Engineers at ISRO are gearing up to test the scramjet engine developed in-house to power the Reusable Launch Vehicle (RLV) due to undergo the first experimental flight shortly.The scramjet engine which uses air breathing propulsion technology for hypersonic flight is scheduled to be test flown in January or February, VSSC Director K. Sivan said here on Friday. Talking to the media on the sidelines of the National Aerospace Manufacturing Seminar (NAMS- 2015) organised by the Society of Aerospace Manufacturing Engineers, he said the scramjet engine would be strapped to a two-stage Rohini sounding rocket for the experimental flight lasting seven seconds. It will be released at a height of 70 km and ignited during the coasting phase.
The basic design of a scramjet has already been evolved.A test launch of the engine aboard a sounding rocket, which will achieve a flight regime of up to Mach 8, will take place some place in June at SHAR, Dr. Sivan said.
"We will soon be testing - may be this June - our air breathing engine fitted to a sounding rocket," Mr Sivan said.
After successfully testing a technology demonstrator of a reusable launch vehicle, Indian Space Research Organisation (ISRO) is planning to test an air-breathing propulsion system, which aims to capitalise on the oxygen in the atmosphere instead of liquefied oxygen while in flight.“The mission to test the technology would be launched either in the last week of June or early July from Satish Dhawan Space Centre at Sriharikota. The mission would be on a sounding rocket,” K. Sivan, Director of the Thiruvananthapuram-based Vikram Sarabhai Space Centre told The Hindu.
The new propulsion system, once mastered, would complement ISRO’s aim to develop a reusable launch vehicle, which would have longer flight duration. The system, involving the scramjet engine, would become crucial while sending up the spacecraft.
According to ISRO, the Dual Mode Ramjet (DMRJ), the ramjet-scramjet combination, “is currently under development, which will operate during the crucial Mach 3 to Mach 9 ascend flight of the launch vehicle.”
I want to ask about this whole idea of collecting LOX on the way up - I'm not sure if ISRO or DRDO are the originators of this idea or if it came from somewhere else, but it sounds weird/absurd to me.To me, it sound like sticking a windmill on the front of your car, and then claiming it will generate power while you drive, and using it to further accelerate your car.One Indian technical paper talks about "liquefaction drag" which requires fuel consumption to offset it. But so if you're getting a bit more drag from collecting LOX and having to spend more fuel to compensate, is there a net benefit from accumulating oxygen for later use in getting the rest of the way to orbit?From what I remember way back on that AVATAR SSTO study, they felt the LOX collection on the way up was some kind of key enabler to make SSTO feasible. They felt there was some narrow operating window within which this could all work.Anybody know anything on this?
But who said anything about "accumulating LOX"? Scramjet uses atmospheric oxygen as oxidizer to operate. There's no liquid O2 up above.
Quote from: ss1_3 on 05/27/2016 10:05 amBut who said anything about "accumulating LOX"? Scramjet uses atmospheric oxygen as oxidizer to operate. There's no liquid O2 up above.I'm not talking about your regular scramjet that only immediately burns the oxygen as it sucks it in. I'm talking about this idea (that's been discussed in Indian circles at least) that you can additionally also even collect some of the oxygen and store it for later, for when you rocket the rest of the way to orbit. Is that plausible, or is it too weird?
In all the slides above and the referenced news articles, I don't see LOX being talked about. Can you cite any paper or news links where they are talking about "collection"? How'd that even qualify as scramjet or ramjet?
The idea is to develop a spaceplane vehicle that can take off from conventional airfields. Its liquid air cycle engine would collect air in the atmosphere on the way up, liquefy it, separate oxygen and store it on board for subsequent flight beyond the atmosphere. ...During this cruising phase, an on-board system would collect air from the atmosphere, from which liquid oxygen would be separated and stored and used to burn the stored hydrogen in the final flight phase to attain orbit.
You really need to read up on Skylon and the SABRE... http://www.reactionengines.co.uk/
Quote from: Rocket Science on 05/27/2016 04:06 pmYou really need to read up on Skylon and the SABRE... http://www.reactionengines.co.uk/Yeah, sure I've read about Skylon, SABRE and its pre-cooler technology - watched the documentary and all that - but I never realized it was collecting oxygen for later use. I thought it was just burning the air immediately, and that it had a separate onboard LOX supply that was pre-loaded. I thought the pre-cooler was just to keep parts from melting. Ah, so now I know better.
