India Indian Scramjet and Hypersonic Programs

Nilgiri

Experienced member
Moderator
Aviation Specialist
Messages
9,272
Reactions
96 18,816
Nation of residence
Canada
Nation of origin
India
@SavageKing456 I honestly never thought of that idea.....to use longer chain fuel to absorb heat first and get more combustible fuel as byproduct for the combustor itself. ... I didnt know they were that sufficiently endothermic to make difference here at this scale.

In rocketry simply the direct cryogenic temperature is used for cooling where its relevant.
 

Nilgiri

Experienced member
Moderator
Aviation Specialist
Messages
9,272
Reactions
96 18,816
Nation of residence
Canada
Nation of origin
India
Archiving here to maybe discuss/query more over time more conveniently here for any interested:

Any scramjet in todays science + engineering realm poses a significant challenge to overcome. Specifically the various precise local breakdowns in science + engineering when it comes to supersonic combustion (the enthalpy addition specifics in a medium no longer able to handle such conventionally like before).

The greatest driving underlying factor (that nearly all else, including those you mention, stem from) is the actual speed of sound, given what this represents to information flow in a control volume that involves supersonic flow and the resultant intensity/capacity for enthalpy addition to produce work/power.

If air is in subsonic regime, it is essentially always "in communication" with itself as to say what lies up ahead in a flow and let natural optimisation/consequence (w.r.t its own physical limits) establish. Matters we have long observed, studied and employed.

This essentially means we are able to take many matters for granted (that we often dont quite realise) by way of robustly known + broadly applied science and engineering with this intrinsic "self-ability" nature of the working fluid itself when its travelling below the speed of sound.

But this all changes with supersonic flows. The air no longer has the same signalling ability to itself ....say from a fuel nozzle strut dynamic with the flame (and the cascading effects pas that too)....like it would have enjoyed if it was travelling below the speed of sound.

This makes most of the great chasm (in system results and realisation we have accomplished) between a ramjet (which sees only subsonic regime within the combustion process) and a scramjet (which requires supersonic combustion).

i.e we can no longer harness much of what nature did itself (especially in such complete, reliable and near instantaneous way) once we cross the sonic threshold for a medium. This takes new proportions for something like combustion stability and sustainability (which involves two material interaction with pressure and heat).

The relative "blindness" (loss of natural medium info-matrix ability) past this threshold (in especially this combustion objective) is thus something for human understanding and experience in this regime to more slowly bridge and address.

Each thing that could be taken for granted earlier has to be re-understood and re-applied....each cascade of this has to also be checked and re-applied to the feedback loop. Each iteration of this throws up new constraints and challenges that then need more time to solve.

It takes a great deal of time compared to nature simply having it "built in" to do these things like is the case below the sonic threshold, especially for something like combustion.

It is the basic reason why supersonic combustion is only recently being more extensively researched, broached and tested.....compared to the duration we have had supersonic travel more broadly (but were careful to harness natural reliable physics to its maximum by keeping combustion subsonic etc)

Given nature no longer provides this massive intrinsic assistance (in combustion)....a whole new level of substitution for it by way of iterative engineering and detailed scientific enquiry at increasingly higher resolution is the sole approach that can be foreseeably taken.

Given the physical finite limits of air (especially its compressibility), It is only with (yet to be) reliably realised supersonic combustion that (non gravitational) hypersonic flight be achieved (with an internal combustion engine process)....i.e scramjets.

Conventional ramjets are largely bounded to supersonic flight only given hypersonic (entry) air cannot be compressed sufficiently (with say internal shockwaves) and slowed down to subsonic speeds for the combustion process that ramjets employ in the more conventional fashion on offer.

@Anmdt @MisterLike @Cabatli_53 @T-123456 @Test7 @Gessler @Joe Shearer @Paro et al.
 

Gessler

Contributor
Moderator
India Moderator
Messages
799
Reactions
35 1,755
Nation of residence
India
Nation of origin
India
CGI of HSTDV with booster

Fm1-FtTWQAAURWw.jpg


Fm1-IBjWAAAkAKn.jpg
 

Nilgiri

Experienced member
Moderator
Aviation Specialist
Messages
9,272
Reactions
96 18,816
Nation of residence
Canada
Nation of origin
India
In this edition of 'The Defenders' experts share their views on Hypersonic Technology. Recently India tested its own hypersonic technology demonstrator vehicle (HSTDV) powered by a scramjet engine. After this, India became the 4th country in the world to have hypersonic technology. In this episode we discuss how this technology is valuable for both offensive and defensive capabilities.

Anchor- Maroof Raza

Guests:

1.Sudhir Kumar Mishra, Ex Director General, DRDO
2.Lt Gen (Retd.) VK Saxena, Distinguished Fellow, VIF


 

Nilgiri

Experienced member
Moderator
Aviation Specialist
Messages
9,272
Reactions
96 18,816
Nation of residence
Canada
Nation of origin
India
Top Bottom