Linear Shear Flow Past a Rotating Elliptic Cylinder

2018 ◽  
Vol 140 (12) ◽  
Author(s):  
Sandeep N. Naik ◽  
S. Vengadesan ◽  
K. Arul Prakash
Keyword(s):  
Shear Flow ◽  
Immersed Boundary Method ◽  
Elliptic Cylinder ◽  
Immersed Boundary ◽  
Axis Ratio ◽  
Rotation Rates ◽  
Flow Past ◽  
Shear Parameter ◽  
Linear Shear ◽  
Flow Features

Simulations are carried out for linear shear flow past a rotating elliptic cylinder to investigate the effect of shear flow on hovering vortex. An in-house fluid solver that is based on immersed boundary method (IBM) is used to study the flow features and variation in aerodynamic forces. The simulations are carried out for various nondimensional rotation rates, axis ratio (AR) of the cylinder, and shear parameter. In shear flow past rotating elliptic cylinder, the negative vortices are sustained for longer distances in the downstream of the cylinder, and due to the velocity gradient, the sequence of the vortex street changes. It also has significant effect on the formation and composition of hovering vortex. To capture these features, each vortex is tracked as they form, detach, and move in the wake of the cylinder. Hovering vortex, formed due to coalescing of multiple vortices near the cylinder, is subdued for smaller rotation rates at moderate shear. It is also observed that lift forces increase linearly with shear, while the frequency of shedding shows no dependency on shear parameter.

Flow Past Rotating Low Axis Ratio Elliptic Cylinder

2016 ◽  
Author(s):  
Sandeep N. Naik ◽  
S. Vengadesan ◽  
K. Arul
Keyword(s):  
Elliptic Cylinder ◽  
Axis Ratio ◽  
Flow Past

Influence of Rounded Corners on Flow Interference Due to Square Cylinders Using Immersed Boundary Method

2012 ◽  
Vol 134 (9) ◽  
Author(s):  
M. B. Shyam Kumar ◽  
S. Vengadesan
Keyword(s):  
Immersed Boundary Method ◽  
Bluff Body ◽  
Immersed Boundary ◽  
Drag Coefficients ◽  
Square Cylinders ◽  
Flow Past ◽  
Corner Radius ◽  
Boundary Method ◽  
Lift And Drag ◽  
Flow Interference

The influence of rounded corners on the aerodynamic forces and flow interference has been studied in detail for a uniform flow past two side-by-side arranged square cylinders. The Reynolds number (Re) based on the cylinder diameter (D) and free stream velocity (U∞) is 100. Numerical simulations are carried out for seven different transverse gap ratios (T/D), each with a minimum and maximum corner radius. An inbuilt finite difference code with staggered arrangement of flow variables is used to discretize the governing equations. The concept of immersed boundary method (IBM) is employed to simulate flow around rounded corners using the regular Cartesian grids. The computational code was validated for flow past an isolated circular cylinder, square cylinder, and two equal sized circular cylinders and the results were found to be in very good agreement with available literatures. In the present study, results in terms of the mean and rms values of lift and drag coefficients, Strouhal number, phase diagrams, and contours of streamlines and vorticity are presented. As the corner radius is increased, a reduction in the drag force is observed. There exists a significant effect of gap ratio and corner radius on the phase angle of lift and drag coefficients. Three different flow patterns, namely the single bluff body flow, biased gapside flow, and two independent bluff body flows, were observed from this study.

MHD flow past a circular cylinder using the immersed boundary method

2010 ◽  
Vol 39 (2) ◽  
pp. 345-358 ◽  
Author(s):  
D.G.E. Grigoriadis ◽  
I.E. Sarris ◽  
S.C. Kassinos
Keyword(s):  
Circular Cylinder ◽  
Immersed Boundary Method ◽  
Mhd Flow ◽  
Immersed Boundary ◽  
Flow Past ◽  
Boundary Method

Shear Layer Interactions With Fluid–Fluid Interface in the Wake of an Elliptical Cylinder

2020 ◽  
Vol 142 (8) ◽  
Author(s):  
Prashant Khandelwal ◽  
Rahul Subburaj ◽  
S. Vengadesan
Keyword(s):  
Shear Layer ◽  
Froude Number ◽  
Level Set ◽  
Immersed Boundary Method ◽  
Elliptic Cylinder ◽  
Elliptical Cylinder ◽  
Immersed Boundary ◽  
Angle Of Incidence ◽  
Fluid Interface ◽  
Numerical Solver

Abstract In this study, wake of an elliptic cylinder is analyzed in the presence of a fluid–fluid interface. The interactions between the interface and flow affect each other and hence different wake dynamics and interface topologies are observed. The numerical solver developed for this study has immersed boundary method (IBM) coupled with level-set method (LSM). The proximity of the elliptical cylinder to the interface (H/D), Froude number (Fr), and angle of incidence (AOI) are the parameters considered. Three different Froude number regimes are considered for this study, namely, subcritical (Fr < 1), critical (Fr = 1.0), and supercritical (Fr >1) regime. In this paper, the interface topology, wake dynamics, and force values are compared for the variation of these parameters.

