Draft and technical design for technologies, algorithms and hardware for assessing and adjusting the amplitude-phase characteristics and directional diagrams of the phased array/PESA and AESA and their elements during the creation and serial production of the radar ... Development of the basic technology for constructing PESA / AESA L-band. Development of basic technologies for the manufacture of key PESA / AESA devices for the emitter unit, TRM, URF ( distribution and phasing devices) , pattern generator. Manufacturing of models of L-band AESA input devices. (what is presented) Explanatory note to the draft technical design on technologies, algorithms and hardware for assessing and adjusting the amplitude-phase characteristics and directional patterns of the phased array/PESA and AESA and their elements during the creation and serial production of the radar ..Models of the input devices of the phased array / AESA L-band : -- block of emitters; - transceiver amplifier module; - distribution and phasing device; - radiation pattern /beam shaper. Terms of implementation Terms of performance of stages of work are set at the conclusion of a state contract 2 Development of design documentation for prototypes of input devices of the L-band phased array -PESA/AESA and techn. doc. for the developed technologies. Development of programs and test methods for models of input devices for linear PESA / AESA L-band. Testing of models of input devices of L-band phased array-PESA / AESA. Design documentation for prototypes of L-band phased array / AFAR input devices and technical documentation for developed technologies. The program and methods of testing the models of the input devices of the L-band PESA / AESA. Test reports of the models of the incoming The deadlines for the stages of work are established at the conclusion of the state contract.''
''4. Stage Content of stage work Result 3 Manufacturing of prototypes of L-band phased array -PESA/ AESA input devices. Conducting preliminary tests of prototypes of the input devices of the L-band PESA / AESA . Adjustment of design documentation and technical documentation based on PI results. Assignment of the letter "O" ( working frequencies) to RKD, TD ( static and flight test models ) Methodology for predicting the characteristics of L-band PESA / AESA based on the test results of prototypes of input devices. (what is shown) devices. Acts and protocols of PI of prototypes of input phased array / PESA and AESA L-band devices. Sets of test models letter "O" for prototypes of the input devices PESA / AESA L and TD of the letter "O" for the developed technologies. Scientific and technical report on ROC. Terms of performance Terms of performance of stages of work are established when concluding a state contract Note: 1. The content of stages of work is specified according to the results of a competition when concluding a state contract. 2. The list of documents developed during the organization and implementation of R&D (R&D stages) are presented in accordance with the requirements of GOST RV.( GOST RV 15.002-2003 “System of product development and launching into production. Military equipment. Quality Management System. General Requirements "is a state military standard of the Russian Federation that sets requirements for a quality management system. ) 1. Sets of CD letter "O" for prototypes of input devices L-band PESA / AESA and TD letter "O" for the developed technologies. 2. Models of the incoming PESA / AESA L-band devices. 3. Prototypes of L-band phased array PESA / AESA input devices including: - block of emitters; - transceiver amplifier module ( TRM or PPUM);''
''6. - Distribution and phasing device (URF) - DN shaper ( radar beam ) . 4.2 Requirements for the designation of the L-rband phased array PESA / AESA as part of the developed prototypes of input devices is intended for directional transmission of radar signals and signals of the state identification system in the frequency range GHz (f1 subband) and GHz (f2 subband), respectively, as well as for receiving signals in the frequency band GHz Linear L-band PESA / AESA as part of the developed prototypes of input devices should provide one-dimensional electronic beam control in all specified frequency ranges in the azimuthal angular sector of the L-band PESA / AESA should form the following radar beam pattern. When operating in the f1 sub-band: - total DN ( radiation pattern) during transmission and reception; - differential DN during reception (simultaneously with the total); - compensatory beam when working at the reception (simultaneously with the total);When operating in the f2 sub-band: - total DP during transmission and reception; - compensatory DN during transmission; - compensatory DN when working at the reception (simultaneously with the total); When working on transmission, it should be possible to form a total DN for two operating modes of the maximum power mode and optimal DN. Scanning sector of AESA L -band in the azimuthal plane is +/-55°. The appearance of diffraction lobes when scanning in a given sector is not allowed. The polarization of the field of the emitted and received signals is vertical. The potential for transmitting in the maximum power mode should be at least ( no less then ) 360X n2 Watts, where n is the number of emitters ( 12 pour one antenna ) . The potential for transmitting in the optimal DN ( radar beam ) mode should be at least 250X n2 Watts , where n is the number of emitters. The gain in the receive mode must be at least 7X n2, where n is the number of emitters. The width of the radiation pattern/ beam in the azimuthal plane at a level of minus 3 dB when operating in the f1 sub-band should be.''
