Three-Dimensional Computational Fluid Flow Analysis of Bio-inspired Corrugated wing at Low Reynolds Number.

A computational study was performed to analyze the airflow over bio-inspired corrugated wings. The bio-inspired corrugated wing profiles were derived from the mid-span section of the forewing of Aeshna Cyanea dragonfly species. Additionally, a hybrid non-corrugated profile was also created possessing geometric similarities with the corrugated airfoils to compare and visualize the effects of corrugation on the fluid flow. The computational analysis was conducted for 4,8-, and 12-degrees angles of attack. Streamlines obtained from the computational analysis results (carried out on ANSYS CFX) showed the formation of secondary flows or vortices that are trapped in the valleys of the corrugated wings which was not observed in the hybrid airfoil. This study also compares the effects of corrugation geometry on fluid flow behavior. It was also seen that the intensity and quantity of the secondary flows increased with the increase in the angle of attack.

Permeability Measurements of 3D Microstructures Generated by Phase Field Simulation of the Solidification of an Al-Si Alloy during Chill Casting

The permeability of the semi-solid state is important for the compensation of volume shrinkage during solidification, since insufficient melt feeding can cause casting defects such as hot cracks or pores. Direct measurement of permeability during the dynamical evolution of solidification structures is almost impossible, and numerical simulations are the best way to obtain quantitative values. Equiaxed solidification of the Al-Si-Mg alloy A356 was simulated on the microscopic scale using the phase field method. Simulated 3D solidification structures for different stages along the solidification path were digitally processed and scaled up to generate 3D models by additive manufacturing via fused filament fabrication (FFF). The Darcy permeability of these models was determined by measuring the flow rate and the pressure drop using glycerol as a model fluid. The main focus of this work is a comparison of the measured permeability to results from computational fluid flow simulations in the phase field framework. In particular, the effect of the geometrical constraint due to isolated domain walls in a unit cell with a periodic microstructure is discussed. A novel method to minimize this effect is presented. For permeability values varying by more than two orders of magnitude, the largest deviation between measured and simulated permeabilities is less than a factor of two.

Computational Fluid Flow Study on the Pressure Fluctuation Caused by the Vortex Flow Arising from Underwater Exercises of Arthritis Patients

Underwater exercise programs are among the nursing programs for which positive effects have been reported with regard to the promotion of good health in diverse subjects, such as patients suffering arthritis, as well as elderly people and middle-aged women. Through many previously conducted studies, subjects participating in underwater exercises have been reported to continuously experience reduced pain, and improvement in muscle strength, flexibility, sense of balance, and muscular endurance. However, few studies have delved into the fundamental phenomena of positive effects of underwater exercises on the human body. In this study, a model of the upper limbs of the human body was used in a simulation of underwater exercises to analyse the resulting pressure fluctuation on the skin of the hands and arms of the model through the methods of computational fluid dynamics. During the simulation of underwater exercises, pressure fluctuation of diverse frequencies, arising from the vortex flow around the articulations of the fingers and hands of the model, were identified and were seen to create varied cutaneous stimulations and massage effects. Such cutaneous stimulations seem to continuously excite capillary vessels situated between hands and finger joints, creating positive effects in blood circulation around pain sites of patients suffering from arthritis.

Magnetic Damping of Liquid Steel Flows in Horizontal Single Belt Casting (HSBC)

A preliminary computational fluid flow model has been developed to simulate the magnetic braking of liquid steel on a water-cooled, rapidly moving, horizontal belt. The liquid steel issuing from the proposed vertical slot-nozzle should ideally move isokinetically with the belt during freezing. In this study, ANSYS Fluent 14.5 software was used to model the 3-D turbulent flow of liquid steel. A 288 core High Performance Computer cluster located at the McGill Metals Processing Centre was used for high-speed computation. The standard k–ε model was used to simulate the turbulence. Similarly, the magnetic induction method was used to calculate the induced heterogeneous magnetic field, from which the current density and electromagnetic forces produced were computed. The behavior of the proposed magnetic flow control was first validated against previous experimental work and was then applied to predict the performance of the proposed slot nozzle. The predicted results show that by applying a DC Magnetic brake to the proposed metal delivery system, near isokinetic conditions can be rapidly established.

Resin Transfer Molding Process: A Numerical Analysis

This work aims to investigate the infiltration of a CaCO3filled resin using experiments and the PAM-RTM software. A preform of glass fiber mat, with dimensions 320 x 150 x 3.6 mm, has been used for experiments conducted at room temperature, with injection pressure of 0.25bar. The resin contained 10 and 40% CaCO3content with particle size 38μm. The numerical results were evaluated by direct comparison with experimental data. The flat flow-front profile of the rectilinear flow was reached approximately halfway the length of the mold. It was observed, that the speed of the filling decreases with increasing CaCO3content and,the higher the amount of CaCO3in the resin, the lower the permeability of the reinforcement that is found. The reduction in permeability is due to the presence of calcium carbonate particles between the fibers, hindering the resin flow in the fibrous media. The computational fluid flow analysis with the PAM-RTM proved to be an accurate tool study for the processing of composite materials.