KARI 에서 개발 중인 Scramjet 기반 대공요격시스템...

 

한국항공우주연구원 (KARI) 이 Scarmjet 엔진을 기반으로 하는 근거리 대공요격시스템을 개발 중이라는

AW&ST 기사를 소개 합니다.

 

1월 4일부터 7일까지 美 남부 Florida 州 Orlando 에서 열린 [49th AIAA Aerospace Sciences Meeting

including the New Horizons Forum and Aerospace Exposition] 에서 KARI 연구원들과 KAIST 교수들

이 공동으로 발표한 내용 입니다.

 

발표 내용에 따르면, 2단 Scramjet 엔진을 채용하여 Mach 4 의 속도로 대공 목표물을 타격하는 개념이라

합니다. 현재까지 탄두중량 (payload) 은 약 225 kg 에, 유효거리 500 km 에 이르는 2단 추진체를 개발한

상태이며, 1단 추진체의 길이는 약 3.59 m, Kerosene 연료를 사용하는 2단 Scramjet 엔진 추진체는 길이

7.55 m, 직경 508 mm 정도라고 합니다.

 

또한 전체 추진체의 최대이륙중량 (MTOW) 은 2.1 톤에 이르며, 최대고도 17 km, 유효거리 500 km 까지

8분만에 도달할 수 있다는 연구 내용이며, 이러한 연구 내용을 바탕으로 근거리 대공요격시스템으로의

응용이 충분히 가능하다는 내용 입니다.

 

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Scramjet Scramble

Quick-reaction scramjet interceptor concept outlined by South Korean researchers

Aviation Week & Space Technology, 01/17/2011

Author : Guy Norris

 

 

A ground-launched, two-stage Mach 4 scramjet that can intercept incoming targets traveling at supersonic speed could be developed with existing technology, says a team from the Korea Aerospace Research Institute (KARI), South Korea’s space agency.

 

To date, most supersonic combustion ramjet projects have focused on hypersonic strike weapons, reconnaissance platforms or access to space as part of a combined cycle propulsion system. However, South Korean researchers believe that a kerosene-fueled scramjet, limited to a speed of Mach 4, is feasible for relatively short-range air defense.

 

Speaking at the American Institute of Aeronautics and Astronautics aerospace sciences meeting here, KARI researcher Inyoung Yang says the decision to aim for a slower design speed of Mach 4, rather than more typical scramjet hypersonic speeds above Mach 5, is driven by simpler operational requirements and the use of kerosene as a fuel in place of more energetic hydrogen.

 

“A liquid fuel like kerosene should be used for real applications, but issues with mixing, flame-holding and ignition delays can be reduced with slower-speed flight. So even though the specific impulse [Isp] may be lower, it would not be a problem if only developed for short range,” says Yang.

 

Designed to carry a 500-lb payload over ranges up to 300 mi., the scramjet would be ground-launched on a solid rocket booster to a staging altitude above 50,000 ft. The 11,900-lb.-thrust booster would burn for 54 sec. to boost the scramjet to a transition speed of Mach 3.6-3.7. After separation and combustor inlet ignition, the scramjet will accelerate to Mach 4 and climb to around 55,000 ft. The scramjet, producing up to 1,540 lb. thrust, has an Isp of 1,089 sec. and a maximum burn time of 411 sec.

 

On launch, the vehicle’s gross weight would be around 4,560 lb., three-quarters of which would be made up by the heavier booster element. Occupying the forward 11.8 ft. of the 25-ft.-long stack, the scramjet’s skin would be made of a conventional nickel-chromium super alloy such as Inconel 718. No thermal protection system or special coating would be needed, as the Mach 4 limit would keep maximum skin temperatures below 700K, Yang says.

 

The vehicle is designed to close on inbound targets, notionally believed to be high-speed cruise missiles, which are “assumed” to be traveling at Mach 2.5. To intercept at this speed, the scramjet seeker must acquire the target at a distance of 34 mi., or 30 sec. before impact. Yang provides few details about the seeker or en route and end-game guidance system, other than making references to possible use of GPS-based devices. Given the vehicle’s maximum lateral acceleration limit of less than 4g and turn radius of more than 22 mi., the design assumes the targets remain on relatively predictable trajectories.

 

“Our investigations show it will operate over the whole envelope but with very little margin. This vehicle is feasible, and the development of such a scramjet becomes easier with lower flight speeds for favorable fuel-mixing and flame-holding,” Yang says. Given the lower total pressures and thrust levels involved, the team also says basic engine testing will also be easier. “We think this can be developed with existing technology,” he adds.

 

KARI’s concept builds on initial tests of its S1 scramjet, first tested in a shock tunnel in 2007. Configured with a two-dimensional double-wedge ramp intake, notched cowl and cavity flame-holder combustor, the model demonstrated supersonic combustion and has been followed by an improved S2 version. S2 intake, combustor and scramjet engine models were tested at the Japan Aerospace Exploration Agency’s Kakuda Space Propulsion Center in 2008 and 2009.