forgive me for asking what may seem like a stupid question but if you are detected as soon as you radiate then how would 2 stealth aircraft fight against each other in a AWACS free environment? or will they never ever do so?
I wish I have enough knowledge on this to explain, what i said above was from a scientific pov that is for basic principle of a stealth configuration flying vehicle. Materials of choice, very specific aerodynamic shaping, reduced rcs frontal shape etc all are enabling tech for a stealth jet, similarly the very important possibly the most important part is developing the passive sensors because when airborne the way to detect is via electronic means. So to have non radiating element and yet still be able to detect the adversary before it knows of your presence is the crux of the thing.
About the engagement, that part is for the military people to devise accordingly what the jet capability offers to you. As we know there are many slips between what is claimed vs what is on hand, so you try to use the jet & the capability it offers to the best way possible. This part is for the military to create a training plan, engagement rule etc. The scientists who built the jet can not tell or teach about this part. They can only make the jet better functionally, by making it more agile, lighter, quicker, suppress any telling sign of possible detection via testing, make better avionics & sensor suite ie provide all the tools. Then the air force has to come up with a plan how to use this jet with stealth to a good practical use.
I have also heard that our virupaksha sorta promises us a decent detection range against stealth targets for proper BVR combat. Is this true? would this passive detection system make it useless or will the detection range be long enough(150-200km+) for it to not matter nearly as much?
Very hard to quantify until virupaksha is made & tested on ground rig, then flown on trial jet nose mounted. There is some performance drop off in real ambient condition. Passive detection stands a better chance in this regard ie much late detection by enemy. Surprising is very crucial element in air game. Since we can not predict exactly how far or when it will detect, but only provide a possible set of data based on experimentation. Remember this data need to be field proven & there is often anomaly in that, such dataset are treated as highly confidential & restricted. Usually 200km or more far apart poses little threat, in such engagement one side want to be seen so the other is deterred from any aggressive action.
Especially against the j35 or the j20 which will be our main adversaries for the next 10 years.
Do you think the passive detection systems on the j20 is good enough compared to Israeli or American systems while not underestimating the Chinese
I have data on neither so your take is as good as mine. Even if there is surprising element, that surprise work for one time only. Nobody pits entire inventory against each other so the tactics SOP is evolved based on real time engagement. That flexibility is always there to react as per the threat you face.