Numerical Simulation of MHD Fluid Flow inside Constricted Channels using Lattice Boltzmann Method

In this study, the electrically conducting fluid flow inside a channel with local symmetric constrictions, in the presence of a uniform transverse magnetic field is investigated using Lattice Boltzmann Method (LBM). To simulate Magnetohydrodynamics (MHD) flow, the extended model of D2Q9 for MHD has been used. In this model, the magnetic induction equation is solved in a similar manner to hydrodynamic flow field which is easy for programming. This extended model has a capability of simultaneously solving both magnetic and hydrodynamic fields; so that, it is possible to simulate MHD flow for various magnetic Reynolds number (Rem). Moreover, the effects of Rem on the flow characteristics are investigated. It is observed that, an increase in Rem, while keeping the Hartman number (Ha) constant, can control the separation zone; furthermore, comparing to increasing Ha, it doesn't result in a significant pressure drop along the channel

Shearing characteristics of sugar cane (Saccharum offi cinarum L.) stalks as a function of the rate of the applied force.

Abstract This research was carried out to determine the effect of loading rate and internode position on shearing characteristics of sugar cane stalk. The experiments were conducted at three loading rates of 5, 10, and 15 mm min -1 and at ten internode positions down from the flower. Based on the result obtained, loading rate had significant effect on the shear strength and specific shearing energy of the stalk. With increasing loading rate, the shear strength and specific shearing energy increased. Therefore, lower rates of blades are recommended for reducing energy requirement during harvesting and processing sugar cane stalks. In addition, the internode position had a significant effect on the specific shearing energy, while it did not have significant effect on the shear strength. The specific shearing energy increased towards the lower internodes. The average shear strength was obtained as 3.64 MPa varying from 3.03 to 4.43 MPa. The average specific shearing energy was calculated as 51.41 mJ mm -2 ranging from 37.42 to 64.25 mJ mm -2 . The results of this study are useful for designing and optimizing equipment associated with harvesting, threshing, and processin

The comparative effect of group dynamic assessment (GDA) and computerized dynamic assessment (C-DA) on Iranian upper-intermediate EFL learners’ speaking complexity, accuracy, and fluency (CAF)

This study attempted to check the impact of two dynamic assessment (DA) models on speaking CAF. DA, as opposed to static assessment, is conceived as an interactive approach to assessment that integrates teaching and testing into a unified instructional engagement. To achieve the goals of this research, a convenience sample of 90 upper-intermediate male EFL learners that were randomly assigned into GDA, a C-DA, and a non-DA control group participated in the study. Before carrying out the treatment, a speaking pretest was administered to all three groups and their CAF scores were collected. Following that, the treatment using the aforementioned DA and non-DA conventional models was completed in 16 sessions. To check the impact of the treatment, a speaking post-test was given to the groups at the end of the study. Data analysis using ANOVA showed that C-DA and G-DA could significantly increase speaking CAF than the conventional non-DA instruction with C-DA being significantly better than G-DA. The results of this research propose that implementing DA, especially C-DA by the teachers, can enhance the speaking CAF of the L2 learners

Data supporting midpoint-weighting life cycle assessment and energy forms of cumulative exergy demand for horticultural crops

202109 bchyVersion of RecordPublishe

Exergoenvironmental damages assessment of horticultural crops using ReCiPe2016 and cumulative exergy demand frameworks

202106 bchyNot applicableRGC25202719Published24 month

Develop Boltzmann equation to simulate non-Newtonian magneto-hydrodynamic nanofluid flow using power law magnetic Reynolds number

The single relaxation D2Q9 lattice Boltzmann method (LBM) is run in the current research beside the generalized power law model for simulation of non‐Newtonian magneto‐hydrodynamics (MHD) laminar flow field inside a channel with local symmetric constriction. Analytical results of non‐Newtonian fluid flow in a channel without magnetic field, as well as Newtonian fluid flow at various Hartmann No., are used to validate the numerical model. Then, fluid flow simulation is performed for non‐Newtonian fluid with different power law index at various Hartmann No. (Ha ) whereas Reynolds No. are set to be constant in all cases. The present non‐Newtonian fluid can be achieved by adding various nanoparticles such as MWCNT to the base fluid. To explore the effect of magnetic Reynolds No. (Re m ), the fluid flows with different magnetic resistivity are also simulated. Results show that the separation can be controlled by a magnetic field with the penalty of larger friction coefficient and pressure loss along the channel length. In fact, for a specified Re m , the higher the Ha , the larger the pressure loss. It is also observed that the pressure loss is larger for fluids flow with higher power law index and lower Re_m