Stress Overshoot Analysis in Flow Start-Up Tests: Aging Time Fitting of the Different Gel-Based Drilling Fluids.

Drilling fluids are essential for maintaining cutting suspension during drilling, exhibiting gel-like behavior at rest and liquid-like behavior under shearing. These fluids display shear-thinning behavior, yield stress, and thixotropy. This study investigates the impact of aging time on stress overshoot and the deformation required to disrupt the gelled structure of water-based and synthetic-based drilling fluids.

Visualizing flow dynamics and restart of Carbopol gel solutions in tube and parallel-plates geometries with wall slip.

The present study examines the impact of slip in Carbopol solutions during the restart flow in pipelines utilizing visualization techniques. Rheological tests were conducted using smooth and hatched parallel plate geometries to obtain the rheological characteristics of the solutions. The behavior of the solutions in the creep tests is compared with those in the experimental unit.

Numerical investigation of viscoplastic fluids on natural convection in open cavities with solid obstacles.

This study investigates the natural convection process within open cavities filled with viscoplastic fluid following the Bingham model with solid square conductive blocks uniformly distributed throughout the cavity. The problem is modeled as a two-dimensional laminar in a steady state with the heated surface parallel to the cavity opening and the other adiabatic surfaces. Three geometries are analyzed: the downward-facing cavity, side-facing cavity, and upward-facing cavity.

Multi-block analysis for the correlation of physico-chemical and rheological data of 42 fruit pulps.

The common dimension (ComDim) chemometric method for multi-block analysis and hierarchical cluster analysis (HCA) were used to evaluate the data obtained from the physico-chemical and rheological characterization of 42 commercial fruit pulps. The physico-chemical characteristics and the rheological behavior of the pulps were found to be considerably different. The Herschel-Bulkley equation was fit to the steady-state flow curves of the fruit pulps, and it was found to appropriately describe the materials, which showed a wide range of yield stresses.