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.

Cavity for Flow Control and Performance Improvement of Airfoil

The fluid flow analysis over a cambered airfoil having three different cavity locations on the suction surface is reported in this paper. The Elliptical cavity is created at LE, MC, and TE along chordwise locations from the leading to trailing edge. In this regard, the steady simulation is carried out in the Fluent at Reynolds number of 105 based on their chord length. The lift and drag characteristics for clean and cavities airfoil are investigated at different angles of attack. For the clean airfoil, the stall point is observed at 18°. The presence of a cavity improves the stall and aerodynamic characteristics of airfoil. It has been seen that the lift and drag coefficients for pre-stalled or lower angles are nearly similar to clean and cavity at MC or TE positions. For the post-stall point, the improvement in the aerodynamic performance is seen for the cavity at MC or TE. The cavity placed at LE produces lower lift and higher drag characteristics against other configuration models. The overall cavity effect for the flow around the airfoil is that it creates vortices, thereby re-energizes the slower moving boundary layer and delays the flow separation in the downstream direction. The outcomes of this analysis are suggested that the cavity at a position before the mid chord from the leading edge does not improve the performance of the airfoil. Though vortex is formed in the confined spaces but it is unable to reattach the flow towards the downstream direction of an airfoil.

Magnetorheological finishing of small gear teeth profiles using novel workpiece fixture

Miniature gears are essential components of transmitting power in tiny motors used in the aviation, automobile, and healthcare sectors etc. Because of the intricacy of its shape, nanofinishing of tiny gear is a tough job. The rotational magnetorheological abrasive flow finishing (R-MRAFF) technique is a new hybrid methodology for the generation of nano-meter range surface finishing. These surfaces reduce friction between integrating parts, extending their life span. In the current study, a model for simulating the impacts of the R-MRAFF technique was developed using finite element (FE) analysis software, namely COMSOL® Multiphysics. The impacts of various process factors on the fluid flow characteristics while finishing the gear component are investigated using magnetostatic fluid flow analysis of magnetorheological polishing fluid (MRPF) in 3D computational domain of new workpiece fixture. To evaluate the forces operating in R-MRAFF technique, a viscosity model for MRP fluid flow around a complicated component (small steel gear) in an outside magnetic field is recognized and simulated. The magnetic field has a major impact on processing effectiveness by controlling the MRPF viscosity. During the polishing of the gear component, the surface finish attained at various places on working surfaces is uniform, which is confirmed by surface characterization of teeth profiles of small gear.

Fluid Flow Analysis of Agitation Pipe in the Electroplated Diamond Wire Saw

Agitation pipe is the important part of the electroplated diamond wire saw in the suspension sanding process. The structure type and the sandblasting configuration in agitation pipe play a role on the flow uniformity. Fluid flow in the different structure forms of agitating pipe was studied and the influence of sandblasting angle and the diameter was also contrasted. Results found that the central water type of agitation pipe has the better performance, generating the flow field distribution in the middle part with high velocity and small velocity on both sides. The order of sandblasting in performance was 30°, 45° and 60°. The better flow uniformity occurred in the configuration of sandblasting with the diameter 7.5 mm, 7 mm and 7.5 mm.

Heat Transfer and Fluid Flow Analysis for Turbulent Flow in Circular Pipe with Vortex Generator

The performance of heat transfer enhancement (HTE) using modified inserts (MIs) as a vortex generator in pipe flow and fluid flow analysis using computational fluid dynamics (CFD) are evaluated in this article. The MIs are fastened to the central rod, and the circular sections of the MIs touched the circular wall of the test pipe. Heat transfer and fluid flow analyses are carried out for the various pitch to diameter ratios (P/D) and angles of the MIs. P/D ratios of 3, 4 and 6 and MIs angles of 15°, 30°, 45°, 60° and 90° are considered for experimental analysis. CFD analysis is carried out for P/D ratios of 3, 4 and 6 and MIs angles of 30°, 45° and 90°. Nusselt number (Nu/Nus) and friction factor (f/fs) ratios are evaluated using the same Reynolds number between 8000 and 17,000 in the experimental study. The MIs encourage the wall and core fluid to be combined thus helps in HTE. It is found that, as the P/D ratio increases, the Nu/Nus and f/fs decrease. If the distance between the MIs increases, the mixing of fluid weakens. With decreasing the P/D ratio, Nu/Nus increases. Increased fluid mixing leads to a higher coefficient of heat transfer and higher values of pressure drop. A P/D ratio of 4 and MIs angle of 45° results in greater heat interaction than others. Finally, recommendations for the best P/D ratio and angles of MIs are made for improved HTE on fluid flow through a circular pipe. Article Highlights Modified inserts (MIs) are used inside the test pipe to check the heat transfer enhancement at various angles. Also, compared the performance with and without MIs. Fluid flow analysis is checked by CFD (Fluent) in Ansys software. Fluid flow patterns for various MIs angles and P/D ratios are compared.