Ramjet vs scramjet

By using our site, you acknowledge that you have read and understand our Cookie PolicyPrivacy Policyand our Terms of Service. Aviation Stack Exchange is a question and answer site for aircraft pilots, mechanics, and enthusiasts. It only takes a minute to sign up. Are there any planes that have ramjet or scramjet engines? If so, how did they reach the required mach speed for the engines to start functioning?

There's only a couple flying examples. By far the most [publicly] successful vehicles have been the XA and the X Both were fully controllable, independent flight vehicles rather than just engines hanging from rockets that produced net thrust. Credit: NASA. Credit: USAF. HCV would have been able to carry a few thousands pounds of payload eg bombs, flight test equipment, cameras very quickly across great distances. It's meant to fly completely under its own power using TBCC, taking off with turbines and transitioning to ramjet and finally scramjet operation.

A key innovation was bridging the speed gap between where turbojets stop working well and where ramjets start working well, but LM declined to elaborate how they achieved that.

What is the difference between scramjet and ramjet engines?

Their design apparently builds upon their work on the Falcon program see above. They said they'd fly a single-engined demo before moving to the twin-engined, full-scale vehicle. Credit: Lockheed Martin. Both were large tonnes MTOWhypersonic, intercontinental vehicles.

X NASP. Credit: Chad Slattery. Source: FAS. It was a very innovative design Machno canopy, periscope, crew capsule, huge radar, and internal bays for 6 large missiles, precursors to the AIM but never flew. Source with lots of great background. Credit: Boeing. Credit: DR Kirk. Credit: USN. Some are antiship missiles various trajectoriessome are SAMs, and some are air to air missiles. All were rocket-boosted before the ramjet took over.Scramjet Engine is making headlines these days.

But what is a Scramjet Engine? This is a variant of a ramjet jet engine in which combustion takes place in supersonic airflow. As Scramjet is essentially a Ramjet with variations, it would be easy if we start our learning process from Ramjet.

ramjet vs scramjet

The main difference is that a rocket carries its own supply of oxygen Oxidizer Tank for combustion while a jet engine utilizes oxygen from the atmosphere for combustion.

This makes rocket engine less energy efficient when compared to Jet engines. A jet engine is a machine that converts energy-rich, liquid fuel into a powerful pushing force called thrust. The thrust from one or more engines pushes a plane forward, forcing air past its scientifically shaped wings to create an upward force called lift that powers it into the sky. It increases the velocity of the exhaust gases, thereby powering the vehicle.

All jet engines and gas turbines work in broadly the same way. Hence they all share five key components: an inlet, a compressor, a combustion chamber, and a turbine arranged in exactly that sequence with a driveshaft running through them. Even though they have similarities, jet engines differ in their extra components.

The main types of Jet engines based on how air is compressed in the engine are as below:. Turbo jet engine is an air-breathing jet engine. This is one of the most common types of jet engines. It is still widely used in airplanes. Turbofans differ from the turbojets in the way they have an additional component — a fan. The fan sucks in the air and then further gets compressed and combustion takes place in the burner.

High-speed forward motion is used to compress the air no compressor. Fuel is injected into the combustion chamber where it mixes with the hot compressed air and ignites. The average speed of Ramjet is Mach. But the ramjet efficiency starts to drop when the vehicle reaches hypersonic speeds. Here also, the high-speed forward motion is used to compress the air no compressorbut it is an improvement over the ramjet engine as it efficiently operates at hypersonic speeds and allows supersonic combustion.

Speed is greater than 6 Mach Six times the speed of Sound. Type of jet engine where a ramjet transforms into scramjet over Mach range, therefore, it can operate both in subsonic and supersonic combustion modes. India had started the efforts on Scramjet technology long back and we did a ground testing in which validated the design of the engine.

And now, India became the fourth country to claim the successful testing of Scramjet Engine. Russia was the first country who claimed scramjet flight test inand later US and European Space agency also joined the elite group. It is designed to use ramjets and scramjets for thrust. Each of these engines will be used in different stages of the flight wherein scramjets are used at hypersonic speeds.

Air breathing propulsion is a solution for a powered long return cruise flight necessary for reusable launch vehicles. This calls for the faster development of ramjet or scramjet technologies which would help India to execute advanced space missions in future. Also, it will add colors to our much hyped Make In India initiative.Ramjet vs Scramjet. Supersonic and Hypersonic flight are dreams of aeronautical engineers, where flying as many times the speed of sound is a technically difficult endeavor.

Even though supersonic is a realized dream the cost makes it difficult to be used financially. Ramjet and Scramjets are engines using its own speed to compress air and propel the engine. The ramjet engine technology practically applies in many cases ranging from missiles, supersonic aircraft to artillery rounds, while the scramjet engines are still highly experimental. By design, ramjets cannot produce thrust at zero velocity, initially when they are still.