''7. When operating in transmission : - maximum power mode, degrees - (130+ - 3) / N / cosΘ; - optimal DN mode, deg - (125+ - 3) / N / cosΘ where Θ is the angle of deviation of the main maximum of the DN relative to the normal to the antenna, N is the number of emitters . When operating on receiving , deg: (135+ - 3) / N / cosΘ, where Θ is the deflection angle the main maximum of the pattern relative to the normal to the antenna, N number of emitters; optimal DN mode, deg - (108+ - 2) / N / cosΘ; where Θ is the angle of deviation of the main maximum of the antenna pattern relative to the normal to the antenna, N is the number of emitters When operating at reception, degrees: (120+ - 2) / N / cosΘ, where Θ is the angle of deviation of the main maximum of the pattern relative to the normal to the antenna, N is the number of emitters. Width of the pattern in the elevation plane at the level of minus 3 dB should be 70-90 degrees in all modes. When operating in the f1 subband, the maximum side lobe of the total DN should be in the + - 30 / cosθ zone relative to the beam axis.The level of the maximum side lobe at the axial position of the beam should not be higher than minus 17 dB in the transmission mode and minus 22 dB in the receiving mode. - The overlap ratio of the side lobes of the total DP of the differential DP when transmitting in the f2 subband must be at least: For the maximum range mode: - in the scanning sector to; + - 30° -0.68 - in the scanning sector over; + - 25° -0.62. For the optimal DN mode: in the scanning sector up to; + - 25° -0.78 - in the scanning sector above the + - 25° -0.70 . Coefficient of overlapping of the side lobes of the total DN of the differential DN when working for receiving in the f2 subband must be at least: - in the scanning sector to; + - 25° -0.86 - in the scanning sector above the + - 25° -0.80 . Depth of the difference DN minimum relative to the total DN maximum should be at least 25 dB . The steepness of the synthesized direction finding characteristic (DF) should be at least 15cosΘ% / deg. Beam positioning error no more than:''
''8. when working in the sub-range ∆f1: 0.8 ° / cosΘ; - when working in the sub-range ∆f2: 0.6 ° / cosΘ The installation time of the L-band PESA / AESA beam in any angular position should not exceed 10 μs. The DN inversion time should not exceed 0.4 μs. The return to the initial antenna pattern should be made no more than 0.4 μs after the control signal is applied. Requirements for the characteristics of the emitter unit . The standing wave ratio level or VSWR at the emitter input must not exceed the 1.8 . Emitters must have linear polarization orthogonal to the AESA plane . The mass of the emitter unit must not exceed 0.87 kg . Requirements for characteristics of PPUM-TRM PPUM should have 4/5 transmitting / receiving channels . The output pulse power per channel should be at least 400 W. The maximum deviation of the output power value should be no more than 50 W. Parameters of the amplified pulse: - duration, 1-100μs; - duty cycle;20-200Requirements for the shape of the output pulse in the f1 subband : - duration of the rise and fall, no more, 0.1μs: narrowing of the envelope relative to the input pulse, no more,0.1 μs: front delay relative to the input pulse, no more, 0.1 μs . - bevel of the top of the envelope, no more, 2% Requirements for the shape of the output pulse in the f2 subband: - duration of the leading edge, no more, 0.15μs: - duration of the fall, no more than, 0.25μs: The noise figure of the receiving channel should not exceed 3dB , The efficiency of the TRM must be at least 20%.Power consumption of TRM should not exceed 500W , The mass of the TRM should not exceed 4.35 kg Requirements for distribution and phasing device , must be four-channel.''
''9. Distribution and phasing device (URF) should form a constant amplitude distribution at the outputs in the case of an active PA/AESA and uneven according to a special law in the case of a passive PA/PESA . The bit width of the phase shifter is not less than 5. The standard deviation of the phase setting at the URF outputs should not exceed 5° , URF must have an efficiency of at least 60%. Power consumption should not exceed 19 W. The mass of the URF should not exceed 0.42 kg. Requirements for the DN/beam generator The VSWR level at the inputs and outputs of the DN generator should not exceed 1.3.. The transmission coefficient from the input to the outputs of the antenna pattern shaper should be 3.2 ± 0.3 dB. The decoupling between the outputs of the antenna pattern must be at least 27 dB .. The DN mass former should not exceed 0.13 kg.Increased temperature of the environment for prototypes of the input devices of the PESA / AESA L-band, placed in the front part of the deflected toe of the wing: -working, ° С - plus 75 °; -working increased short-term, ° С - plus 135 °; -limiting, ° С - plus 140 ° . Reliability requirements. Criteria for failure of prototypes of input PESA / AESA L-band devices should be determined at the development stage .So that's it ,pages 10,11 and 12 give some info that are not more interesting ( no techn. data ) .''
