Igniting Hypersonics

Enabling missiles that travel 600 miles in 10 minutes or less

5 Ratings

Imagine you are monitoring satellite images and observe hostile forces begin setting up a mobile missile launch site. With current weapons systems, you know that the missile site will be used and then dismantled before a retaliatory strike can be delivered. However, with a hypersonic missile, the strike can be called in and delivered before the missile site is moved so the launch system is destroyed and cannot be used again.

THE CHALLENGE

Scramjets—aircraft engines that fly at hypersonic speeds—are needed to power rapid response time missiles before a hostile launch site can be dismantled or moved. Deploying these missiles is a challenge. They need to be launched from a mobile platform and use a rocket booster to reach altitude and velocity before the scramjet would take over. Igniting a hydrocarbon fueled scramjet is like trying to light a match in a hurricane. Our N2O based system does just that.

WHY IT MATTERS

Hypersonic engines require a lightweight, reliable and robust ignition system due to the high altitude and low temperature operating conditions. Current ignition systems being investigated do not reliably ignite hydrocarbon-fueled hypersonic engines. Without a reliable ignition system the US Air Force will be unable to advance new high speed strike weapon capabilities and potentially be at risk of losing air superiority. Currently, hydrocarbon-fueled scramjets are ignited using a more reactive fuel such as ethylene and then the engine transitions over to JP-7 fuel. The transition from ethylene to JP-7 at start up is unreliable and can frequently cause flame out of the engine. In addition, storing compressed ethylene on board is hazardous and adds a large amount of weight to the system reducing the payload capability.

THE SOLUTION

Reaction Systems, Inc. is working with AFRL to develop our ignition system to reliably ignite ground test engines, working toward the goal of flight demonstrations and ultimately manufacturing ignition systems for new high speed strike weapons. Based on our background and knowledge of catalysts, reactor design and kinetic modeling we were able to generate a concept of decomposing nitrous oxide into a stream of hot oxygen and nitrogen that can be used to reliably ignite a scramjet engine.

"If this Phase III project is successful, our ignition system will be procured by the Air Force for use on upper stage scramjets. This will represent a significant revenue sstream for Reaction System" — David Wickham

HOW IT WORKS

The most efficient way to generate a powerful ignition source is to take advantage of the chemical energy contained in a reactive compound. For example, nitrous oxide will undergo a reaction to form a very hot (2500°F) mixture of 33% oxygen and 66% nitrogen. Simply mixing this gas with a fraction of the main fuel flow would produce a flame with enough energy to ignite the main combustor. Unfortunately, nitrous oxide is a relatively stable compound and the reaction that produces the hot mixture of oxygen and nitrogen will not take place unless a catalyst is present. The challenge with this approach is that traditional catalysts cannot withstand 2500°F without losing their activity very rapidly. However, Reaction Systems has developed thermally stable catalysts that have high initial activity and are more resistant to thermal deactivation than conventional catalysts. The Reaction Systems ignition system is a custom catalytic heat exchanger/reactor that converts nitrous oxide into a hot mixture of oxygen and nitrogen. The system then mixes the hot oxygen and nitrogen from the reactor with JP-7 jet fuel that produces a pilot ignition flame. The JP-7/nitrous oxide-fueled pilot torch is then directed into the flame holding cavity of a scramjet engine during start up.

IMPACT FOR THE FUTURE

A reliable ignition system for hypersonic engines will enable the US Air Force to maintain air superiority by advancing high speed strike weapon capability. Air superiority will deter many conflicts from occurring decreasing the number of servicemen lost.

Continued success of the development of our ignition technology has resulted in a Phase III contract award from AFRL. If this Phase III project is successful, our ignition system will be procured by the Air Force for use on upper stage scramjets. This will represent a significant revenue stream for Reaction Systems

The ignition system enables the US Air Force to maintain a sizable weapons superiority over other potentially hostile and danerous nations.

The technology we developed to mount the catalyst in thin layers on the wall of a reactor led to a substantial commercial project in which a local company contracted us to carry out tests using catalyst coated in thin layers on the walls of a heat exchanger. This project also led to the development of technology to fabricate custom high temperature choked flow venturis (CFVs), which are needed to control the pressure in the N2O decomposition reactor.

It has been tremendously rewarding for me to see the project transition from its initial conception all the way to the scramjet ignition demonstration. — Bradley Hitch, Chief Engineer at Reaction Systems, Inc.

Reaction Systems Inc.

rxnsys.com

Golden Colorado

Reaction Systems, Inc. was formed in May 2005 to develop leading edge technologies. Our goal is to invent new products or processes and turn them into real commercial products. We conduct cutting-edge, high quality research, secure patents on our ideas, and cultivate commercial partnerships.

David Wickham David Wickham

David Wickham

President

Bradley Hitch Bradley Hitch

Bradley Hitch

Chief Engineer

Jeffrey Engel Jeffrey Engel

Jeffrey Engel

Chief Operating Officer

TOPIC TITLE:

Catalytic N2O Decomposition for Piloted Scramjet Ignition

TOPIC NUMBER:

AF083-121

CONTRACT NUMBER:

Phase I Contract No. FA8650-09-M-2956 Phase II Contract No. FA8650-10-C-2097

For more exciting Air Force launch stories, visit launchstories.org

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