Unlike conventional rockets, Air Breathing Propulsion System makes use of atmospheric oxygen for combustion thus resulting in substantial improvement in payload fraction and reduction in overall cost. Though the developmental activities towards dual mode ramjet engines and their associated technologies have been initiated, the present focus is on development of scramjet engine and flight testing the same in a cost effective method using Advanced Technology Vehicle (ATV).The major highlights of development in this regard in the year include realisation of Avionics module and Energiser for Pilot Flame Ignition Unit, Qualification of Silicon Carbide coated Carbon/Carbon leading edges through hot tests at 6 MW Plasma Wind Tunnel Facility and commencement of Integration activities on scramjet engine frame and engine flow duct.Rapid expulsion tests using gaseous hydrogen modules for the Titanium lined Carbon wrapped Gaseous Hydrogen bottles to be housed in Fuel Storage and Feed System was successfully conducted at IPRC, Mahendragiri. Acoustic characterisation test of Engine and Fuel Feed System as mounted to sustainer vehicle configuration was carried outat NAL, Bengaluru.Assembly and Integration of Air Breathing propulsion modules, namely. Scramjet Engines and Fuel Feed System for ATV-D02 flight, are in progress. The demonstration flight of advanced Technology Vehicle carrying active scramjet engine flight is targeted in 2016.
Advanced Technology Vehicle and Sounding Rocket Project (ATVP)Advanced Technology Vehicle (ATV) has the unique capability to carry a payload of 200-400 kg up to an altitude of 800 km. Ascent of ATV in a direct vertical profile is an excellent platform for studies related to upper atmosphere and short duration transient phenomena in the atmosphere. ATV provides a cost effective platform for the study of micro-gravity providing a dwell time of 10 minutes at levels better than 100 micro-g, which can be used for microgravity experiments in fluid physics, combustion research, material sciences, biology and also to perform precursor experiments for launch vehicles, satellites and human spaceflight mission.Advanced Technology Vehicle (ATV-D02) flight: ATV-D02 is the sounding rocket identified for carrying the twin scramjet air breathing engines for demonstrating supersonic combustion experiment scheduled during first quarter of 2016. The major activities completed towards this mission is Acoustic Test of ATV-D02 sustainer vehicle configuration at National Aerospace Laboratories (NAL), Bengaluru, booster motor casting and spin test of Advanced Telemetry System with Sequencer. The Sustainer motor is ready for casting and the Aero dynamic and structural load studies have been completed.
Was the last sentence sarcasm?
Yes, melting of parts is an big issue, but so is the physics of the combustion. You have to get the right flow rate into the combustion chamber, so how far up the temperature/pressure curve would the mass flow rate out from the turbocompressor have to operate at if the inlet temperature was already at stagnation temperature? I don't think it was suggested anywhere Skylon was collecting O2 for later use. My understanding of Rocket Science's first reference to Skylon was that if ISRO wants to collect significant amount of O2 for use, it will face the same technical challenge as Skylon, that being the cooling of the air stream before you can do anything useful with it. Skylon does not store the air, it burns it as it passes through. If ISRO wants to store up LOX, you have to first make an equivalent pre-cooler to Skylon, then you probably have to add another compression & expansion step to reject even more heat from the working fluid before you collect your first drop of LOX. So from a technical standpoint, sure you can make LOX from air, but you are talking about making tons of it in a matter of 60-90 seconds of your flight regime that you are low enough in the atmosphere to even have access to enough air to make a difference. So what would the trades be for all the additional equipment ( compressor, expansion chamber+heat exchangers, etc. vs. just building a sufficiently sized LOX tank that you load during ground ops?
There are also so-called liquid air cycle engines (LACE) that would liquify air and store that for use by rocket engines to use once the air was too thin for the scramjet to work well:https://en.m.wikipedia.org/wiki/Liquid_air_cycle_engineThe link to the comments by Henry Spencer discussing just how difficult it would be to actually get this to work is worth following:http://www.islandone.org/Propulsion/SCRAM-Spencer1.html
So from a technical standpoint, sure you can make LOX from air, but you are talking about making tons of it in a matter of 60-90 seconds of your flight regime that you are low enough in the atmosphere to even have access to enough air to make a difference. So what would the trades be for all the additional equipment ( compressor, expansion chamber+heat exchangers, etc. vs. just building a sufficiently sized LOX tank that you load during ground ops?
If your fuel was LH2, which is substantially lighter than LOX, then you're burning it off during the upper cruise phase to get more LOX, in order to save on having to take off with that LOX on the ground. So the question is, could it be worth it?
If the vehicle was itself a TSTO rather than SSTO, maybe the LOX-collection could serve as a form of cross-feed to an upper stage? (Like the way FalconHeavy's side-cores cross-feed propellant to the central core which keeps traveling onward without them)
Like I said, the idea seems weird to me, but I was wondering if the hard numbers would justify it.
So that was interesting - storing the energy from frictional heating in chemical bonds by having the heating modify the fuel. Never heard of that before.