APPLICATION OF IMMERSED BOUNDARY METHOD ON INSTRUMENTED TURBINE BLADE WITH LES

2021 ◽  
pp. 1-11
Author(s):  
Bryn N Ubald ◽  
Rob Watson ◽  
Jiahuan Cui ◽  
Paul G. Tucker ◽  
Shahrokh Shahpar
Keyword(s):  
Immersed Boundary Method ◽  
Pressure Loss ◽  
Turbine Blades ◽  
Leading Edge ◽  
Immersed Boundary ◽  
Eddy Simulation ◽  
Boundary Method ◽  
Flow Features ◽  
Compressor And Turbine Blades ◽  
High Level

Abstract Leading edge instrumentation used in compressor and turbine blades for jet-engine test rigs can cause significant obstruction and lead to a marked increase in downstream pressure loss. Typical instrumentation used in such a scenario could be a Kiel shrouded probe with either a thermocouple or pitot-static tube for temperature/pressure measurement. High fidelity analysis of a coupled blade and probe requires the generation of a high-quality mesh which can take a significant amount of an engineer's time. The application of Immersed Boundary Method (IBM) and Large Eddy Simulation is shown in this paper to enable the use of an extremely simple mesh to observe the primary flow features generated due to the blade and probe interaction effects, as well as quantify downstream pressure loss to within a high level of accuracy. IBM is utilised to approximately model the probe, while fully resolving the blade itself through a series of LES simulations. This method has shown to be able to capture downstream loss profiles as well as integral quantities compared to both experiment and fully wall resolved LES without the need to spend a significant amount of time generating the ideal mesh. Additionally, it is also able to capture the turbulence anisotropy surrounding the probe and blade regions.

Application of Immersed Boundary Method on Instrumented Turbine Blade With LES

2020 ◽  
Author(s):  
Bryn N. Ubald ◽  
Rob Watson ◽  
Jiahuan Cui ◽  
Paul Tucker ◽  
Shahrokh Shahpar
Keyword(s):  
Immersed Boundary Method ◽  
Pressure Loss ◽  
Turbine Blades ◽  
Leading Edge ◽  
Immersed Boundary ◽  
Eddy Simulation ◽  
Boundary Method ◽  
Flow Features ◽  
Compressor And Turbine Blades ◽  
High Level

Abstract Leading edge instrumentation used in compressor and turbine blades for jet-engine test rigs can cause significant obstruction and lead to a marked increase in downstream pressure loss. Typical instrumentation used in such a scenario could be a Kiel-shrouded probe with either a thermocouple or pitot-static tube for temperature/pressure measurement. High fidelity analysis of a coupled blade and probe requires the generation of a high quality mesh which can take a significant amount of an engineers time. The application of Immersed Boundary Method (IBM) and Large Eddy Simulation is shown in this paper to enable the use of an extremely simple mesh to observe the primary flow features generated due to the blade and probe interaction effects, as well as quantify downstream pressure loss to within a high level of accuracy. IBM is utilised to approximately model the probe, while fully resolving the blade itself through a series of LES simulations. This method has shown to be able to capture downstream loss profiles as well as integral quantities compared to both experiment and fully wall-resolved LES without the need to spend a significant amount of time generating the ideal mesh. Additionally, it is also able to capture the turbulence anisotropy surrounding the probe and blade regions.

Benchmark simulations of flow past rigid bodies using an open-source, sharp interface immersed boundary method

2017 ◽  
Vol 1 (1) ◽  
pp. 1 ◽  
Author(s):  
Clarence W. Rowley ◽  
Alexander J. Smits ◽  
Nicoleta Herzog ◽  
Hrvoje Jasak ◽  
Daniel Brunner ◽  
...  
Keyword(s):  
Open Source ◽  
Immersed Boundary Method ◽  
Rigid Bodies ◽  
Sharp Interface ◽  
Immersed Boundary ◽  
Flow Past ◽  
Boundary Method

scholarly journals An Improved Direct-Forcing Immersed Boundary Method for Fluid-Structure Interaction Simulations

2013 ◽  
Author(s):  
Xing Zhang ◽  
Xiaojue Zhu ◽  
Guowei He
Keyword(s):  
Immersed Boundary Method ◽  
Fluid Structure Interaction ◽  
Three Dimensional ◽  
Immersed Boundary ◽  
Fluid Structure ◽  
Structure Interaction ◽  
Dimensional Flow ◽  
Flow Past ◽  
Boundary Method ◽  
Direct Forcing

Simulation of fluid-structure interaction (FSI) of flexible bodies are challenging due to complex geometries and freely moving boundaries. Immersed boundary method has found to be an efficient technique for dealing with FSI problems because of the use of non-body-fitted mesh and simple implementation. In the present work, we developed a FSI solver by coupling a direct forcing immersed boundary method for the fluid with a finite difference method of the structure. Several flow problems are simulated to validate our method. The testing cases include flow over a stationary cylinder and flat plate, two-dimensional flow past an inextensible flexible filament and three-dimensional flow past a flag. The results obtained agree well with those from previously published literatures.

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