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

[m52k85]

Hi,

If he has a PhD in engineering and work experience---then in his field of work---just by looking at a picture he would be able to tell what the item is and what its purpose is.

A simple PhD without any field experience does not count for much in analysis.

Yes thats why I asked him, and he obliged with the answer.

 

[Aesterix]

Difference in mounting of the Block 3 vs Block 2. ... interesting the plate/slot fits in with the LKF601E AESA radar ( I have been re-educated by men in black suites and glasses) ... the plate fits the KLJ-7A
View attachment 776030

View attachment 776033

View attachment 776035

Hi,
I don't understand.
The plate is square and KLJ-7A radar is round?

 

[Marker]

You are getting confused by the circular cover that could possibly be hiding a square hole. If you notice, the circular cover is bolted into place. Also, the picture of KLJ-7A is merely a representation. Let us wait for PAF/PAC to confirm, but the best assumption seems to be KLJ-7A so far.

Also, if you read the hints given by @messiach, the two phase cooling would utilize a fuel tank as a heat exchanger. This fuel tank wouldn't be used to power the aircraft, and would be quite small in size.

Using aircraft fuel to cool radar housing is unusual. At least, I am not aware of such arrangement in any of the existing military aircraft.

Aircraft fuel tank designated for use in cooling of radar is very remote. Instead liquid coolants which are being used in refrigeration system could be used and stored in a "storage tank/sink".

Though "hybrid arrangement" ie compressed air and liquid coolant combination can be used for radar housing cooling, but the according to Alan Warnes PAF selected air cooled version of KLJ-7A AESA radar (Janes' Feb 2020 issue) for JF-17 Blk 3.

 

[CriticalThought]

Using aircraft fuel to cool radar housing is unusual. At least, I am not aware of such arrangement in any of the existing military aircraft.

Aircraft fuel tank designated for use in cooling of radar is very remote. Instead liquid coolants which are being used in refrigeration system could be used and stored in a "storage tank/sink".

Though "hybrid arrangement" ie compressed and liquid coolant combination can be used for radar housing cooling, but the according to Alan Warnes PAF selected air cooled version of KLJ-7A AESA radar (Janes' Feb 2020 issue) for JF-17 Blk 3.

Fuel tank being used as a 'Heat Sink' sounds like an exaggeration.

Try reading all the posts in the thread before you raise questions on someone's statement

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

Before we come to your questions, let us first review available information on how liquid cooling is achieved historically Active Electronically Steered Arrays - A Maturing Technology (ausairpower.net) US designs employ a polyalphaolefin (PAO) coolant similar to a synthetic hydraulic fluid. A...

defence.pk

 

[ARMalik]

Try reading all the posts in the thread before you raise questions on someone's statement

You are out of your depth. Let it go, specially when I have not quoted your post. I am not interested.

 

[Marker]

Try reading all the posts in the thread before you raise questions on someone's statement

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

Before we come to your questions, let us first review available information on how liquid cooling is achieved historically Active Electronically Steered Arrays - A Maturing Technology (ausairpower.net) US designs employ a polyalphaolefin (PAO) coolant similar to a synthetic hydraulic fluid. A...

defence.pk

Why dedicated jet fuel should be used for cooling purpose? It will be more efficient and effective to use liquid coolants instead of jet fuel. Hint: efficient storage and dissipation of heat in liquid coolant as compared to dedicated jet fuel.

PS: 1. Location of coolant storage/sink should be near the radar housing to avoid extra plumbing.

2. Whatever we are discussing are our assumptions based on our inferences made over the available facts in whatever form.

 

[Shabi1]

If air-cooled version of KLJ-7A AESA radar is selected for JF-17 Blk 3s then these plumbings seen outside the bottom of the cockpit are coming from the engine compressor. High pressure air is being used as coolant.

"One way of maintaining the working temperature of the radome is to use coolant based refrigeration techniques or recirculation of pressurised air within the housing in order to maintain an optimum temperature within the radome."

Source:

EP2387809B1 - A radome and method of cooling radar components - Google Patents

I doubt air circulation being done in radome as there are no inlets. With air cooled in case of JF-17 we are probably getting a more efficient radar with less cooling needs, the heat exchange system itself is probably not changed.
Blk-3 radar was chosen couple of months if not just a year ago, that means it was designed to accept (power/cooling) any of the radar options KLJ-7A (non aircooled)/ Grifo-E and have spare cooling for future radars.

AVIC pitches air-cooled AESA radar for JF-17

The Aviation Industry Corporation of China’s (AVIC) 607 research institute announced that it completed the development of an air-cooled AESA radar

quwa.org

" The transceiver modules (TRM) of an AESA radar generate considerable heat that must be dissipated for the TRMs to function reliably (and not incur damage). This is currently done through liquid cooling, which necessitates additional space for the cooling system and additional electrical power. In contrast, the LETRI AESA radar draws from the cooling methods of current pulse-Doppler radars, which implies that this AESA radar can be fit to small aircraft with relative ease and at low-cost.

.....

