"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
