Research Article
Computational Analysis of Yield Stress Fluid Behavior over a Heated Surface-mounted Block with
Temperature-dependent Viscosity
Issue:
Volume 12, Issue 2, June 2026
Pages:
24-31
Received:
2 April 2026
Accepted:
17 April 2026
Published:
21 May 2026
DOI:
10.11648/j.ijfmts.20261202.11
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Abstract: A numerical investigation of laminar viscoplastic flow past a heated square cylinder on a plane wall is presented using the Bingham and Casson models with Papanastasiou regularization. A two-step methodology first establishes fully developed channel flow at Re = 100, then uses it as inflow for the main problem at Re = 500. Effects of Bingham number (Bn = 0, 10, 30) on flow structure are examined. Results show progressive growth of unyielded zones (black regions) with increasing Bn, where fluid behaves as a rigid solid body. At Bn = 0, no unyielded zones exist, and symmetric streamlines with recirculation are observed. At Bn = 10, unyielded zones emerge upstream and, in the wake, suppressing vortex formation. At Bn = 30, these zones form an elongated rigid plug that eliminates recirculation. The regularized model captures yield surface evolution without numerical instability. Yield stress fundamentally governs flow morphology; unyielded regions grow and coalesce as Bn increases, reducing deformation and suppressing convective mixing with significant implications for heat transfer. Temperature-dependent viscosity is characterized by the Pearson number Pn, while the Casson number Ca represents the yield stress to viscous force ratio. This study aids design of thermal systems for heat exchangers, polymer processing, food sterilization, drilling operations, and biomedical devices.
Abstract: A numerical investigation of laminar viscoplastic flow past a heated square cylinder on a plane wall is presented using the Bingham and Casson models with Papanastasiou regularization. A two-step methodology first establishes fully developed channel flow at Re = 100, then uses it as inflow for the main problem at Re = 500. Effects of Bingham number...
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