The LETRI radar could potentially be a simpler affordable avenue for upgrading serving Block-I and Block-II. In fact, AVIC appears to be banking on that reality to secure orders – losing the Block-III to bid to NRIET or Leonardo would not preclude it from selling radars to the PAF. The PAF’s JF-17 Block-I/IIs would benefit from the benefits of an AESA radar without necessitating significant structural changes. "

 

[CriticalThought]

You are out of your depth. Let it go, specially when I have not quoted your post. I am not interested.

Actually, you have zero intellectual input on the forum. You are a typical case of high entropy, low information content contributor. And I will quote you, as I please and when I please.

 

[CriticalThought]

Why dedicated jet fuel should be used for cooling purpose? It will be more efficient and effective to use liquid coolants instead of jet fuel. Hint: efficient storage and dissipation of heat in liquid coolant as compared to dedicated jet fuel.

PS: 1. Location of coolant storage/sink should be near the radar housing to avoid extra plumbing.

2. Whatever we are discussing are our assumptions based on our inferences made over the available facts in whatever form.

Well, why jet fuel would be used is a good question for the American designers who initiated this. But doing even a cursory search on the internet produces this:

JP-8+100: The development of high-thermal-stability jet fuel (Journal Article) | OSTI.GOV

The U.S. Department of Energy's Office of Scientific and Technical Information

www.osti.gov

I am surprised people cannot make such a tiny effort for themselves, but expound on the forum as if standing on a pulpit.

 

[The Eagle]

PAO

This.

So the RD-93 can manage that much?

Studies found that liquid cooling results in max KW for consistent performance of 1000-+ TRM AESA. I don't know the exact numbers generated in this case but it was majority found that liquid can do much better than Air Cooled. However, to get max power for AESA, the hybrid was found to be better. Air cooling directed for less heat generating equipment and liquid for the high heat generating equipment. Suh a mix, as per my understanding, then minimizes the load on one cooling procedure and so for the compressor and supplying fans as well.

OK, here's another problem
The forward bulkhead on Blk 3 has a square hole. But KLJ-7A has a rounded antenna.
However LKF601E does have a square antenna.
So what's happening here?View attachment 777510

@Tempest II has already clarified much on this.

 

[Tempest II]

Hi,
I don't understand.
The plate is square and KLJ-7A radar is round?

Check this.

https://defence.pk/pdf/attachments/type-klj-7a-airborne-aesa-radar-for-junk-f-17-block-iii-mock-up-of-twin-seater-version-jf-17-jpg.776035/

The front bit is circular ... and the back end is squar'ish

 

[The Eagle]

national debate did this interview

why is it not on Youtube ?

It's on Facebook.
Click on the link

Full Program : Exclusive "Grand National Debate" with PAF at PAC Kamra | By Jameel Farooqui | Facebook

Full Program : Exclusive "Grand National Debate" with PAF at PAC Kamra

fb.watch

Hopefully you got the link. Even I shared live youtube link which had the program.

 

[The Eagle]

Pee Hech Dees!

I am surprised people cannot make such a tiny effort for themselves, but expound on the forum as if standing on a pulpit.

No need to go that route against anyone. People have the right to share their opinion and you can argue the matter with counter arguments or further knowledge. Such cheap shots merely downgrades the discussion. Lest not enforce our knowledge on others. Continue with discussion.

Regards,

 

[Marker]

Well, why jet fuel would be used is a good question for the American designers who initiated this. But doing even a cursory search on the internet produces this:

JP-8+100: The development of high-thermal-stability jet fuel (Journal Article) | OSTI.GOV

The U.S. Department of Energy's Office of Scientific and Technical Information

www.osti.gov

I am surprised people cannot make such a tiny effort for themselves, but expound on the forum as if standing on a pulpit.

I am not aware of any arrangement in any military aircraft including F-35 using dedicated jet fuel for radar cooling.

The referred paper mentions that heat sink capability of JP-8-100 is improved by 50%, but does not compare with other liquid coolants.

Furthermore are we sure that PAF is using JP-8-100.

Lastly it would be better, if you avoid personal comments. (Bold for your reference).

This forum is for discussion. Respected members post their views on the topic of discussion based on the inference they make on available facts. There is a possibility that some facts may be missed by them, but it does not mean that you have the right to challenge their omission, instead it would be better to steer the discussion by adding your input, hence maintaining a cordial environment.

 

[CriticalThought]

I am not aware of any arrangement in any military aircraft including F-35 using dedicated jet fuel for radar cooling.

The referred paper mentions that heat sink capability of JP-8-100 is improved by 50%, but does not compare with other liquid coolants.

Furthermore are we sure that PAF is using JP-8-100.

Lastly it would be better, if you avoid personal comments. (Bold for your reference).

This forum is for discussion. Respected members post their views on the topic of discussion based on the inference they make on available facts. There is a possibility that some facts may be missed by them, but it does not mean that you have the right to challenge their omission, instead it would be better to steer the discussion by adding your input, hence maintaining a cordial environment.

In that case, I will let you do your own research, because the answers you are looking for are very readily available.