Pravin Sawhney questions the Indian HGV test. Apparently the parameters of the test is sub par. So this makes India's HGV performance questionable.
Indian Military News, Reports, Data, etc.
- Thread starter bd popeye
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Well they claim they fired their scramjet for 20s. The US tested their scramjet in 1990s or 2000s HGV tests at around 10s. Chinese ones have done tests for 20s in disclosed scramjet running. The weaponised vehicles (Wu-14 and DF-ZF as two useless designations) that are air breathing are probably capable of running for considerably longer.
Scramjets can absolutely operate around Mach 6 and even slightly under so there's no doubt there. But there's no indication of how far the Indian test vehicle traveled and whether it rides shockwaves. How controllable is it? What sort of trajectory did it run? Of course they probably won't give that many details but most of these are observable especially by China due to how close it is to India.
The US observed many Chinese HGV flight tests in the past and reported on them in white papers without giving too much detail except to mention that China has developed mach 10 capable waveriders that are controllable and will be weaponised. We've already seen the DF-17 boosted HGV. It's huge and this one probably isn't an air breather. The DF-100 is scramjet powered and features an intake geometry that looks similar to the Xingkong or starry sky mockup.
It's far more likely India just boosted a small table sized demonstrator vehicle. Probably not even the size of the X-43. It's very preliminary flight test that they attempted in 2019 but the rocket failed to deliver the vehicle to desired flight parameters. This time they succeeded. It's a LONG way from controlling the vehicle and then guiding it. They'll also need to scale up the whole thing by some factor if they want to weaponise it for any imaginable purpose. It's very far from what most Indians are celebrating it as. This is basically where China was around 2005/06 with initial small scale HGV flight tests. The same place the US was back in the 1990s if not much earlier. Same with the Soviets and Russians.
It should be remembered that scramjets and ramjets are not difficult in fact much simpler and easier than turbofans to design and manufacture.
The hardest part of developing a useful weaponised HGV is scaling the whole thing up which India is nowhere near, along with controlling its flight and the specifics of shockwave riding combined with guided and controlled waveriding. No details on this wrt the Indian test. Judging by the mock-up of this DRDO HGV, it is not a waverider and just a vehicle with a scramjet boosted to speed and altitude by rocket. It could be intentionally keeping speeds relatively low hypersonic so it can make use of aerodynamic surfaces for control and turns. Although this test vehicle was probably not controllable or have any significant range due to scramjet operation limited to 20s and not taking advantage of shockwave riding. Without being controllable and guide-able, it would be useless as a weapon. Obviously their end goal is to develop all the above.
Looking at the Agni booster, the size must be quite a lot smaller than the X-43 which is already a tiny demonstrator vehicle. With this test they're probably just aiming to test the aerodynamics and actual performance of their scramjet. Using Israeli hypersonic wind tunnels as well with no domestic supercomputers to assist with the program, it may take decades longer to weaponise this than it took China which was around 10 years - between rumours of HGV initial tests of smaller models in 2005ish to 2014 US confirmed flight tests of full scale HGV.
The hardest part of developing a useful weaponised HGV is scaling the whole thing up which India is nowhere near, along with controlling its flight and the specifics of shockwave riding combined with guided and controlled waveriding. No details on this wrt the Indian test. Judging by the mock-up of this DRDO HGV, it is not a waverider and just a vehicle with a scramjet boosted to speed and altitude by rocket. It could be intentionally keeping speeds relatively low hypersonic so it can make use of aerodynamic surfaces for control and turns. Although this test vehicle was probably not controllable or have any significant range due to scramjet operation limited to 20s and not taking advantage of shockwave riding. Without being controllable and guide-able, it would be useless as a weapon. Obviously their end goal is to develop all the above.
Looking at the Agni booster, the size must be quite a lot smaller than the X-43 which is already a tiny demonstrator vehicle. With this test they're probably just aiming to test the aerodynamics and actual performance of their scramjet. Using Israeli hypersonic wind tunnels as well with no domestic supercomputers to assist with the program, it may take decades longer to weaponise this than it took China which was around 10 years - between rumours of HGV initial tests of smaller models in 2005ish to 2014 US confirmed flight tests of full scale HGV.
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Actually it should be said that there is no way to be sure what the HGV shown in the October 2019 parade truly represents. English literature supports the idea that the vehicle is the DF-ZF which is the same as the Wu-14, essentially the kinetic warhead or payload itself. The one shown in October has a cover on its front end. It is clearly hiding the actual shape of the nose, possibly even an intake. The nozzles near its tail are quite likely reaction control systems usually useful for exo atmospheric control. Who knows. It is certainly a HUGE vehicle and the largest HGV shown apart from the Xiamen University HGV.
I am more inclined to believe India is trying to develop a Zircon like missile, scramjet powered, smaller speed and payload, possibly using combination of waveriding and aerodynamic surfaces for control. It certainly looks more like their HSTDV models.
I am more inclined to believe India is trying to develop a Zircon like missile, scramjet powered, smaller speed and payload, possibly using combination of waveriding and aerodynamic surfaces for control. It certainly looks more like their HSTDV models.
This should be clarified a bit. With turbofans, it's mostly an engineering and material science problem (manufacturing), where you need turbine blades which can withstand enormous pressure and heat. Then comes the really hard part: replicating this process at an industrial scale with extreme quality standards. However, with hypersonic tech, the main issue is solving physics equations (design), specifically: Fluid Dynamics, commonly known as 'chaos theory', and this is requires massive computing power, a lot of physicists, and expensive testing.
This is why even the countries which have mastered turbofan tech are still struggling with hypersonics in the design stage. Turbofans on the other hand, require an exceptional engineering, materials and industrial base, which hard as it is, is still lower on the ladder.
Lets not overstate the ease of machining hypersonic intakes...
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There's also the matter of heat management.
Precisely! The physics of turbulence is at most a totally "proprietary" or state kept secret IFF there have been developments. For everything close to that, there's a lot of supercomputing power to optimise every geometry of every detail.
India should really be commended on testing a HGV for sure. It's an impressive feat achieved by very few countries. However, the bhakts talking about it like it's a serviceable weapon already is really at least a decade too early. More likely 2 or 3 decade if ever. The engineers will understand.
The challenge with HGV is design and the physics. Having huge budgets, armies of incredible engineers, and all the supercomputing and hypersonic wind tunnel access you want, only help make development possible. India may throw huge budgets at the project and have armies of talented engineers but they do not have access to decent supercomputers. Their domestic hypersonic wind tunnel is still in design phase and just moved beyond planning. Israel's hyersonic tunnel access may be granted but it's not going to be as convenient as doing everything at home. I'm sure they can overcome all this with the right organisation and attitude though. China's overcome much worse with much less.
Turbofans is a mix of experience, experimentation, and design/physics mastery. More demanding overall than hypersonics I think.
Still something well within the means of many, including India. Better designs and shaping however, that's a bit harder. This is where HGVs are easier than turbofans - materials and fabrication technology vs shaping/design.
Well India's future military budget is not looking good down the road. They would need to invest huge to see this project through. They have huge problems with the Indian economy to fix first. Unless India chooses to go into a war-economy mode. This would off course spook its neighbours and China.
Could India instead use Russian supercomputers, wind tunnels, and labs? Russia is historically very generous to India. Maybe do another Brahmos-like joint project? Only this time with the Zircon missile as the template design. That would dramatically speed up India's hypersonic weapons development.