Newsletter  2023.10  Index

Theme : "AJK FED 2023" Preface Hyun Jin PARK, Shoichi MATSUDA, Chungpyo HONG Evaluation of railway vehicles' resistance against strong crosswinds and its application for safe railway operation Yayoi MISU (East Japan Railway Company) Order within Turbulence Susumu GOTO (Osaka University), Yutaro MOTOORI (Osaka University) LES/Lagrangian-particle-simulation of a Reactive Turbulent Planar Jet Jiabao Xing (Nagoya University)，Tomoaki WATANABE (Nagoya University)，and Koji NAGATA (Kyoto University) Unsteady Characteristics of Tip Leakage Vortex Cavitation in the Occurrence of Cavitation Instability in Liquid Rocket Inducer Koki TAMURA (Tohoku University)，Yuto NAKURA (Tohoku University), Satoshi KAWASAKI (Japan Aerospace Exploration Agency), Yuka IGA (Tohoku University) Water Condensation in PEMFCs at Nano-scale: Insights through Lattice DFT simulations Clint John Cortes OTIC (The University of Tokyo), Masazumi ARAO (FC-Cubic), Masashi MATSUMOTO (FC-Cubic), Hideto IMAI (FC-Cubic), Ikuya KINEFUCHI (The University of Tokyo) Reconstruction of Fluid Stress Field from Flow Birefringence using Physics-Informed Convolutional Encoder-Decoder (PICED) Daichi IGARASHI (Tokyo University of Agriculture and Technology), Shun MIYATAKE (Tokyo University of Agriculture and Technology), Jingzu YEE (Tokyo University of Agriculture and Technology), Yoshiyuki TAGAWA (Tokyo University of Agriculture and Technology) Determination of Permeability in the Volume Penalisation Method with a Smooth Mask Function Taichi TSUJIMOTO (Osaka University), Yuta NAKAO (Osaka University), Takuya TSUJI (Osaka University), Toshitsugu TANAKA (Osaka University), Kimiaki WASHINO (Osaka University)

 

LES/Lagrangian-particle-simulation of a Reactive Turbulent Planar Jet

Jiabao Xing Nagoya University,　 Tomoaki WATANABE Nagoya University,　 Koji NAGATA Kyoto University

Abstract

Understanding mixing and chemical reactions in compressible turbulence has many potential applications, such as designing propulsion systems. This study applies Lagrangian particle simulation (LPS) combined with large eddy simulation (LES) to investigate the mixing and reaction in a temporally evolving turbulent planar jet with a subsonic or supersonic jet velocity. The present study assumes an isothermal and second-order chemical reaction A + B→P, where A and B are supplied from the jet and ambient fluids, respectively.

LES solves Navier–Stokes equations of compressible fluid with a finite difference method, while LPS solves scalar transport equations with notional particles. Each particle is described by its location and scalar values, such as mass fractions. The particle movement modelled by the resolved velocity of LES represents the advective scalar transport. The molecular diffusion is modelled by a mixing volume model extended to compressible turbulence, while the chemical reaction term is directly evaluated with the scalars assigned to each particle.

The results of LES/LPS for the jet Mach number of  are compared with the direct numerical simulation (DNS) of the same flow. Figure 1 shows two-dimensional profiles of the mass fraction of product P on an  plane in the fully developed turbulent jet. The LES/LPS well predicts the spatial distribution of the product. We have also confirmed that the cross-streamwise distributions of mass-fraction statistics are in good agreement between the LES/LPS and DNS, e.g., Fig. 2.

In conclusion, we believe that LES/LPS with the mixing volume model is expected to be a promising method for investigating compressible turbulent reactive flows at a moderate computational cost.

Key words

Large eddy simulation, Lagrangian particle simulation, Mixing model, Reacting flows, Supersonic jet

Figures

Fig. 1  Instantaneous distribution of the mass fraction of product, , on an xy plane for  obtained by (a) DNS and (b) LES/LPS.

Fig. 2  Mean mass fraction of reactants (a) A and (b) B at  and . The jet half width defined with mean mixture fraction, , is used to normalize the transverse position .