JF-17 Block-3 -- Updates, News & Discussion

[ARMalik]

"Baolong" BLOCK3's radar finally arrived in Nanjing
Original Asia Railway StationAsia Railway StationYesterday
"Jane's Defense Weekly" announced today that the Pakistani Air Force will begin to receive the first batch of 12 "Shenlong" two-seater fighters. Meanwhile, Pakistani officials announced that they have identified the "Shenlong" BLOCK3 batch of radars. They finally selected the KLJ-7A active phased array radar at the 14th Nanjing Institute.

Earlier, there have been photos showing the status of the first prototype of the "Baolong" BLOCK3 fighter. The aircraft has not been equipped with radar, but the front fuselage structure and shape of the front fuselage are different from those of the BLOCK 2. This time, the Pakistani side officially confirmed that The end to the question of what type of radar of the "Baolong" BLOCK 3 will be.


Although the LKF-601E air-cooled active phased array radar of the Wuxi Institute 617 has the advantage of in-situ replacement (on the earlier version of the JF-17 fighter), it may be in the middle of the future extension of the second batch of JF-17 fighters in the future. Obtained new opportunities, but finally failed to be selected in the competition of BLOCK 3 batch fighter radar.

So KLJ-7A and LKF601E do not seem to have much difference in performance parameters such as maximum detection distance. On what basis is it selected?

Here we will introduce the advantages and disadvantages of air cooling and water cooling technology used in radar, and the differences between LKF-601E and KLJ-7A in cooling technology.

First of all, the selling point of the LKF601E radar developed by Wuxi 607 is "the world's first air-cooled active phased array radar". At the 2018 Zhuhai Air Show, AVIC Group demonstrated the model of this radar for the first time in the exhibition hall.


From the appearance of the model, the number of T / R originals of this radar may be close to that of the French "Gust" RBE-2 radar, about 800, and the output power of its T / R originals may also be somewhat Limit to reduce heat.

The author went through some papers, and can find many design schemes of air-cooled phased array antennas, but most of them are large-scale antennas for ground use, because air-cooling has certain requirements on antenna size and thickness. For the solution of airborne active array antenna cooling, I also saw several related articles. It should be said that basically it is necessary to cooperate with measures such as reducing output power and reducing T / R element density to ensure the normal operation of the radar.

In addition, the air-cooled radar has a problem that is not easy to solve, that is, as the altitude rises, the air density becomes thinner, which causes its heat dissipation capacity to decrease sharply.

According to relevant empirical values, at an altitude of 35,000 feet, the air flow of the air-cooled system will be reduced to 40% of the sea level.


Therefore, active phased array radars that require high heat dissipation use liquid cooling on most modern fighters.

We know that Pakistan is a country with a high average altitude, especially the Indian-Pakistani border area is a world-famous alpine mountain. This is an additional burden for air-cooled radar, and it may be necessary to further reduce power or limit use time. .

Compared with the LKF601E, the KLJ-7A radar uses a design scheme similar to the APG-81 on the US F-16V fighter, that is, the antenna itself is water-cooled, and then the existing air-cooling device on the fighter is used to cool the water-cooling system Of heat. The design of this water-cooled antenna + air-cooled system is less expensive than a comprehensive redesign of the front fuselage and an increase in heat dissipation.

Therefore, we saw that the front body of the J-10B \ C fighter with a water-cooled design was redesigned, and the "cheek" was increased. Although the "chuck" also stands out a bit from the BLOCK2 prototype, But it is not obvious.

The headspace dimensions of the Xiaolong fighter have reached the level of F-16 and J-10 fighters, so the aircraft can be equipped with mainstream airborne radar, without the need to modify the Israeli F-5E, "lion", etc. Like the plan, a "big nose" is installed on the fighter aircraft, and the performance is still far below the mainstream advanced airborne radar after modification.

From the data that can be confirmed at present, the parameters of the KLJ-7A's antenna T / R originals and other parameters are in the same grade as the APG-83. The published maximum detection distance, the number of simultaneous tracking / combat targets, and SAR imaging accuracy etc Basically equivalent, it can be inferred that the two are in the same grade.



Israel EL / M-2052 radar

After installing the KLJ-7A radar on the Biaolong Block3, its international competitiveness will increase significantly. Except for the US APG-83, only the ES-05 of Leonardo in Italy (has been approved by the Swedish "Gripen"). NG selection) radar can be compared with it, Israel's EL2052 radar is a lower grade.

