Browsing by Author "Majumdar, S."

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    LES of flow over a circular cylinder at high Reynolds number
    (Indian Institute of Technology, IIT, Kanpur, 2011) Rajani, B.N.; Kandasamy, A.; Majumdar, S.
    Turbulent flow past a circular cylinder at Re = 1.4 × 105 has been analysed using Large Eddy Simulation (LES) approach solving filtered unsteady 3D NS equations coupled to Smagorinsky and dynamic subgrid scale (SGS) models. These simulations have been carried out using a parallel multiblock structured code which employs an implicit second-order accurate pressure-based finite volume method for solving Navier-Stokes equations for unsteady turbulent incompressible flow situations. The predictions are validated against detailed measurement data for mean as well as turbulence quantities. © IUTAM Symposium on Bluff Body Flows, Blubof 2011.
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    LES of flow past circular cylinder at Re = 3900
    (2016) Rajani, B.N.; Kandasamy, A.; Majumdar, S.
    Transitional flow past a circular cylinder in the lower subcritical regime (Re = 3900) has been analysed using Large Eddy Simulation (LES) coupled to Smagorinsky and dynamic sub grid scale models. These simulations have been carried out using a parallel multiblock structured finite volume code which is based on SIMPLE algorithm. The predictions are validated against detailed measurement data for mean as well as turbulence quantities. The present LES prediction in general agree reasonably well with the measurement data in the near wake region but deviates from the measurement data in the far wake region which may be due to the coarse resolution of the grid in this region. The influence of the SGS model on mean flow quantities as well as on the flow structures are also discussed.
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    LES of flow past circular cylinder at Re = 3900
    (Isfahan University of Technology secretary@jafmonline.net, 2016) Rajani, B.N.; Kandasamy, A.; Majumdar, S.
    Transitional flow past a circular cylinder in the lower subcritical regime (Re = 3900) has been analysed using Large Eddy Simulation (LES) coupled to Smagorinsky and dynamic sub grid scale models. These simulations have been carried out using a parallel multiblock structured finite volume code which is based on SIMPLE algorithm. The predictions are validated against detailed measurement data for mean as well as turbulence quantities. The present LES prediction in general agree reasonably well with the measurement data in the near wake region but deviates from the measurement data in the far wake region which may be due to the coarse resolution of the grid in this region. The influence of the SGS model on mean flow quantities as well as on the flow structures are also discussed.
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    Numerical simulation of laminar flow past a circular cylinder
    (2009) Rajani, B.N.; Kandasamy, A.; Majumdar, S.
    The present paper focuses on the analysis of two- and three-dimensional flow past a circular cylinder in different laminar flow regimes. In this simulation, an implicit pressure-based finite volume method is used for time-accurate computation of incompressible flow using second order accurate convective flux discretisation schemes. The computation results are validated against measurement data for mean surface pressure, skin friction coefficients, the size and strength of the recirculating wake for the steady flow regime and also for the Strouhal frequency of vortex shedding and the mean and RMS amplitude of the fluctuating aerodynamic coefficients for the unsteady periodic flow regime. The complex three dimensional flow structure of the cylinder wake is also reasonably captured by the present prediction procedure. 2008 Elsevier Inc. All rights reserved.
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    Numerical simulation of laminar flow past a circular cylinder
    (2009) Rajani, B.N.; Kandasamy, A.; Majumdar, S.
    The present paper focuses on the analysis of two- and three-dimensional flow past a circular cylinder in different laminar flow regimes. In this simulation, an implicit pressure-based finite volume method is used for time-accurate computation of incompressible flow using second order accurate convective flux discretisation schemes. The computation results are validated against measurement data for mean surface pressure, skin friction coefficients, the size and strength of the recirculating wake for the steady flow regime and also for the Strouhal frequency of vortex shedding and the mean and RMS amplitude of the fluctuating aerodynamic coefficients for the unsteady periodic flow regime. The complex three dimensional flow structure of the cylinder wake is also reasonably captured by the present prediction procedure. © 2008 Elsevier Inc. All rights reserved.
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    On the reliability of eddy viscosity based turbulence models in predicting turbulent flow past a circular cylinder using URANS approach
    (2012) Rajani, B.N.; Kandasamy, A.; Majumdar, S.
    Turbulent flow past circular cylinder at moderate to high Reynolds number has been analysed employing an secondorder time accurate pressure-based finite volume method solving two-dimensional Unsteady Reynolds Averaged Navier Stokes (URANS) equations for incompressible flow, coupled to eddy-viscosity based turbulence models. The major focus of the paper is to test the capabilities and limitations of the present turbulence model-based 2D URANS procedure to predict the phenomenon of Drag Crisis, usually manifested in reliable measurement data, as a sharp drop in the mean drag coefficient around a critical Reynolds number. The computation results are compared to corresponding measurement data for instantaneous aerodynamic coefficients and mean surface pressure and skin friction coefficients. Turbulence model-based URANS computations are in general found to be inadequate for correct prediction of the mean drag coefficients, the Strouhal number and also the coefficients of maximum fluctuating lift over the range of flow Reynolds number varying from 10 4 to 10 7.
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    On the reliability of eddy viscosity based turbulence models in predicting turbulent flow past a circular cylinder using URANS approach
    (2012) Rajani, B.N.; Kandasamy, A.; Majumdar, S.
    Turbulent flow past circular cylinder at moderate to high Reynolds number has been analysed employing an secondorder time accurate pressure-based finite volume method solving two-dimensional Unsteady Reynolds Averaged Navier Stokes (URANS) equations for incompressible flow, coupled to eddy-viscosity based turbulence models. The major focus of the paper is to test the capabilities and limitations of the present turbulence model-based 2D URANS procedure to predict the phenomenon of Drag Crisis, usually manifested in reliable measurement data, as a sharp drop in the mean drag coefficient around a critical Reynolds number. The computation results are compared to corresponding measurement data for instantaneous aerodynamic coefficients and mean surface pressure and skin friction coefficients. Turbulence model-based URANS computations are in general found to be inadequate for correct prediction of the mean drag coefficients, the Strouhal number and also the coefficients of maximum fluctuating lift over the range of flow Reynolds number varying from 10 4 to 10 7.