Investigation of the Prediction Performance of Turbulence and Combustion Models for the Turbulent Partially-premixed Jet Flame

Yu Jeong, Kim; Chang Bo, Oh

doi:2014.28.4.35

Fire Sci. Eng. > Volume 28(4); 2014 > Article

Fire Science and Engineering 2014;28(4):35-43.
DOI: https://doi.org/10.7731/KIFSE.2014.28.4.035 Published online August 31, 2014.

난류 부분예혼합 제트화염에 대한 난류 및 연소모델의 예측성능 검토

김유정, 오창보

¹부경대학교 안전공학과
²부경대학교 안전공학과

Investigation of the Prediction Performance of Turbulence and Combustion Models for the Turbulent Partially-premixed Jet Flame

Kim Yu Jeong, Oh Chang Bo

¹Pukyong National University, Department of Safety
²Pukyong National University, Department of Safety

요약

3개의 난류모델과 3개의 연소모델로 구성된 9개의 모델조합을 이용하여 난류 부분예혼합 제트화염 구조에 대한 수치적 예측성능을 검토하였다. 이용된 난류모델은 표준 ${kappa}-{varepsilon}$ 모델(SKE), Realizable ${kappa}-{varepsilon}$ 모델(RKE) 및 Reynolds 응력모델(RSM)이며 연소모델들은 Eddy Dissipation Concept 모델(EDC), Steady Laminar Flamelet 모델(SLF)와 Unsteady Laminar Flamelet 모델(ULF)이다. 9개 모델조합의 예측성능을 평가하기 위하여 실험결과가 알려진 Sandia D 화염인 난류 부분예혼합 제트화염을 대상으로 수치계산을 수행하였다. 얻어진 결과로서, 화염길이의 예측은 RSM > SKE > RKE순으로 길게 예측하였으며, RKE 난류모델은 화염길이를 너무 과소 예측하는 것을 확인하였다. RSM + SLF과 RSM + ULF의 조합은 화염길이는 비교적 잘 예측하였지만 하류에서의 화염온도를 과대 예측하였다. 반면에 SKE와 연소모델의 조합에서 SLF 또는 ULF 조합은 화염길이 뿐만 아니라 하류에서의 화염온도도 비교적 잘 예측하였는 것을 확인하였다. 반경방향 화염온도 및 화학종 농도분포를 비교해 본 결과 SKE와 연소모델의 조합이 가장 예측성능이 뛰어났으며 SKE + ULF의 조합이 가장 우수한 예측성능을 갖는 것을 확인하였다.

Abstract

The prediction performance of 9 model sets, which combine 3 turbulent models and 3 combustion models, was investigated numerically for turbulent partially-premixed jet flame. The standard ${kappa}-{varepsilon}$ (SKE), Realizable ${kappa}-{varepsilon}$ (RKE) and Reynolds stress model (RSM) were used as a turbulence model, and the eddy dissipation concept (EDC), steady laminar flamelet (SLF) and unsteady laminar flamelet model (ULF) were also adopted as a combustion model. The prediction performance of those 9 model sets was evaluated quantitatively and qualitatively for Sandia D flame of which flame structure was measured precisely. The flame length was predicted as, from longest to shortest, RSM > SKE > RKE, and the RKE predicted the flame length of the jet flame much shorter than experiment. The flame temperature was over predicted by the combination of RSM + SLF or RSM + ULF while the flame length obtained by RSM + SLF and RSM + ULF was well agreed with the experiment. The combination of SKE + SLF and SKE + ULF predicts well the flame length as well as the temperature distribution. The SKE turbulence model was most superior to the other turbulent models, and SKE + ULF showed the best prediction performance for the structure of turbulent partially-premixed jet flame.

Key Words: Partially-premixed flame, Turbulence model, Combustion model, Jet flame, Sandia D flame, Turbulent flame