As a result, the Dragon BLOCK3 can compete with the Gripen NG and F-16V at a much lower price.

However, the LKF601E is not without its way out. This type of radar can be directly installed in-situ in the head space of "Baolong" BLOCK1 and 2, directly replacing the old machine-scan radar. It is entirely possible to use it in the mid-life extension of various third-generation aircraft in the future. For example, Venezuela's F-16 modification is not impossible, and at the same time its performance is much higher than the Israeli EL-2052 radar of the same weight and size level. From this point of view, perhaps the future of this type of radar lies in foreign technical cooperation.

https://mp.weixin.qq.com/s/Y3z1Ev1RhEswHmjOytznpQ

I am sorry but this writer is a freaking Clown. So according to this writer, at an altitude of 35,000 feet, the air flow of the air-cooled system will be reduced to 40% of the sea level. That maybe correct but what he very conveniently forget to mention is that the corresponding air temperature drops as well.

So the basic question is why do you need certain air-flows? You need certain air-flow because you want certain amount of heat to dissipate from the on-board system/s of the fighter. But this air-flow will be varied by the system taking into account the outside air temperature. At an altitude of 35,000 the outside air temperature is usually around -40° C to -57° C. So technically you do not need the same Air 'Flow rate' at higher altitudes than the Flow-rate required at lower altitudes. In other words, less Air-flow would be required at higher altitudes to dissipate system heat due to lower external temperatures.

Not only this, the onboard fighter-jet systems components can be manufactured using gallium nitride instead of Silicon as Gallium Nitride components can withstand very high temperatures .

 

[Aasimkhan]

I am sorry but this writer is a freaking Clown. So according to this writer, at an altitude of 35,000 feet, the air flow of the air-cooled system will be reduced to 40% of the sea level. That maybe correct but what he very conveniently forget to mention is that the corresponding air temperature drops as well.

So the basic question is why do you need certain air-flows? You need certain air-flow because you want certain amount of heat to dissipate from the on-board system/s of the fighter. But this air-flow will be varied by the system taking into account the outside air temperature. At an altitude of 35,000 the outside air temperature is usually around -40° C to -57° C. So technically you do not need the same Air 'Flow rate' at higher altitudes than the Flow-rate required at lower altitudes. In other words, less Air-flow would be required at higher altitudes to dissipate system heat due to lower external temperatures.

This is all theoretical. Actual lab testing will tell us that after adjusting for reduction in air flow as well as temperature how much intervention will be required if at all.

 

[ARMalik]

This is all theoretical. Actual lab testing will tell us that after adjusting for reduction in air flow as well as temperature how much intervention will be required if at all.

I have added extra to my above post. Another factor are the material utilised for the electronic components, example, Gallium Nitride components instead of silicon which can withstand much higher temperatures.

 

[mourning sage]

I am sorry but this writer is a freaking Clown. So according to this writer, at an altitude of 35,000 feet, the air flow of the air-cooled system will be reduced to 40% of the sea level. That maybe correct but what he very conveniently forget to mention is that the corresponding air temperature drops as well.

So the basic question is why do you need certain air-flows? You need certain air-flow because you want certain amount of heat to dissipate from the on-board system/s of the fighter. But this air-flow will be varied by the system taking into account the outside air temperature. At an altitude of 35,000 the outside air temperature is usually around -40° C to -57° C. So technically you do not need the same Air 'Flow rate' at higher altitudes than the Flow-rate required at lower altitudes. In other words, less Air-flow would be required at higher altitudes to dissipate system heat due to lower external temperatures.

Not only this, the onboard fighter-jet systems components can be manufactured using gallium nitride instead of Silicon as Gallium Nitride components can withstand very high temperatures .

Not sure about the nature of radars but as far as heat exchange is concerned, the huge temperature differential will also cause heat dissipation through radiation.

The exact magnitudes depend on several factors before giving a verdict if at high altitudes heat dissipation rates are the same or at the very least bearable.

 

[AMRAAM]

Thank you for the confirmation.

So now we have two sources confirming that it indeed is an Air-Cooled KLJ-7A AESA version.
1) Janes
2) Alan Warnes Twitter Account
This is the confirmation I was waiting for.
Kudos to everyone.