If you move the nozzles symmetrically, you can adjust the trim drag. However, the canted orientation will generate wasted side forces that cancel out, so a bigger thrust penalty for trim drag reduction. Don’t know if it would be a net gain.
Yeah when you listen to the creators dogfighting is a serious aspect to TVC but the two other big ones talked of are short takeoff performance and greater safety margins. These are often glossed over.
I'd say they are even more important. Modern planes rarely, go dogfighting. But improved safety and better take-off influencing every flight and reduce number of accidents.
I think they are forced to stick with the canted nozzles. The airframe was designed to handle canted nozzles. It will flush with the rest of the aircraft better and get more rcs reduciton with uncanted nozzles .The loss of yaw can kinda be compensated with all moving v tail and "splitting the throttles". This sort of feels like an afterthought to me.
I'd say they are even more important. Modern planes rarely, go dogfighting. But improved safety and better take-off influencing every flight and reduce number of accidents.
Well the first serial su-57 ,a few Y/F-22s and two 737 max have crashes related to FCS. The Japanese claimed the x-2 has a giant beetle RCS (because of US approval). It has exposed tvc metal paddles and the intakes are not planform aligned so it is just PR. The main purpose should be testing their own version of "Self Repairing Flight Control Capability" which seemed to be first researched by the F-15 ACTIVE.
The Su-27M was a project from the 80s to maximize the dogfight of the flanker so it got the canted TVC.Su-35 adopted it and eventually Su-57. Su-57 is not a body kit flanker of course but is still a "victim" of it. The weapons bay is derived from the Su-47 and they have to make do what they have.Weapons bay/pylon problems is not unique to Russia. KF-21 will have weapons bay some years later and the only "benefit" of the canted pylons of the super hornet is additonal drag.Using the weapons bay of Su-47 is quite reasonable.
The Su-27M was a project from the 80s to maximize the dogfight of the flanker so it got the canted TVC.Su-35 adopted it and eventually Su-57. Su-57 is not a body kit flanker of course but is still a "victim" of it. The weapons bay is derived from the Su-47 and they have to make do what they have.Weapons bay/pylon problems is not unique to Russia. KF-21 will have weapons bay some years later and the only "benefit" of the canted pylons of the super hornet is additonal drag.Using the weapons bay of Su-47 is quite reasonable.
Only one prototype of the Su-27M got TVC and that was T-10M-11 number 711, widely known as Su-37. After that ,same solution for the TVC was applied on Su-30MKA,MKI,MKM ( AL-31FP) ,then Su-35S ( AL-41F-1S) and Su-30SM/SM2 (AL-31FP/AL-41F-1S).
Of course ,AL-41F-1 and newer AL-51F for the Su-57 have that same solution.
When we talk about that Su-47 called Berkut ( S-37), it was technological demonstrator for the stealth technologies and for the testing of the composite materials especially composites as structural materials for the wings.
Citation :
''In 2006-2007, after the weapon compartment was modernized, the aircraft was involved in the program to create the T-50 fighter project (later Su-57). The goal was to test the compartment doors and internal equipment for operability under real flight conditions. The information was actively used in the final stages of creating the weapon compartments of the T-50 fighter.''
''Work on the wing for the Berkut subsequently made it possible to use composites from Obninsk in the creation of the fifth-generation Su-57 fighter and the MS-21 airliner.''
can someone explain why canted nozzles are not as good as vertical nozzles? Why do they create drag I never really understood that discussion? If I remember correctly the su-35/37 it was numbered 117 and it could move its nozzles up and down but not canted. Then when the su-30 was introduced that’s when the v pattern TVC was used.
What’s good about the canted nozzles is that when moved asymmetrically, they can generate yaw and rolling moments that can help maneuvering those planes without the complication of full 3D vectoring.