Therefore, the aircrafts require a propulsion system to initiate the movement for compression in the ramjet to undertake. For optimal operation ramjets need velocities around Mach 3 and can operate up to speeds of Mach 6. The operation of the Ramjet is based on the Brayton cycle. The intaken air is compressed using nozzles created in the compression areas, and the flow speed is reduced to subsonic speeds to allow better combustion.

A flame holder ignites the mixture to produce high pressure high velocity gas stream that exits the engine at supersonic speeds. Ramjets can be used for applications requiring a small and simple engine for high speed use, such as Russian Indian stealth BrahMos missiles, and Indian Akash missile uses ramjet technology. They have also been used successfully, though not efficient, as tip jets on helicopter rotors.

The jet engines of legendary Lockheed SR 71 act as ramjets as the aircraft speeds more than the speed of sound.

Advantages of ramjets are independent of oxygen supply and include no rotating parts which makes it easier to manufacture and maintain.

A scramjet Supersonic Combustion RAMjet is a variant of a ramjet in which combustion takes place when the airflow is supersonic. As in ramjets, scramjets also compress the incoming air before combustion using the speed of the vehicle. However, ramjets decelerate the airflow to subsonic speeds within the engine prior to combustion, though airflow in a scramjet is supersonic throughout the entire engine.

Like ramjet, scramjets have no moving parts inside the engines and inherit all the fundamental requirements like primary propulsion system to accelerate them to supersonic speeds. While scramjets are conceptually simple in design and construction, actual implementation is limited by extreme engineering challenges. The aerodynamic drag at Hypersonic flight within the atmosphere is immense, and temperatures found on the aircraft and the engine is much greater than the temperature surrounding the air; hence requiring new materials to endure the temperatures.

Maintaining combustion in the supersonic flow poses additional challenges because, within milliseconds of time, the fuel must be injected, mixed, ignited, and burned. In addition to the advantages of common ramjets, scramjets have a higher specific impulse change in momentum per unit of propellant than conventional jet engines.

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Ramjets produce specific impulse between and seconds, while a rocket only provides seconds or less. Because scramjets have the high theoretical performance, they have been suggested as the power plant for next generation orbital vehicles and the NASA conducts extensive research in the scramjet technology arena.

However, the fastest practically obtained speed is 9. Coming from Engineering cum Human Resource Development background, has over 10 years experience in content developmet and management.The Scramjet is distinctive by its rounded and sleek profile, featuring a trident-like front end, where the edges on either side house the headlights.

The wheel arches appear to be wider than the greenhouse area and have a concave shape for the wheels. Two small fins can be seen directly behind the seats, over the rounded portions of the rear section. The rear end has a similar curved profile to the front end, where the outer concave portions house the tail lights and the edges on either side house the exhausts, which double as rocket boosters.

The Scramjet's aerodynamic design allows for good acceleration and top speed, as well as decent handling and braking. Its suspension is low due to its wheels having negative camberoften struggling to sort small barriers, but it is slightly compensated by the front end having a sloped profile, sorting out curbs and small bumps normally.

The Scramjet has 5 Advanced Flags activated [1]including the 4 flags introduced in the Southern San Andreas Super Sport Series update, with only the first three having known purposes. They are as follows:. The Scramjet is powered by a front engine, coupled to a 6-speed gearbox in a rear wheel drive layout. Its engine sound is similar to that of the XA Protection-wise, the Scramjet offers little to no resistence to explosive damage, as one direct hit by a Homing Missile is able to destroy it.

Furthermore, due to its open-top design, the occupants are also prone to sustained gunfire.

ramjet vs scramjet

Inadvisable to take this vehicle to heavy shootout scenes. Both abilities can be used simultaneously, making the Scramjet a great vehicle for shortcuts and evading most enemies.

However, it requires practice, as the car tends to lean forward when using the booster mid-air. This also requires awareness of the environment, as the car may accidentally end up getting stuck or even sinking on water. The vehicle comes with a set of driver-operated weapons located on the concave portions of the front end, next to the headlights:.

The driver also has access to their arsenal for drive-bysbeing useful against targets that are away of the vehicle's front or in situations where lighter weaponry is vital i. The Scramjet can only be modified at a vehicle workshop inside a Mobile Operations Center or an Avenger. Rear quarter view. Fandom may earn an affiliate commission on sales made from links on this page. Sign In Don't have an account? Start a Wiki. For a complete list of the features of the "enhanced" version of Grand Theft Auto Vplease see here.

