사각채널 내 수소-공기 혼합기의 DDT에 대한 RANS 기반 수치해석 연구 = Investigating the DDT of H2-Air Mixture in a Rectangular Channel using RANS-Based Numerical Analysis

다국어 초록 (Multilingual Abstract)

In this study, a numerical code based on Reynolds-Averaged Navier-Stokes (RANS) method was developed usingOpenFOAM to investigate the deflagration to detonation transition (DDT) phenomenon in hydrogen-air mixture gas insidea rectangular channel. The channel was modeled with a thickness of 80 mm and a length of 2000 mm. The numericalsimulations were compared with the experimental results and it was found that the developed code qualitatively wellsimulated the transition process from deflagration to detonation. It was also found that the pressure distribution and reactionprogress variables can be useful indicators to understand the instant and location of DDT occurrence. The location of DDTwas found to be at the point where the shock wave and the position of the flame front matched. Furthermore, it wasobserved that the higher the height of the obstacle, the earlier the DDT occurred, but the magnitude of pressure after theDDT did not correlate with the height of the obstacle.

국문 초록 (Abstract)

본 연구에서는 폭연에서 폭굉으로 천이되는 현상(deflagration to detonation transition, DDT)의 전산해석에 적합한reynolds-averaged navier-stokes (RANS) 기반의 OpenFOAM 수치코드를 개발하였다. 개발된 코드를 이용하여 두께 80 mm,길이 2000 mm인 사각 채널 내부의 수소-공기 예혼합기에서 발생하는 DDT 현상을 수치적으로 고찰하였다. 개발된코드는 채널 내부의 수소-공기 예혼합기의 점화에서 발생하는 폭연과 폭굉으로의 천이과정을 정성적으로 잘 모사하는 것을 확인하였다. 또한 압력분포와 반응진행변수는 DDT의 발생시점과 위치를 잘 파악하는 데 유용한 변수가 될수 있음을 확인하였다. DDT 특성과 관련해서는 채널 내부의 장애물 높이가 높은 경우가 DDT 발생시점이 빠르게나타났으며 DDT가 발생한 위치에서는 충격파와 화염면 위치가 정확하게 일치하는 것을 잘 알 수 있었다. 추가적으로 장애물 높이가 높은 경우가 DDT 발생시점은 빠르지만 DDT 발생 이후의 압력 최고값도 높게 나타나지는 않는것으로 확인되었으며 이것은 충격파와 반사파의 상호작용 등 복잡한 현상에 기인하는 것으로 파악되었다.

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