Large eddy simulation of a turbulent supercritical hydrothermal flame with a novel direct moment closure model. (15th January 2023)

• Record Type: Journal Article
• Authors: Liu, Runzhi; Luo, Kun; Song, Changcheng; Jin, Tai; Chai, Min; Fan, Jianren
• Is Part Of: Fuel. Volume 332(2023)Part 1
• Publication Date: 2023-01-15
• Subjects: Turbulent combustion -- Direct moment closure -- Direct numerical simulation -- Large eddy simulation -- Supercritical hydrothermal flame; Fuel -- Periodicals; Coal -- Periodicals; Coal; Fuel; Periodicals; 662.6
• DOI: 10.1016/j.fuel.2022.126037
• Languages: English
• ISSNs: 0016-2361

Abstract

Highlights: A novel direct moment closure model has been developed and comprehensively evaluated. A turbulent supercritical hydrothermal flame has been numerically simulated. The coupled LES and the direct moment closure model can reproduce the flame. The novel model performs much better than the laminar chemistry closure model. Abstract: A novel direct moment closure (DMC) model has been developed in the context of large eddy simulation (LES) and applied to simulate a supercritical flame. To evaluate the performance of the model, three-dimensional direct numerical simulation (DNS) of a supercritical hydrothermal non-premixed jet flame is conducted. The characteristics of the ignition and propagation of the supercritical hydrothermal flame are analyzed, and then the a-priori analysis of the DMC model is carried out based on the DNS model data. It is found that the prediction of reaction rate can be remarkably improved by the DMC model compared with the laminar chemistry closure (LCC) model. In the a-posteriori study, LES of the turbulent supercritical hydrothermal flame with the DMC and LCC models have been performed and compared with the DNS data respectively. It turns out that the LES-DMC model can successfully reproduce the complex behaviors of the turbulent supercritical hydrothermal flame, and the predicted mean and rms values of velocities, temperature, and species are more accurate than those of the LES-LCC model.