Lockheed unveils SR-72 hypersonic Mach 6 scramjet spy plane

No one thought we had any need to jolt a hyper-stylized retro speedster thirty feet into the air and turbo boost it into the side of the nearest high-rise. But once it happened, and we saw the kind of potential it unleashed, there was no going back. This one's for the dreamers. Contents [ show ]. Dashboard View. Categories :. Stream the best stories.I was just thinking - can scramjets scale up better than rockets can?

Yes, I know everyone on the forum overwhelmingly prefers rockets to space and getting clear of the pesky atmosphere as quickly as possible. Since we have to face the tyranny of the rocket equation, how much benefit do scramjets offer in trading off mass fraction constraints against the thermal load of hypersonic flight? I'm supposing that a vehicle's mass generally correlates to its volume, and its hypersonic thermal load correlates to its surface area and velocity.

The scramjet then has the better mass-fraction because it doesn't need onboard oxidizer mass, but the tradeoff is the hypersonic thermal load. As our scramjet scales up and gets bigger, isn't there a sort of cube-square divergence that occurs? Whereas the mass-correlated volume of the vehicle goes up with a cube power, the relative surface area would only go up with a square power.

So as you get bigger and more massive, the related thermal load isn't growing as much compared to your mass. Doesn't that mean that a bigger scramjet is more advantageous over a smaller scramjet?

Who has the greater advantage, as you go to large scales? Rocket Science likes this. First flight to Mars by end of Forward looking statements. I'm starting to get suspicious of the "scamjets" meme. Sure, the current state of the technology is uninspiring, but the same could be said of nuclear fusion. How much effort have we actually put into this field? Liked: Likes Given: It's entirely possible that the lack of progress for dollar value is due to standard indefensible defence industry largess which is endemic in every defence industry on planet Earth, but scramjet-to-orbit or even scramjet as a stage in a horizontal launch vehicle looks extremely difficult without either revolutionary engineering improvements or significant atmospheric composition changes.

I'm sure a system integrating scramjets could be finessed to work eventually, but it'd take huge continuous investment to do so and even then you'd end up with a system less efficient than VLVs.

It's funny nuclear fusion has been brought up here, since nuclear fusion actually has produced more results for less money albeit, still a huge amount over a smaller timescale. Scramjets are revolutionary jet engines that push what an airbreather can do within Earth's atmosphere, and enable some incredibly high mach numbers.

It just won't get you to orbital speeds.Tremendous, Excellent information.

ramjet vs scramjet

I loved your hard work for this information about rocket engines, Thanks a lot Jet propulsion is the basic physics associated with all the airplanes, jets, missiles and rockets. All these vehicles except rockets run with the help of jet engines which are air breathing engines. However, rockets will not belong to the category of air breathing engines, rather they are self-contained engines.

This page will give you the basic differences between all these engines so that the Mechanical engineer or the Aeronautical engineer in you can identify the basic concepts behind these engines. So fasten your seat belts, let's take off. Before going into the basics of these engines, one must be very thorough with the concept of Mach Number.

It is defined as the ratio velocity of flow to the acoustic velocity Velocity of sound at the given temperature of the flow field. The given condition of the flow field is a very important consideration for Mach Number. The airplanes which we used to travel is below Mach 1 or nearly to Mach 1 and is in the subsonic velocity.

Which means Airplane is traveling at a velocity less than the speed of sound at the altitude temperature where it is flying. So that is all about Mach Numbers. Now let us discuss jet engines. Jet engines are also known as reaction engines because the reaction produced by the engines propels the aircraft or vehicle. They are basically internal combustion engines discharging hot exhaust gases at high velocities that generated thrust. Jet engines produce power by sucking air at the front side and discharging it at the backside, unlike the automobile IC engine which produces power by the reciprocating motion of the piston.

The thrust force is the force which propels all these engines which can be better explained by Newton's third law of motion.

ramjet vs scramjet

Some of the important components of conventional jet engines or a turbojet engine are compressor, combustor, turbine and a nozzle. However, there can be additional elements attached like fans in case of a turbofan engine and propeller in case of a turboprop engine. Pulsejet, Ramjet and Scramjet engines which are modern developments in the field of jet engines which don't require compressor and turbine.Today, 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. Thus, there is a worldwide effort to reduce the launch cost. 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.

Ramjet missile propulsion - the biggest invention since the introduction of the jet engine

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.

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 range, which means it can efficiently operate both in subsonic and supersonic combustor modes. After a smooth countdown of 12 hours, the solid rocket booster carrying the Scramjet Engines lifted off at hrs 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 seconds, the vehicle touched down in the Bay of Bengal, approximately 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.

ATV carrying Scramjet engines weighed kg at lift-off. ATV is a two stage spin stabilised launcher with identical solid motors based on Rohini RH 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. 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. Skip to main content. Search form Search.