The test flight of the indigenously-developed scramjet engine is scheduled to take place from the Satish Dhawan Space Centre at Sriharikota sometime in July.<snip>“The vehicle has been characterised and is being fabricated at the VSSC and the ISRO Propulsion Complex, Mahendragiri,” VSSC Director K.Sivan told The Hindu<snip>The air-breathing engine will be released at a height of 70 km and ignited during the coasting phase. Apart from the hypersonic ignition at Mach 6, ISRO hopes to sustain the combustion for 5 seconds.“The test is also expected to help us achieve good thrust value with the scramjet engine,” Dr. Sivan said.
ISRO ready for air-breathing propulsion experimentThe Indian Space Research Organisation (ISRO) is looking forward to performing “an experiment” before July-end aboard its RH-560 rocket fitted with a supersonic combustion ramjet (scramjet) engine for demonstrating air-breathing propulsion technology.At three tonnes, the two-stage RH-560, christened Advanced Technology Vehicle (ATV), is the heaviest sounding rocket built by the ISRO. It will lift off from a launch pad built for sounding rockets at Sriharikota. The Vikram Sarabhai Space Centre (VSSC), Thiruvananthapuram, has developed the engine.“The ignition of the scramjet engine in flight and holding the flame steadily for five seconds” — when the air from the atmosphere is being rammed into the engine through an inlet at a supersonic speed of six Mach — “is the objective of the experiment,” said VSSC Director K. Sivan.<snip>The entire mission will last 260 seconds.
A1571/16 - ADVANCED TECHNOLOGY VEHICLE (ATV-D02)SOUNDING ROCKET LAUNCH FM SHAR RANGE,SRIHARIKOTA WILL TAKE PLACE AS PER FLW DETAILS. LAUNCH PAD COORD : 13 41 44 N 080 14 05 E. NO FLT IS PERMITTED OVER THE DNG ZONE. I)DANGER ZONE- 1 IS A CIRCLE OF 10NM AROUND THE LAUNCHER II)DANGER ZONE-2 IS A SECTOR BTN RADII OF 50NM AND 250NM FM THE LAUNCH PAD AND BTN AZIMUTH ANGLES 080 DEG AND 120 DEG FM TRUE NORTH ROUTES AFFECTED IN CHENNAI FIR ARE: W20,A465,N571,P761,P574,B466,L518,Q10,Q11,V3,V4,V6,V8,V9,V11,Q23 AND Q24 CLOSURE/ALTERNATE ROUTINGS: A) W20 NOT AVBL BTN MMV VOR AND BODEL ALTN ROUTE: MMV VOR-TR319/139DEG-53NM-TTP VOR-TR357/177DEG-81NM-BODEL -W20 (BIDIRECTIONAL) B) A465 NOT AVBL BTN MMV VOR AND DOCKET ALTN ROUTE:MMV VOR-TR319/139DEG-DIST 53NM-TTP VOR-VT034/214 DEG -DIST 53NM-POINT 'A'(142225N 0800303E)-TR055/235DEG-126NM-DOCKET-A465 (BIDIRECTIONAL) END PART 1 OF 2. BTN 0130-0530, 28 JUL 01:30 2016 UNTIL 11 AUG 05:30 2016. CREATED: 22 JUL 08:15 2016
And here is NOTAM
Quote from: Ohsin on 07/23/2016 06:18 pmAnd here is NOTAMSee also the Indian sub-orbital launches thread where this NOTAM first appeared
ISRO’s Scramjet Engine Technology Demonstrator Successfully Flight TestedToday, satellites are launched into orbit by multi-staged satellite launch vehicles that can be used only once (expendable). These launch vehicles carry oxidiser along with the fuel for combustion to produce thrust. Launch vehicles designed for one time use are expensive and their efficiency is low because they can carry only 2-4% of their lift-off mass to orbit. Thus, there is a worldwide effort to reduce the launch cost.Nearly 70 % of the propellant (fuel-oxidiser combination) carried by today’s launch vehicles consists of oxidiser. Therefore, the next generation launch vehicles must use a propulsion system which can utilise the atmospheric oxygen during their flight through the atmosphere which will considerably reduce the total propellant required to place a satellite in orbit.Also, if those vehicles are made re-usable, the cost of launching satellites will further come down significantly. Thus, the future re-usable launch vehicle concept along with air-breathing propulsion is an exciting candidate offering routine access to space at far lower cost.Considering the strategic nature of air-breathing technology which has the potential to bring a significant shift in the launch vehicle design, worldwide efforts are on to develop the technology for air breathing engines. Ramjet, Scramjet and Dual Mode Ramjet (DMRJ) are the three concepts of air-breathing engines which are being developed by various space agencies. A ramjet is a form of air-breathing jet engine that uses the vehicle’s forward motion to compress incoming air for combustion without a rotating compressor. Fuel is injected in the combustion chamber where it mixes with the hot compressed air and ignites. A ramjet-powered vehicle requires an assisted take-off like a rocket assist to accelerate it to a speed where it begins to produce thrust. Ramjets work most efficiently at supersonic speeds around Mach 3 (three times the speed of sound) and can operate up to speeds of Mach 6. However, the ramjet efficiency starts to drop when the vehicle reaches hypersonic speeds.A scramjet engine is an improvement over the ramjet engine as it efficiently operates at hypersonic speeds and allows supersonic combustion. Thus it is known as Supersonic Combustion Ramjet, or Scramjet.A dual mode ramjet (DMRJ) is a type of jet engine where a