Voidage correction algorithm for unresolved Euler–Lagrange simulations

Askarishahi, Maryam; Salehi, Mohammadsadegh; Radl, Stefan

doi:10.1007/s40571-018-0193-8

Cited by 19 publications

(3 citation statements)

References 33 publications

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“…Both grids were uniform in the area of interaction between the hot jet and water droplets. The uniform grid remedied numerical problems arising in water-gas interaction region described in the paper [44].…”

Section: Asmentioning

confidence: 99%

The Eulerian–Lagrangian Approach for the Numerical Investigation of an Acoustic Field Generated by a High-Speed Gas-Droplet Flow

Melnikova

Epikhin

Kraposhin

2021

Fluids

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This paper presents the Eulerian–Lagrangian approach for numerical modeling of high-speed gas-droplet flows and aeroacoustics. The proposed hybrid approach is implemented using the OpenFOAM library and two different methods. The first method is based on a hybrid convective terms approximation method employing a Kurganov–Tadmor and PIMPLE scheme. The second method employs the regularized or quasi-gas dynamic equations. The Lagrangian part of the flow description uses the OpenFOAM cloud model. Within this model, the injected droplets are simulated as packages (parcels) of particles with constant mass and diameter within each parcel. According to this model, parcels moving in the gas flow could undergo deceleration, heating, evaporation, and breakup due to hydrodynamic instabilities. The far-field acoustic noise is predicted using Ffowcs Williams and Hawking’s analogy. The Lagrangian model is verified using the cases with droplet evaporation and motion. Numerical investigation of water microjet injection into the hot ideally expanded jet allowed studying acoustic properties and flow structures, which emerged due to the interaction of gas and liquid. Simulation results showed that water injection with a mass flow rate equal to 13% of the gas jet mass flow rate reduced the noise by approximately 2 dB. This result was in good coincidence with the experimental observations, where maximum noise reduction was about 1.6 dB.

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Section: Asmentioning

confidence: 99%

The Eulerian–Lagrangian Approach for the Numerical Investigation of an Acoustic Field Generated by a High-Speed Gas-Droplet Flow

Melnikova

Epikhin

Kraposhin

2021

Fluids

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“…Otherwise the drag force of the particulate phase is not calculated correctly. Askarishahi et al [32] indicate that when flow details around individual particles are not resolved, the mesh cell size varies between 2 and 15 times the particle diameter.…”

Section: Setup Of the Simulationsmentioning

confidence: 99%

Euler–Lagrangian simulation of the fuel spray of a planar prefilming airblast atomizer

et al. 2021

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The pollutant emissions of aircraft engines are strongly affected by the fuel injection into the combustion chamber. Hence, the precise description of the fuel spray is required in order to predict these emissions more reliably. The characteristics of a spray is determined during the atomization process, especially during primary breakup in the vicinity of the atomizer nozzle. Currently, Euler-Lagrangian approaches are used to predict the droplet trajectories in combustor simulations along with reaction and pollutant formation models. To be able to reliably predict pollutant emissions in the future, well-defined starting conditions of the liquid fuel droplets close to the atomizer nozzle are necessary. In the present work, Euler-Lagrangian simulations of a generic airblast atomizer are presented. The starting conditions of the droplets are varied in the simulations by means of a primary breakup model, which takes into account the local gas velocity when predicting the droplet diameter. The objective of this work is to determine the optimal parameters of the probability density functions for the starting position and the starting velocity of the droplets. Spray properties observed in the simulations are used to qualitatively evaluate the major effects of the distribution parameters on the spray and the suitability of the primary breakup model being applied. Hence, the spatial distribution of an experimental spray can be reproduced using a statistical model for the droplet starting conditions.

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“…They found that the global averaging drag forces are clearly different from the homogeneous drag law and the deviations are related to the angles between the flow directions and ∇ϕ s . Askarishahi et al considered the influence of the volume fraction jumps on the interphase drag force in coarse-grid simulation by a voidage correction model. Su and Zhao as well as Li et al considered the influence of the unresolved structure on drag force by different assumptions of the sub-scale solid phase distributions.…”

Section: Introductionmentioning

confidence: 99%

Verification of a Microscale Drag Model Considering the Effect of Gas–Structure Interface Via Fine-Grid Two-Fluid Simulations

Chen

et al. 2023

Ind. Eng. Chem. Res.

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Sharp interfaces between the dilute phase and dense phases are widely reported in both experimental and computational studies of gas−solid fluidized beds. Therefore, the microscale drag model that could account for the influence of the interface is important to the accurate prediction of gas− solid dynamics. This study evaluates the performance of one of such models using fine-grid two-fluid simulations at different grid resolutions. It is found that the simulation results obtained using the interface drag model are closer to the experimental results than those obtained using the homogeneous drag law. The interface drag model can reduce the high demand for grid resolution in fine-grid two-fluid model (TFM) simulation with small particles. It is also found that the difficulty in accurately simulating different fluidized beds is different for homogeneous drag models, i.e., turbulent bed > circulating bed > bubbling bed. However, using the interface drag model, one can obtain gridindependent results for different fluidized beds at a coarser mesh resolution. The interface drag model is also helpful in attenuating the blurriness of the interface between the dilute and dense phases as the grid size increases.

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Voidage correction algorithm for unresolved Euler–Lagrange simulations

Cited by 19 publications

References 33 publications

The Eulerian–Lagrangian Approach for the Numerical Investigation of an Acoustic Field Generated by a High-Speed Gas-Droplet Flow

The Eulerian–Lagrangian Approach for the Numerical Investigation of an Acoustic Field Generated by a High-Speed Gas-Droplet Flow

Euler–Lagrangian simulation of the fuel spray of a planar prefilming airblast atomizer

Verification of a Microscale Drag Model Considering the Effect of Gas–Structure Interface Via Fine-Grid Two-Fluid Simulations

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