• Title/Summary/Keyword: Direct quadrature method of moments

Search Result 5, Processing Time 0.019 seconds

Numerical Modeling of Soot Formation in $C_2H_4$/Air Turbulent Non-premixed Flames ($C_2H_4$/Air 비예혼합 난류화염의 매연생성 모델링)

  • Kim, Tae-Hoon;Woo, Min-O;Kim, Yong-Mo
    • Journal of the Korean Society of Combustion
    • /
    • v.15 no.4
    • /
    • pp.22-28
    • /
    • 2010
  • The Direct Quadrature Method of Moments (DQMOM) has been presented for the solution of population balance equation in the wide range of the multi-phase flows. This method has the inherently interesting features which can be easily applied to the multi-inner variable equation. In addition, DQMOM is capable of easily coupling the gas phase with the discrete phases while it requires the relatively low computational cost. Soot inception, subsequent aggregation, surface growth and oxidation are described through a population balance model solved with the DQMOM for soot formation. This approach is also able to represent the evolution of the soot particle size distribution. The turbulence-chemistry interaction is represented by the laminar flamelet model together with the presumed PDF approach and the spherical harmonic P-1 approximation is adopted to account for the radiative heat transfer.

Numerical Investigations of Turbulent Piloted Non-Premixed Flames (난류 Pilot 비예혼합 화염장의 상세구조 해석)

  • Lee, Jeonwon;Jeon, Sangtae;Kim, Yongmo
    • 한국연소학회:학술대회논문집
    • /
    • 2014.11a
    • /
    • pp.185-186
    • /
    • 2014
  • The multi-environment probability density function model has been applied to simulate the turbulent stratified premixed flames. The direct quadrature method of moments (DQMOM) has been adopted to solve the transport PDF equation due to its computational efficiency and robustness. The IEM mixing model is employed to represent the mixing process and the chemical mechanism is based on Gri 3.0 mechanism. Numerical results obtained in this study are precisely compared with experimental data in terms of unconditional and conditional means for scalar fields and velocity fields.

  • PDF

Nonlinear Bearing Only Target Tracking Filter (방위각 정보만을 이용한 비선형 표적추적필터)

  • Yoon, Jangho
    • Journal of Aerospace System Engineering
    • /
    • v.10 no.1
    • /
    • pp.8-14
    • /
    • 2016
  • The optimal estimation of a bearing only target tracking problem be achieved through the solution of the Fokker-Planck equation and the Bayesian update. Recently, a nonlinear filtering algorithm using a direct quadrature method of moments in which the associated Fokker-Planck equation can be propagated efficiently and accurately was proposed. Although this approach has demonstrated its promising in the field of nonlinear filtering in several examples, the "degeneracy" phenomenon, similar to that which exists in a typical particle filter, occasionally appears because only the weights are updated in the modified Bayesian rule in this algorithm. Therefore, in this paper to enhance the performance, a more stable measurement update process based upon the update equation in the Extended Kalman filters and a more accurate initialization and re-sampling strategy for weight and abscissas are proposed. Simulations are used to show the effectiveness of the proposed filter and the obtained results are promising.

Numerical Investigations of Turbulent Stratified Premixed Flames (난류 성층 예혼합 화염장의 상세구조 해석)

  • Jeon, Sangtae;Kim, Namsu;Kim, Yongmo
    • 한국연소학회:학술대회논문집
    • /
    • 2014.11a
    • /
    • pp.183-184
    • /
    • 2014
  • The multi-environment probability density function model has been applied to simulate the turbulent stratified premixed flames. The direct quadrature method of moments (DQMOM) has been adopted to solve the transport PDF equation due to its computational efficiency and robustness. Computations are made for the non-swirling turbulent stratified premixed flames including SWB1, SWB5 and SWB9. The numerical results obtained in this study are precisely compared with experimental data in terms of axial velocity, unconditional means and conditional means for scalar field including temperature and species mass fraction.

  • PDF

Numerical Investigations of Turbulent CH4/H2 flames under MILD combustion condition (MILD 연소환경에서의 난류 CH4/H2 난류 화염장 해석)

  • Jeon, Sangtae;Kim, Yongmo
    • 한국연소학회:학술대회논문집
    • /
    • 2015.12a
    • /
    • pp.267-268
    • /
    • 2015
  • The multi-environment probability density function model has been applied to simulate the turbulent $CH_4/H_2$ flames under MILD conditions. The direct quadrature method of moments (DQMOM) has been adopted to solve the transport PDF equation due to its computational efficiency and robustness. The IEM model represents the micromixing process. The numerical results obtained in this study are precisely compared with experimental data in terms of unconditional means and conditional means for scalar field including temperature and species mass fraction.

  • PDF