ramjet transforms into scramjet over Mach 4-8 range, which means it can efficiently operate both in subsonic and supersonic combustor modes. An important development in ISRO’s Air Breathing Propulsion Project (ABPP) occurred on August 28, 2016, which was the successful flight testing of its Scramjet.This first experimental mission of ISRO’s Scramjet Engine towards the realisation of an Air Breathing Propulsion System was successfully conducted from Satish Dhawan Space Centre SHAR, Sriharikota.After a smooth countdown of 12 hours, the solid rocket booster carrying the Scramjet Engines lifted off at 0600 hrs (6:00 am) IST. The important flight events, namely, burn out of booster rocket stage, ignition of second stage solid rocket, functioning of Scramjet engines for 5 seconds followed by burn out of the second stage took place exactly as planned.After a flight of about 300 seconds, the vehicle touched down in the Bay of Bengal, approximately 320 km from Sriharikota. The vehicle was successfully tracked during its flight from the ground stations at Sriharikota.With this flight, critical technologies such as ignition of air breathing engines at supersonic speed, holding the flame at supersonic speed, air intake mechanism and fuel injection systems have been successfully demonstrated. The Scramjet engine designed by ISRO uses Hydrogen as fuel and the Oxygen from the atmospheric air as the oxidiser. The August 28 test was the maiden short duration experimental test of ISRO’s Scramjet engine with a hypersonic flight at Mach 6. ISRO’s Advanced Technology Vehicle (ATV), which is an advanced sounding rocket, was the solid rocket booster used for this recent test of Scramjet engines at supersonic conditions. ATV carrying Scramjet engines weighed 3277 kg at lift-off.ATV is a two stage spin stabilised launcher with identical solid motors (based on Rohini RH560 sounding rocket) as the first as well as the second stage (booster and sustainer). The twin Scramjet engines were mounted on the back of the second stage. Once the second stage reached the desired conditions for engine “Start-up”, necessary actions were initiated to ignite the Scramjet engines and they functioned for about 5 seconds. ATV flight operations were based on a pre-programmed sequence.Some of the technological challenges handled by ISRO during the development of Scramjet engine include the design and development of Hypersonic engine air intake, the supersonic combustor, development of materials withstanding very high temperatures, computational tools to simulate hypersonic flow, ensuring performance and operability of the engine across a wide range of flight speeds, proper thermal management and ground testing of the engines.India is the fourth country to demonstrate the flight testing of a Scramjet Engine.
IIT-Kanpur, senior professor of aerospace engineering department, Prof DP Mishra was equally delighted for the fact that eight years ago he had worked on the design of the atomizer which is an essential component of scramjet engine.After successful testing of the atomizer by Prof Mishra in his combustion lab in IIT-Kanpur, it was later handed over to ISRO for further use. It was in the year 2006 that Vikram Sarabhai Space Centre division of ISRO had approached Prof Mishra for developing the design and later conducting successful test of the atomizer."The project took two years to complete as it was started on February 14, 2006 and completed on February 13, 2008. It was between this period that we had been successful in designing a new atomizer and further conducted its successful lab tests. Thereafter, the atomizer was handed over to ISRO", informed Prof Mishra while talking to TOI.Explaining an atomizer, Prof Mishra said, "It forms an important component of scramjet engine to provide it fuel for combustion purpose. But the atomizer designed by us was an advanced one, different from the traditional atomizers used in aeroplanes.
Why does it take do long for the test to happen after technologies were developed? Is it budgetary constraints?
Indian Space Research Organisation chairman S Somanath on Thursday said there will be an announcement soon about the space agency's testing facility with regard to the hypersonic air breathing vehicle 'Hava'. The space scientist, however, emphasises that ISRO was not focused on air breathing technology because it wants to deal more with space.
'HAVA' stands for Hypersonic Air Breathing Vehicle with Air Integration System. Replying to a query on the progress made on air breathing technology, Somanath said ISRO is looking at it not as an immediate input for any rocket but as a technology capability.
"ISRO is not much into air breathing technology primarily because we don't want to dwell in air, we want to go to space. But we develop the technology because it is a very high-end technology in terms of capabilities that we have -- in terms of combustion etc. So we are testing the engine.
We are testing in our Mahendragiri facility where we have established a hypersonic test facility," he added.