The Janes article was also written by Alan Warnes so it is a single source actually.

https://twitter.com/x/status/1224765678303039489

 

[ARMalik]

Not sure about the nature of radars but as far as heat exchange is concerned, the huge temperature differential will also cause heat dissipation through radiation.

The exact magnitudes depend on several factors before giving a verdict if at high altitudes heat dissipation rates are the same or at the very least bearable.

Right - so what are these 'Several' factors - care to elaborate? I am well aware of the ΔT requirements. Tell me something - who designs a system without taking into basic considerations such as ΔT, ΔP, Flow rates, heat rejection requirements, etc?

 

[araz]

The author says that the antenna of KLJ7A is liquid cooled and this liquid cooling system is cooled by air.
Anyone knows what he is talking about and whether there is accuracy in his statements. It isinteresting times ahead for the JFT though.
A

 

[ARMalik]

The author says that the antenna of KLJ7A is liquid cooled and this liquid cooling system is cooled by air.
Anyone knows what he is talking about and whether there is accuracy in his statements. It isinteresting times ahead for the JFT though.
A

The liquid he is talking about is a 'Refrigerant'. This 'Refrigerant' goes through the 'Refrigerant' Cycle, and ejects heat to the atmosphere (air). Hence it is called an 'Air-Cooled' system. And hence my posts above outlining the flawed assumption of the author.

 

[kursed]

I believe at some point, a discussion happened on this forum, where JF-17’s atmosphere control system was made responsible for cooling the radar array as well. And that it was done by us.
Could that be used here?

 

[aliyusuf]

The Janes article was also written by Alan Warnes so it is a single source actually.

https://twitter.com/x/status/1224765678303039489

Since he has come out and corroborated what he has written in the article, on his own twitter account, it puts emphasis that he is standing by what he has written. Generally his info about PAF is sound. I greatly appreciated his 2013 AFM piece the "Amazing Mirages" about the history and induction details of the PAF Mirages.

 

[StormBreaker]

"Baolong" BLOCK3's radar finally arrived in Nanjing
Original Asia Railway StationAsia Railway StationYesterday
"Jane's Defense Weekly" announced today that the Pakistani Air Force will begin to receive the first batch of 12 "Shenlong" two-seater fighters. Meanwhile, Pakistani officials announced that they have identified the "Shenlong" BLOCK3 batch of radars. They finally selected the KLJ-7A active phased array radar at the 14th Nanjing Institute.

Earlier, there have been photos showing the status of the first prototype of the "Baolong" BLOCK3 fighter. The aircraft has not been equipped with radar, but the front fuselage structure and shape of the front fuselage are different from those of the BLOCK 2. This time, the Pakistani side officially confirmed that The end to the question of what type of radar of the "Baolong" BLOCK 3 will be.


Although the LKF-601E air-cooled active phased array radar of the Wuxi Institute 617 has the advantage of in-situ replacement (on the earlier version of the JF-17 fighter), it may be in the middle of the future extension of the second batch of JF-17 fighters in the future. Obtained new opportunities, but finally failed to be selected in the competition of BLOCK 3 batch fighter radar.

So KLJ-7A and LKF601E do not seem to have much difference in performance parameters such as maximum detection distance. On what basis is it selected?

Here we will introduce the advantages and disadvantages of air cooling and water cooling technology used in radar, and the differences between LKF-601E and KLJ-7A in cooling technology.

First of all, the selling point of the LKF601E radar developed by Wuxi 607 is "the world's first air-cooled active phased array radar". At the 2018 Zhuhai Air Show, AVIC Group demonstrated the model of this radar for the first time in the exhibition hall.


From the appearance of the model, the number of T / R originals of this radar may be close to that of the French "Gust" RBE-2 radar, about 800, and the output power of its T / R originals may also be somewhat Limit to reduce heat.

The author went through some papers, and can find many design schemes of air-cooled phased array antennas, but most of them are large-scale antennas for ground use, because air-cooling has certain requirements on antenna size and thickness. For the solution of airborne active array antenna cooling, I also saw several related articles. It should be said that basically it is necessary to cooperate with measures such as reducing output power and reducing T / R element density to ensure the normal operation of the radar.

In addition, the air-cooled radar has a problem that is not easy to solve, that is, as the altitude rises, the air density becomes thinner, which causes its heat dissipation capacity to decrease sharply.

