Numerical study on the influence of outlet diameters on the discharge characteristics of dual-outlet silos

Xuanyi Liu; Fei Wang; Sijiu Qi

doi:10.2478/pjct-2026-0002

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Numerical study on the influence of outlet diameters on the discharge characteristics of dual-outlet silos

Green Sciences

Volume 28 (2026): Issue 1 (March 2026)

By: Xuanyi Liu, Fei Wang and Sijiu Qi

Open Access

|Apr 2026

Abstract

The efficient and safe discharge of powders from multi-outlet silos is critical in many industrial processes. This study applied a two-fluid model to investigate powder-gas dynamics in a dual-outlet silo with outlet diameters of 0.26–0.78 m. Results show that larger outlets accelerate subsidence of the free surface, deepen local depressions, and significantly raise particle velocities, leading to expansion of rapid-flow regions near the outlets. The powder volume fraction exhibits a W-shaped profile in the upper silo and a V-shaped distribution close to the outlets, reflecting the combined effects of gravity and silo geometry. Negative pressure zones consistently emerge above the outlets during early discharge; increasing outlet size not only amplifies these pressure peaks but also promotes faster recovery. Moreover, slight competitive effects between the two outlets were identified, indicating interaction in discharge pathways. These findings demonstrate that outlet diameter is a critical parameter governing both flow dynamics and discharge performance in dual-outlet silos.

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Articles in this issue

DOI: https://doi.org/10.2478/pjct-2026-0002 | Journal eISSN: 3072-0389

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Language: English

Page range: 17 - 32

Submitted on: Sep 30, 2025

Accepted on: Feb 8, 2026

Published on: Apr 27, 2026

Published by: West Pomeranian University of Technology, Szczecin

In partnership with: Paradigm Publishing Services

Publication frequency: Volume open

Keywords:

Numerical simulation,

Two-fluid model,

Dual-outlet silo,

Outlet diameter,

Discharge characteristics.

Related subjects:

Industrial chemistry,

Biotechnology,

Chemical engineering,

Process engineering

© 2026 Xuanyi Liu, Fei Wang, Sijiu Qi, published by West Pomeranian University of Technology, Szczecin
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Volume 28 (2026): Issue 1 (March 2026)