The downside is when they are actuated symmetrically for pitch vectoring, more thrust is wasted generating side loads that are cancelled out.
Plus, the new Su-57 2D flat nozzle just look wrong, and are unlikely to make a large contribution to overall stealth of the aircraft due to adding additional flat surfaces not aligned with the existing airframe edge alignment. It remains to be seen if there will be any significant improvement in observability inside the AB cavity.
What’s good about the canted nozzles is that when moved asymmetrically, they can generate yaw and rolling moments that can help maneuvering those planes without the complication of full 3D vectoring.
The downside is when they are actuated symmetrically for pitch vectoring, more thrust is wasted generating side loads that are cancelled out.
Plus, the new Su-57 2D flat nozzle just look wrong, and are unlikely to make a large contribution to overall stealth of the aircraft due to adding additional flat surfaces not aligned with the existing airframe edge alignment. It remains to be seen if there will be any significant improvement in observability inside the AB cavity.
The flattened exhaust nozzle installed at an angle is planned to reduce the signature of advanced versions of the Su-57. The novel flattened exhaust nozzle is planned to reduce the radar signature of advanced versions of the Su-57 Felon fighter.
www.twz.com
There is AB blocker RCS simulation in the comments section
What’s good about the canted nozzles is that when moved asymmetrically, they can generate yaw and rolling moments that can help maneuvering those planes without the complication of full 3D vectoring.
The downside is when they are actuated symmetrically for pitch vectoring, more thrust is wasted generating side loads that are cancelled out.
Plus, the new Su-57 2D flat nozzle just look wrong, and are unlikely to make a large contribution to overall stealth of the aircraft due to adding additional flat surfaces not aligned with the existing airframe edge alignment. It remains to be seen if there will be any significant improvement in observability inside the AB cavity.
Apart from what was M7 analysed ,Mikhail Strelets said this :
‘'In essence, the flat nozzle complements the existing aerodynamic controls by allowing the creation of moments in three planes and thus pitch, roll and yaw control. And since the nozzle installation angle is preserved with axisymmetric, all the possibilities of super manoeuvring the aircraft are also preserved,’ explained Mikhail Strelets.''
''По словам главного конструктора, плоское сопло также обеспечивает малую заметность в радиолокационном диапазоне за счет характерной формы и может использоваться в широком диапазоне высот и скоростей полета самолета. Оно позволяет создавать управляющие моменты в трех плоскостях, сохраняя все возможности по сверхманевренности самолета.''
What’s good about the canted nozzles is that when moved asymmetrically, they can generate yaw and rolling moments that can help maneuvering those planes without the complication of full 3D vectoring.
The downside is when they are actuated symmetrically for pitch vectoring, more thrust is wasted generating side loads that are cancelled out.
Plus, the new Su-57 2D flat nozzle just look wrong, and are unlikely to make a large contribution to overall stealth of the aircraft due to adding additional flat surfaces not aligned with the existing airframe edge alignment. It remains to be seen if there will be any significant improvement in observability inside the AB cavity.
OK then ,now let us see what can do the '3D-nozzles' of the AL-41F-1S (also of AL-31FP and AL-41F1/-51F) .
On the upper left pic both nozzles (gas stream) are directed upwards, on the upper right pic, left nozzle is directed upwards,right is directed downwards.On the lower left pic we can see the vice-versa situation.
All of this can be done with that new flat nozzle.That's why this new flat nozzle is placed in this angled position.
So on PW F119 we have the flat nozzles that can be directed only straight upwards and downwards.This new flat nozzle as we can see can be directed upwards/downwards but with a beveled angle as in the mentioned engines.
In fact, that was a candidate for the second stage engine ''Izdeliye 30'' called 'Yeniseisk-B'.
Some info from 2010,source was VPK :
''Условиями конкурса на разработку двигателя второго этапа для ПАК ФА, по словам Юрия Елисеева, предусматривалось конструирование двух прототипов: "Енисейск-А" - "Сатурну" и "Енисейск-Б" - "Салюту". Первый этап состязания, предполагавший создание отдельных деталей, завершился в ноябре 2008 года; второй, в ходе которого участники должны были представить демонстраторы узлов, финишировал в июне 2009-го. "Что касается "Салюта", - заявил гендиректор этого предприятия, - то имеется заключение комиссии, состоящей из представителей Минобороны, ЦИАМ и ЦНИИ-30 МО, гласящее, что работа выполнена в полном объеме на уровне не ниже мирового, результаты рекомендуются для использования при проектировании двигателя пятого поколения. Что касается "Сатурна", то им, насколько я знаю, второй этап пока не выполнен". К третьему этапу, объявление которого откладывается с третьего квартала прошлого года, в КБ "Салюта" создан аванпроект двигателя пятого поколения, который согласно заключению соответствует техническому заданию.