According to relevant empirical values, at an altitude of 35,000 feet, the air flow of the air-cooled system will be reduced to 40% of the sea level.


Therefore, active phased array radars that require high heat dissipation use liquid cooling on most modern fighters.

We know that Pakistan is a country with a high average altitude, especially the Indian-Pakistani border area is a world-famous alpine mountain. This is an additional burden for air-cooled radar, and it may be necessary to further reduce power or limit use time. .

Compared with the LKF601E, the KLJ-7A radar uses a design scheme similar to the APG-81 on the US F-16V fighter, that is, the antenna itself is water-cooled, and then the existing air-cooling device on the fighter is used to cool the water-cooling system Of heat. The design of this water-cooled antenna + air-cooled system is less expensive than a comprehensive redesign of the front fuselage and an increase in heat dissipation.

Therefore, we saw that the front body of the J-10B \ C fighter with a water-cooled design was redesigned, and the "cheek" was increased. Although the "chuck" also stands out a bit from the BLOCK2 prototype, But it is not obvious.

The headspace dimensions of the Xiaolong fighter have reached the level of F-16 and J-10 fighters, so the aircraft can be equipped with mainstream airborne radar, without the need to modify the Israeli F-5E, "lion", etc. Like the plan, a "big nose" is installed on the fighter aircraft, and the performance is still far below the mainstream advanced airborne radar after modification.

From the data that can be confirmed at present, the parameters of the KLJ-7A's antenna T / R originals and other parameters are in the same grade as the APG-83. The published maximum detection distance, the number of simultaneous tracking / combat targets, and SAR imaging accuracy etc Basically equivalent, it can be inferred that the two are in the same grade.



Israel EL / M-2052 radar

After installing the KLJ-7A radar on the Biaolong Block3, its international competitiveness will increase significantly. Except for the US APG-83, only the ES-05 of Leonardo in Italy (has been approved by the Swedish "Gripen"). NG selection) radar can be compared with it, Israel's EL2052 radar is a lower grade.

As a result, the Dragon BLOCK3 can compete with the Gripen NG and F-16V at a much lower price.

However, the LKF601E is not without its way out. This type of radar can be directly installed in-situ in the head space of "Baolong" BLOCK1 and 2, directly replacing the old machine-scan radar. It is entirely possible to use it in the mid-life extension of various third-generation aircraft in the future. For example, Venezuela's F-16 modification is not impossible, and at the same time its performance is much higher than the Israeli EL-2052 radar of the same weight and size level. From this point of view, perhaps the future of this type of radar lies in foreign technical cooperation.

https://mp.weixin.qq.com/s/Y3z1Ev1RhEswHmjOytznpQ

This guy also reads pdf, these are our views...

 

[mourning sage]

Right - so what are these 'Several' factors - care to elaborate? I am well aware of the ΔT requirements. Tell me something - who designs a system without taking into basic considerations such as ΔT, ΔP, Flow rates, heat rejection requirements, etc?

Dude ease off. My comment was in support of yours.

 

[Pandora]

"Baolong" BLOCK3's radar finally arrived in Nanjing
Original Asia Railway StationAsia Railway StationYesterday
"Jane's Defense Weekly" announced today that the Pakistani Air Force will begin to receive the first batch of 12 "Shenlong" two-seater fighters. Meanwhile, Pakistani officials announced that they have identified the "Shenlong" BLOCK3 batch of radars. They finally selected the KLJ-7A active phased array radar at the 14th Nanjing Institute.

Earlier, there have been photos showing the status of the first prototype of the "Baolong" BLOCK3 fighter. The aircraft has not been equipped with radar, but the front fuselage structure and shape of the front fuselage are different from those of the BLOCK 2. This time, the Pakistani side officially confirmed that The end to the question of what type of radar of the "Baolong" BLOCK 3 will be.


Although the LKF-601E air-cooled active phased array radar of the Wuxi Institute 617 has the advantage of in-situ replacement (on the earlier version of the JF-17 fighter), it may be in the middle of the future extension of the second batch of JF-17 fighters in the future. Obtained new opportunities, but finally failed to be selected in the competition of BLOCK 3 batch fighter radar.

So KLJ-7A and LKF601E do not seem to have much difference in performance parameters such as maximum detection distance. On what basis is it selected?

