Abstract

Spray drying is one of many industrial applications that use annular swirling jets. For this particular application, the flow characteristics in the near-field of the jet are fundamental to obtaining high-quality dried products. In this article, an annular swirling jet configuration is numerically studied using three low-cost eddy-resolving turbulence methods: detached-eddy simulation (DES), delayed-DES (DDES) and scale-adaptive simulation (SAS). To focus in industrial applicability, very coarse grids are used. The individual performance of these models is assessed through a comparison with laser-Doppler anemometry (LDA) measurements and large-eddy simulation (LES) data from available studies. Results show that all the three turbulence models are suitable for performing industrial cost-effective simulations, capable of reproducing LES results of mean velocities and first-order turbulence statistics at a fraction of the computational cost. Differences in the results of the evaluated models were minor; however, the simulation with DDES still provided a better reproduction of experimental results, especially in the very-near field of the jet, as it enforced RANS behavior near the inlet walls and a better transition from modeled to resolved scales.

Highlights

  • The aim of this work is to evaluate the capability of detached-eddy simulation (DES), DDES and scale-adaptive simulation (SAS) turbulence models to obtain large-eddy simulation (LES)-like results of the near-field of annular swirling jet for application in industrial simulations of spray drying

  • This paper presents DES, DDES and SAS computations in the near-field of a swirling annular jet

  • The results of the comparison show the cost-effectiveness of the evaluated modeling approach and its applicability to the simulation of spray drying processing and other industrial applications featuring annular-swirling inlets

Read more

Summary

Introduction

Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. The aim of this work is to evaluate the capability of DES, DDES and SAS turbulence models to obtain LES-like results of the near-field of annular swirling jet for application in industrial simulations of spray drying. This works provides a background for a project under development using a similar air disperser configuration to improve the geometrical design of spray drying chambers through parametric CFD analysis.

Governing Equations
Turbulence Modeling
The k-ω SST Model
Detached-Eddy Simulation
The SST-DES Model
SST-Delayed DES Model
SST-SAS Model
Numerical Schemes and Methods
Flow Configuration
Computational Domain
Boundary Conditions
Study Cases and Methodology
Results and Discussion
Description of the Flow Field
Grid Size and Turbulence-Resolving Capabilities
Mean Velocity Profiles
Fluctuations
Error Criteria
Global MAE
MAE per Jet Zones
Conclusions
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call