Как заявил Юрий Елисеев, "у меня никогда не было сомнений, что двигатель пятого поколения может быть создан только совместными усилиями. Финансирование должно идти через ОДК. ''
''According to Yuri Eliseev, the conditions of the competition for the development of the second stage engine for the PAK FA included the construction of two prototypes: "Yeniseisk-A" for "Saturn" and "Yeniseisk-B" for "Salyut". The first stage of the competition, which involved the creation of individual parts, was completed in November 2008; second, in which participants had to present demonstrators of components, finished in June 2009.
"As for Salyut," said the general director of this enterprise, "there is a conclusion from a commission consisting of representatives of the Ministry of Defense, TsIAM and TsNII-30 MO, stating that the work has been completed in full at a level no lower than the world level, the results are recommended for use in the design of a fifth-generation engine.
As for Saturn, as far as I know, they have not yet completed the second stage." For the third stage, the announcement of which has been postponed since the third quarter of last year, the Salyut Design Bureau has created a preliminary design for a fifth-generation engine, which, according to the conclusion, corresponds to the technical specifications.
As Yuri Eliseev stated, "I never had any doubts that the fifth generation engine can only be created through joint efforts. Financing should go through UEC.''
So educate him instead of asking rhetorical questions. What is “RCS treatment”? The science says RCS can only be reduced, nothing can 100% be ‘treated’ in order to completely illuminate RCS. Any discontinuity, gap or seam creates interference with electromagnetic energy. Ideally designers want zero discontinuity with a surface that is perfectly smooth. However, in the real world that is not possible due to flight control surfaces, assess panels, auxiliary ports, bays, ect. There is no such concept of being invisible to radar, the best designers can do incorporate techniques such as faceting, edge alignment, RAM, ect in order to reduce the RCS. At certain distances and aspect angles some aircraft may be more or less invisible to certain radars operating in certain frequencies but once an aircraft gets closer to the source of illumination and the frequency and aspect angles are ideal then the aircraft may be visible.
There are no such thing as gaps or seems that are stealth, that is a contradiction. The best engineers can do is redirect the RCS away or try to mask it by using RAM or trying to shield it behind other structures such as vertical stabilizers. Everything is a design compromise, the YF-22 had the TVC engines and horizontal stabilizers but payed a penalty in stealth compared to the YF-23.
Yes the F-22 has serrated seams around the engine to minimize RCS and the effects of edge diffraction but it will never eliminate it completely and from every aspect angle. Moreover there are 90 degree corner reflectors. The reason the YF-23 had a lower RCS compared to the YF-22 was precisely because it omitted the horizontal stabilizers to eliminate those additional corner reflectors and simplified the engines. There is nearly no seams anywhere on the WF-23 as it’s a fixed engine recessed into the rear fuselage.
...rear array(for 360 coverage and more array estate than dedicated NGJs), side L arrays(~240 coverage), spherical optics in two bands(UV, mwIR), dual-band frontal irst(mw/lwir), spherical DIRCM, full integration (system design, data fusion, cross use for different subsystems) for everything above, active countermeasures as designed, actual flight and stol performance worthy of its generation, comprehendive weapon suite working earlier than 10 years after IOC, and LO. Helmet was also always there, too, the difference is you now got to see it in production form. As are other normal generation features no one bothers to mention.
A lot of things you've missed. All of them designed in since 2001, well known for more than a decade. All much more important for the aircraft than flat nozzles.
It makes your final assessment questionable, as you were clearly gauging some other aircraft.
Absolute majority of people coming to this thread with their opinions - don't even have wiki level knowledge on the subject(or do, and come somewhat overenthusiastic). Then it takes several pages of amazing discoveries.
It's one thing when someone comes to ask, but for judgements normally it's polite to at least make some research first?
What’s good about the canted nozzles is that when moved asymmetrically, they can generate yaw and rolling moments that can help maneuvering those planes without the complication of full 3D vectoring.
The downside is when they are actuated symmetrically for pitch vectoring, more thrust is wasted generating side loads that are cancelled out.