Here we will introduce the advantages and disadvantages of air cooling and water cooling technology used in radar, and the differences between LKF-601E and KLJ-7A in cooling technology.

First of all, the selling point of the LKF601E radar developed by Wuxi 607 is "the world's first air-cooled active phased array radar". At the 2018 Zhuhai Air Show, AVIC Group demonstrated the model of this radar for the first time in the exhibition hall.


From the appearance of the model, the number of T / R originals of this radar may be close to that of the French "Gust" RBE-2 radar, about 800, and the output power of its T / R originals may also be somewhat Limit to reduce heat.

The author went through some papers, and can find many design schemes of air-cooled phased array antennas, but most of them are large-scale antennas for ground use, because air-cooling has certain requirements on antenna size and thickness. For the solution of airborne active array antenna cooling, I also saw several related articles. It should be said that basically it is necessary to cooperate with measures such as reducing output power and reducing T / R element density to ensure the normal operation of the radar.

In addition, the air-cooled radar has a problem that is not easy to solve, that is, as the altitude rises, the air density becomes thinner, which causes its heat dissipation capacity to decrease sharply.

According to relevant empirical values, at an altitude of 35,000 feet, the air flow of the air-cooled system will be reduced to 40% of the sea level.


Therefore, active phased array radars that require high heat dissipation use liquid cooling on most modern fighters.

We know that Pakistan is a country with a high average altitude, especially the Indian-Pakistani border area is a world-famous alpine mountain. This is an additional burden for air-cooled radar, and it may be necessary to further reduce power or limit use time. .

Compared with the LKF601E, the KLJ-7A radar uses a design scheme similar to the APG-81 on the US F-16V fighter, that is, the antenna itself is water-cooled, and then the existing air-cooling device on the fighter is used to cool the water-cooling system Of heat. The design of this water-cooled antenna + air-cooled system is less expensive than a comprehensive redesign of the front fuselage and an increase in heat dissipation.

Therefore, we saw that the front body of the J-10B \ C fighter with a water-cooled design was redesigned, and the "cheek" was increased. Although the "chuck" also stands out a bit from the BLOCK2 prototype, But it is not obvious.

The headspace dimensions of the Xiaolong fighter have reached the level of F-16 and J-10 fighters, so the aircraft can be equipped with mainstream airborne radar, without the need to modify the Israeli F-5E, "lion", etc. Like the plan, a "big nose" is installed on the fighter aircraft, and the performance is still far below the mainstream advanced airborne radar after modification.

From the data that can be confirmed at present, the parameters of the KLJ-7A's antenna T / R originals and other parameters are in the same grade as the APG-83. The published maximum detection distance, the number of simultaneous tracking / combat targets, and SAR imaging accuracy etc Basically equivalent, it can be inferred that the two are in the same grade.



Israel EL / M-2052 radar

After installing the KLJ-7A radar on the Biaolong Block3, its international competitiveness will increase significantly. Except for the US APG-83, only the ES-05 of Leonardo in Italy (has been approved by the Swedish "Gripen"). NG selection) radar can be compared with it, Israel's EL2052 radar is a lower grade.

As a result, the Dragon BLOCK3 can compete with the Gripen NG and F-16V at a much lower price.

However, the LKF601E is not without its way out. This type of radar can be directly installed in-situ in the head space of "Baolong" BLOCK1 and 2, directly replacing the old machine-scan radar. It is entirely possible to use it in the mid-life extension of various third-generation aircraft in the future. For example, Venezuela's F-16 modification is not impossible, and at the same time its performance is much higher than the Israeli EL-2052 radar of the same weight and size level. From this point of view, perhaps the future of this type of radar lies in foreign technical cooperation.

https://mp.weixin.qq.com/s/Y3z1Ev1RhEswHmjOytznpQ

Why is he comparing KLJ7A detection range to APG 83? Isnt the detection range of KLJ7A just 170km compared to almost 300km of APG83? OR am i confusing something here?

 

[Pakistani Fighter]

300km of APG83

You mean the one of F16V? I think it is 130km

 

[NA71]

"However, the LKF601E is not without its way out. This type of radar can be directly installed in-situ in the head space of "Baolong" BLOCK1 and 2, directly replacing the old machine-scan radar."

This particular part of article supports earlier claims that some JF-17s B2 used in Operation Swift Retort were equipped with AESA LKF601E radars @TheTallGuy @airomerix