Plus, the new Su-57 2D flat nozzle just look wrong, and are unlikely to make a large contribution to overall stealth of the aircraft due to adding additional flat surfaces not aligned with the existing airframe edge alignment. It remains to be seen if there will be any significant improvement in observability inside the AB cavity.
So flat smooth nozzles with less seams and discontinuities do almost nothing for RCS compared to round nozzles that have multiple chambers and dozens moving parts, bolts, gaps and no edge alignment?
Even if we are talking about the round “stealth” nozzles they still have the variable nozzle flaps that create some corner reflectors and at full deflection there are gaps between the flaps…there is simply no way that something like that has the same or lower RCS compared to a flat nozzle that emits all those flaps and gaps and moving parts. Moreover, the flat nozzles provide superior IR signature. With flat canted nozzles the engineers also eliminated the phenomenon of ‘creeping waves’ and also eliminated a rough cylinder and replaced it with a mostly smooth canted surface. The RCS improvement should be significant.
If you move the nozzles symmetrically, you can adjust the trim drag. However, the canted orientation will generate wasted side forces that cancel out, so a bigger thrust penalty for trim drag reduction. Don’t know if it would be a net gain.
Isn't this the reason why the Su-57's engines are angled slightly outwards? I'd guess the Su-57 cruises at a slight positive AoA, like the Flankers do then the TVC would allow to have the engines point straight backwards in cruising flight.
Btw, how common is it for jets to cruise at positive AoA, particularly stealth ones? I'd assume this increases the RCS somewhat.
Like 100% common, otherwise they would fall from the sky.
Trimming is another question. There TVC can be more efficient than aerodynamic surfaces, but specifically when the CoL transitions backwards in supersonic flight, the contribution of deflected TVC would be negative lift, so it is also not ideal. Maybe the LEVCONS are the best option there, always considering that the unstable design should allow to reduce the TVC deflection to a minimum in supersonic flight.
Pitching the aircraft isn't the only way to generate lift - there's vortex lift and the aerodynamic shape of the wings themselves.
I just realized that the engines are moving on a wrong axis for the scheme I proposed to work - outward angled engines with outward facing axis of TVC rotation means that at positive AoA, you need to rotate the nozzles down, not up to get the thrust vector to line up with the centerline of the aircraft. This also doesn't help with a backwards center of lift, as that assumes that the aircraft has a natural tendency to pitch down - angling the thrust downwards does the opposite of trimming.
Afaik Levcons aren't really pitch control devices - aerodynamically speaking they roughly change the virtual 'angle of attack' of the wings in terms of vortex generation, so they change the amount of lift the wings generate, not the location at which the forces appear. I'd say they help getting rid of induced drag instead of trim drag - though they can probably help with reducing the counterbalancing forces the tails or the TVC has to generate - that's why I asked the AoA question - upwards deflected Levcons have a similar lifting effect to pitching the aircraft itself.
Edit: Now that I think about it, keeping the flow attached might be more useful than having vortex lift, so the Su-57 might actually be flying at an AoA with its levcons slightly shifter downwards.
Those LEVCON's are something really special and unique aerodynamic feature of the Su-57 as those LERX's are for the FFF ( Flanker Family Fighters).
Materials of the Polish and Chinese authors....
'LEVCON vs LERX'
''Amid actuated devices such as leading-edge flaps, trailing-edge flaps, or slats a new type of device has been trending in recent years. This device is called the leading-edge vortex controller (LEVCON), and it is a continuation of an already existing and widely used aerodynamic solution called the leading-edge root extension (LERX). In comparison, LEVCON is designed to operate similarly to LERX, with its aim being to generate lift-augmenting vortices, i.e., vortex lift, at high angles of attack. While LERX is a fixed aerodynamic component of the aircraft, LEVCONs are actuated devices, which improve their performance in areas beyond high-angle-of-attack scenarios.
In fact, this aerodynamic solution might have more significance in classified research, as it is currently implemented in only one operational aircraft type: the Russian Sukhoi Su-57.''
Leading-Edge Vortex Controller (LEVCON) Influence on the Aerodynamic Characteristics of a Modern Fighter Jet
The purpose of this paper is to assess the influence of a novel type of vortex creation device called the leading-edge vortex controller (LEVCON) on the aerodynamic characteristics of a fighter jet. LEVCON has become a trending term in modern military aircraft in recent years and is a...
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.
www.twz.com
www.aviaport.ru
www.mdpi.com
